HIGH PERFORMANCE CONCRETE

HIGH PERFORMANCE CONCRETE (M70 GRADE)
A PROJECT REPORT
SUBMITTED IN PARTIAL FULFILLMENT OF THE REQUIREMENTS
FOR THE AWARD OF THE DEGREE
OF
BACHELOR OF TECHNOLOGY
IN
CIVIL ENGINEERING

SUBMITTED BY
GAURAV RATHOUR 2K14/CE/037
MANOJ KUMAR 2K14/CE/053
NIKHIL KR. SINGH 2K14/CE/057
NITESH KUMAR 2K14/CE/059
RITVIJ BHATI 2K14/CE/078

Under the supervision of
DR. MUNENDER KUMAR
(Associate Professor)

CIVIL ENGINEERING DEPARTMENT
DELHI TECHNOLOGICAL UNIVERSITY
(Formerly Delhi College of Engineering)
Bawana Road Delhi-110042
MAY, 2018

DECLARATION

We hereby declare that the project report entitled “High Performance Concrete (M70 Grade)” submitted by us to Delhi Technological University (formerly Delhi College of Engineering) for partial fulfilment of the requirement for the award of the degree of B. TECH in CIVIL ENGINEERING is a record of bona-fide project work carried out by us under the guidance of Dr. MUNENDER KUMAR. We further declare that the work reported in this project has not been submitted either in part or in full, for the award of any other degree or certificate in any other institute or university.

GAURAV RATHOUR 2K14/CE/037
MANOJ KUMAR 2K14/CE/053
NIKHIL KUMAR SINGH 2K14/CE/057
NITESH KUMAR 2K14/CE/059
RITVIJ BHATI 2K14/CE/078

i
CERTIFICATE

This is to certify that the above statement made by the GAURAV RATHOUR (2K14/CE/037), MANOJ KUMAR (2K14/CE/053), NIKHIL KUMAR SINGH (2K14/CE/057), NITESH KUMAR (2K14/CE/059), RITVIJ BHATI (2K14/CE/078) is correct to the best of my knowledge and belief.

Dr. MUNENDER KUMAR
Associate Professor
Department of Civil Engineering
Delhi Technological University

ii
ACKNOWLEDGEMENT

We would like to express our gratitude to our mentor, Dr. MUNENDER KUMAR who gave us the golden opportunity to carry out this wonderful project on the topic “HIGH PERFORMANCE CONCRETE (M70 GRADE)” which helped us in boosting our technical knowledge and experimental skills. His directions and support were the basic essence of motivation for us.
We feel of paucity of words to express our thanks to the honourable Head of Department of Civil Engineering, Dr. NIRENDRA DEV, for allowing us to utilize the department facilities and has been a constant source of motivation during the course of our project.
We express our deepest sense of gratitude towards the Professors of Civil Engineering Department who helped us in formulating the problem statement and clarifying our doubts regarding the learning about the high-performance concrete.
At last, we would like to thank our colleagues who helped us by actively participating in discussions and giving their valuable feedback. Their presence and support were invaluable.
Finally, we would like to thank our parents for their undying support, motivation and providing us the golden opportunity to study in this prestigious institution.

GAURAV RATHOUR 2K14/CE/037
MANOJ KUMAR 2K14/CE/053
NIKHIL KUMAR SINGH 2K14/CE/057
NITESH KUMAR 2K14/CE/059
RITVIJ BHATI 2K14/CE/078

iii
ABSTRACT
In this project work, mix design of M70 grade concrete and its major aspects has been covered by making use of Indian Standard of concrete mix design procedure. It is aimed at highlighting the importance of mix design concrete as compared to ordinary ratio analysed concrete in concrete production for any civil construction work. Therefore, we can analyse the merits and demerits of design and control of concrete production as mandatory by IS 456:2000 in structural requirement.
The method of concrete mix design includes selection of optimum proportions of ingredients, i.e., water, cement, fine and coarse aggregates and admixtures to produce concrete of stated properties such as strength, workability, durability, etc. as economically as possible. The compressive strength of hardened concrete is generally taken as an index of its other properties and it depends upon many factors, for example, quality and quantity of cement, water, fine and coarse aggregates and batching, mixing, placing, compaction and curing.
This project work involves whole laboratory analysis of making trial mixes of M70 grade at different contents of silica fumes and superplasticizer. The design covered concrete grade 70 N/mm2 was designed to attain the required strength after 28 days of curing specially with water as minimum strength. Basically, the design concrete cubes were casted with ordinary Portland cement(OPC). It was equally considered as a factor that all the grade of concrete designed for, should achieve 65% strength after being cured for seven days in water. The individual result of the design mix was adequately presented and have shown that generally mix design of concrete before production as a measure of quality control of concrete work is very important in any civil construction work.

iv
CONTENTS
Declaration i
Certificate ii
Acknowledgement iii
Abstract iv
Chapter 1. Introduction 1
High Performance Concrete 1
Categorization of High-Performance Concrete 2
Materials Used in High-Performance Concrete 5
Concrete Mix Design 5
Requirements for Mix Design of Concrete 6
Types of Mixes 7
Factors affecting the choice of mix proportions 8
Mix Proportion designations 9
Factors to be considered for mix design 10
Chapter 2. Literature Review 11
2.1 Literature Review 11
2.2 Studies on High Performance concrete 12
2.2.1 Fresh Concrete 15
2.2.1.1 Workability 15
2.2.1.2 Curing 16
2.2.2 Hardened Concrete 16
2.2.2.1 Compressive strength 16
2.2.2.2 Bond Strength 16
2.2.2.3 Static and dynamic elastic modulus 16
2.2.2.4 Shrinkage and creep 17
2.2.2.5 Reinforcement 17
2.2.2.6 Impact Loading 18
2.2.2.7 Chloride Resistance 18
2.3 Properties of High Performance concrete 19
2.3.1 High Modulus of elasticity 19
2.3.2 High abrasion resistance 19
2.3.3 High durability and long life in severe environments 20
2.3.4 Low permeability and diffusion 20
2.3.5 Resistance to chemical attack 20
2.3.6 High resistance to frost and dicer scaling damage 20
2.3.7 Toughness and impact resistance 20
2.3.8 Ease of Placement 21
2.3.9 Chemical Attack 21
2.3.10 Carbonation 21
2.4 Methods for achieving High Performance Concrete 21
2.5 High Performance Concrete Parameters 22
2.6 Raw Materials and Proportions of High Performance Concrete 23
2.6.1 Cement 23
2.6.2 Fine Aggregate 24
2.6.3 Coarse Aggregate 26
2.6.3.1 Compressive strength of coarse aggregate 27
2.6.3.2 Shape of coarse aggregate 27
2.6.3.3 Maximum size of coarse aggregate 27
2.6.3.4 Effect of Aggregate Type 28
2.6.3.5 Effect of Aggregate Size 28
2.6.4 Mineral admixtures 30
2.6.4.1 Overview on Pozzolanas in Concrete 30
2.6.4.2 Silica fume 31
2.6.4.2.1 Efficiency of Silica Fume in Concrete 32
2.6.5 Admixtures 33
2.6.5.1 Studies on Superplasticizers 33
2.6.4.2 Objectives for using Superplasticizers 34
2.7 Mix Proportion 35
2.7.1 Typical HPC Mix Design Methods 36
2.7.2 Objective 36
Chapter 3. Mix Design of M70 Concrete Grade 37
3.1 Mix Details 37
3.2 Concrete Mix Design 37
3.2.1 Stipulations for Proportioning 37
3.2.2 Test Data for Materials 38
3.2.3 Design for 1m3 Batch (0% silica replacement) 38
3.2.3.1 Mix Calculation 40
3.2.3.2 Trial Mix Proportion 40
3.2.4 Design for 1m3 Batch (10% silica replacement) 41
3.2.4.1 Mix Calculation 41
3.2.4.2 Trial Mix Proportion 42
3.2.5 Design for 1m3 Batch (15% silica replacement) 42
3.2.5.1 Mix Calculation 43
3.2.5.2 Trial Mix Proportion 44
3.2.6 Design for 1m3 Batch (20% silica replacement) 44
3.2.6.1 Mix Calculation 45
3.2.6.2 Trial Mix Proportion 45
Chapter 4. Experimental Procedures 46
4.1. Cement 46
4.2 Coarse aggregates and Fine aggregates 46
4.2.1 Sieve Analysis (IS 383:2016) 47
4.3 Water 48
4.4 Super plasticizer (PLASTIMENT 2001NS) 48
4.5 Batching and mixing 49
4.6 Curing of concrete cubes 51
4.7 Compressive strength test (IS 516-1959) 51
Chapter 5. Results and Discussions 52
5.1 Results of Compression Strength Test 52
5.1.1 Compressive Strength after 7 days 55
5.1.2 Compressive Strength after 28 days 56
5.2 Discussions 59
Chapter 6. Conclusion 60
References 61
Appendices 63

CHAPTER 1
INTRODUCTION
High Performance Concrete
High Performance Concrete(HPC) is well-defined as a concrete which meets all the possible aspects of performance and uniformity necessities that cannot always be attained regularly by using the conventional constituents and normal batching, mixing, placing, and curing practices. Ever since the term high-performance concrete was introduced into the industry, it had widely used in large-scale concrete construction that demands high strength, high flow ability, and high durability.
A high-strength concrete is always a high-performance concrete, but a high-performance concrete is not always a high-strength concrete. Durable concrete Specifying a high-strength concrete does not ensure that a durable concrete will be attained. It is very difficult to get a product which simultaneously fulfils all of the properties.
In recent years, more improvements in concrete properties are achieved in the area of High Performance Concrete by improvements like involving a recipe of improved compaction, improved paste characteristics, aggregate-matrix bond and reduced porosity (M.L. Gambhir, 2014) 1. Although high-performance concretes are made with the same basic components as the normal concrete, their much higher qualitative and quantitative performances make them new materials. On the basis of their use, they have different advantages like enhanced durability, reduced permeability, higher strength etc. at an economical cost (M.L. Gambhir, 2014).
High Performance Concrete (HPC) is manufactured carefully with selected high-quality ingredients and customized mixture designs. These are batched, mixed, placed, compacted and cured to the high-quality standards. Characteristically, this concrete will have a low water cement ratio of 0.20 to 0.40. Superplasticizers are typically used to make these concretes. However, strength is not always the principal required property. For example, a normal strength concrete with very high durability and very low permeability is considered in order to have high performance properties.
American Concrete Institute (ACI) 2 defines HPC as “A concrete which meets special performance and uniformity requirements that cannot always be attained routinely by using only conventional materials and normal mixing, placing and curing practices”. The requirements may involve enhancement of characteristics such as placement and compaction without segregation, long term mechanical properties, and early age strength or service life in severe environments. Concrete possessing many of these characteristics often achieve High Strength, but High Strength concrete may not be necessarily being of High Performance.
HPC can be designed to give optimized performance characteristics for a given set of load, usage and exposure conditions consistent with the requirements of cost, service life and durability. HPC does not require special equipment except careful design and production. HPC has several advantages like improved durability characteristics and much lesser micro cracking than normal strength concrete.
HPC significantly reduces construction time to permit rapid opening or reopening of roads to traffic, without compromising long term serviceability. Therefore, it is not possible to provide a unique definition of HPC without considering the performance requirements of the intended use of the concrete. HPC has been used in various structures all over the world since last two decades.
In India, it is about a decade old. Major applications in the constructions are nuclear power plants, high-rise buildings, and tall structures. Recently, few infrastructure projects have also seen specific application on HPC. Most of the developments across the work have been supported by continuous improvement of these admixtures. The development of HPC has brought about the essential need for additives both chemical and mineral to improve the performance of concrete. However, for better practical applications, behaviour of different structural elements like slabs, beams, columns etc., making of HPC need to be evaluated.

Admixtures plays an important role in the production of High Performance Concrete. Mineral Admixtures form an essential part of the High-Performance Concrete mix. They are used for various purposes depending upon their properties. Table-1.1 shows different types of mineral admixtures with their particle characteristics. We can see their classification on the basis of their activity and size.
Table 1.1 Mineral Admixtures used in High-Performance Concrete (HPC)
Mineral Admixtures Classification Characteristics
Ground granulated blast furnace slag

Cementitious and pozzolanic Unprocessed materials are grain like sand, ground to size less than 45 ?m.
Fly ash Cementitious and pozzolanic Powder consists of particles size less than 45 ?m.
Silica fume Highly active pozzolana Fine powder consisting of solid spheres of 0.1 ?m average diameter.

1.1.1 Categorization of High-Performance Concrete
A suitable classification of HPC according to different levels of performance requirements would enable design engineers to select appropriate performance criteria of HPC for different applications in different environmental conditions (M.L. Gambhir, 2014) 3. The categorization of high-performance concrete is as follows:

Based on Characteristic Strength
Based on 28-days characteristic strength of concrete, the following classification has been suggested
(a) Ordinary Concrete: Concrete having 28-days compressive strength in the range of 10 to 20 MPa.
(b) Standard/Normal Concrete: Concrete having 28-days compressive strength in the range of 25 to 55 MPa.
(c) High-Performance Concrete: Concrete having 28-days compressive strength in the range of 60 to 100 MPa.
(d) Very High-Performance Concrete: Concrete having 28-days compressive strength in the range of 100 to 150 MPa.
(e) Exceptional Concrete: Concrete having 28-days compressive strength more than 150 MPa.

Table 1.2 Concrete Grade Designated as
Group Grade Designation Characteristics of Compressive Strength of 150mm Cube At 28th Day N/?mm?^2
Ordinary Concrete M10
M15
M20 10
15
20
Standard Concrete M25
M30
M35
M40
M45
M50
M55 25
30
35
40
45
50
55
High Strength Concrete M60
M65
M70
M75
M80 60
65
70
75
80

Based on Durability and Target Strength
The Strategic Highway Research Programme(SHRP) has defined high-performance concrete into four categories as the concrete with
(a) A maximum water cement ratio of 0.35
(b) A minimum durability factor of 80 percent
(c) A minimum strength criterion
(d) Fibre Reinforcement

1.1.2 Materials Used in High-Performance Concrete
Cement
The choice of cement for high-strength concrete should not be based only on mortar-cube tests but it should also include tests of compressive strengths of concrete at 28, 56, and 91 days. A cement that yields the highest compressive strength at an extended age is preferable. For high-strength concrete, a cement should produce a minimum 7-days mortar-cube strength of approximately 30 MPa.

Aggregates
In high-performance concrete, size of the aggregates, their shape, surface texture, mineralogy, and clearness need special attention. For each source of aggregate and concrete strength level there is an optimum size aggregate that will yield the compressive strength per unit of cement. To find the optimum size, trial batches should be made with 20 mm and smaller coarse aggregates and varying cement contents.
In high-performance concretes, the strength of the aggregate itself and the bond between the paste and aggregate becomes a major factor. Tests have shown that crushed stone aggregates produce higher compressive strength in concrete than gravel aggregate using the same size aggregate and the same cementing materials content. This is probably due to a superior aggregate-to-paste bond when using rough, angular, crushed material.
Admixtures
Admixtures such as fly ash, silica fume, or slag are often necessary in the production of high-performance concrete. The gain in strength obtained with the addition of these admixtures cannot be attained by using additional cement alone. These admixtures are usually added at dosage rates of 5% to 20% or higher by mass of cementing material. The water-cement ratio should be adjusted so that equal workability becomes the basis of comparison between trial mixtures.
Concrete Mix Design
In order to meet the design requirements of any concrete structured project as per the standards, close supervision of the project and adequate concrete mix design should be done by the civil Engineer involved. In recent years, we have witnessed a lot of concrete structural failures either during the construction, after the completion or few years of the project age of completion, without satisfying design age of the project life.
The process of selecting suitable ingredients of concrete and defining their relative amounts with the objective of making a concrete of the required, strength, durability, and workability as economically as possible, is called as concrete mix design. The proportioning of ingredient of concrete is ruled by the required performance of concrete in two conditions, namely the plastic and the hardened condition. If the plastic concrete is not workable, it cannot be correctly placed and compacted. The property of workability, therefore, becomes of important.
The compressive strength of hardened concrete which is generally considered to be an index of its other properties that depends upon many factors like quality and quantity of cement, water and aggregates: batching and mixing: placing, compaction and curing. The cost of concrete is made up of the cost of materials, plant and labour. The variations in the cost of materials ascend from the fact that the cement is several times costly than the aggregate, thus the aim is to produce as lean a mix as possible. From technical point of view the rich mixes can lead to high shrinkage and cracking in the structural concrete, and to evolution of high heat of hydration in mass concrete which may cause cracking.
The actual cost of concrete is connected to the cost of materials obligatory for producing a minimum mean strength called characteristic strength that is stated by the designer of the structure. It depends on the quality control measures, but there is no doubt that the quality control adds to the cost of concrete. The extent of quality control is repeatedly an economic compromise, and depends on the size and type of job. The cost of labour rest on the workability of mix, e.g., a concrete mix of inadequate workability can result in a high cost of labour to obtain a degree of compaction with available equipment.
1.2.1 Requirements for Mix Design of Concrete
The requirements which are necessary for the selection and proportioning of the concrete mix ingredients are:
The minimum compressive strength essential from structural consideration.
The adequate workability essential for full compaction with the compacting equipment available.
Maximum water-cement ratio and maximum cement content to give acceptable durability for the particular site conditions.
Maximum cement content to prevent shrinkage cracking due to temperature cycle in mass concrete.

1.2.2 Types of Mixes
Nominal Mixes
In the past, the specifications for concrete were arranged with the proportions of cement, fine and coarse aggregates. These mixes of fixed cement-aggregate ratio which ensures acceptable strength is termed nominal mixes. These offer simplicity and under normal conditions, have a margin of strength above that specified. However, due to the variability of mix ingredients the nominal concrete for a given workability varies extensively in strength.
Standard mixes
The nominal mixes of fixed cement-aggregate ratio (by volume) vary broadly in strength and can result in under- or over-rich mixes. For this reason, the minimum compressive strength has been comprised in many specifications. These mixes are termed standard mixes. IS 456-2000 has designated the concrete mixes into a number of grades as M10, M15, M20, M25, M30, M35 and M40. In this designation the letter M refers to the mix and the number to the specified 28-day cube strength of mix in N/?mm?^2. The mixes of grades M10, M15, M20 and M25 resemble approximately to the mix proportions (1:3:6), (1:2:4), (1:1.5:3) and (1:1:2) respectively.
Designed Mixes
In these mixes, the performance of the concrete is detailed by the designer but the mix proportions are determined by the producer of concrete, except that the minimum cement content can be put down. This is most rational approach to the selection of mix proportions with specific materials in mind possessing more or less inimitable characteristics. The approach results in the production of concrete with the appropriate properties most economically. However, the designed mix does not serve as a guide since this does not guarantee the correct mix proportions for the agreed performance.
For the concrete with undemanding performance nominal or standard mixes (prescribed in the codes by quantities of dry ingredients per cubic meter and by slump) may be used only for very small jobs, when the 28-day strength of concrete does not exceed 30 N/?mm?^2. No control testing is necessary reliance being placed on the masses of the ingredients.

1.2.3 Factors affecting the choice of mix proportions
The various factors affecting the mix design are:
Compressive strength
It is one of the most important properties of concrete and effects many other describable properties of the hardened concrete. The other factor affecting the strength of concrete at a given age and cured at a agreed temperature is the degree of compaction. The mean compressive strength essential at a specific age, usually 28 days, determines the nominal water-cement ratio of the mix. According to Abraham’s law, the strength of fully compacted concrete is inversely proportional to the water cement ratio.
Workability
The degree of workability required rest on on three factors. These are the size of the section to be concreted and the method of compaction to be used. This also smears to the embedded steel sections. The desired workability hangs on on the compacting equipment available at the site. For the narrow and complicated section with many corners or inaccessible parts, the concrete must have high workability so that full compaction can be attained with a reasonable amount of effort.
Durability
The durability of a concrete is its resistance to the aggressive environmental conditions. In these situations when the high strength is not essential but conditions of exposure are such that high durability is vital, the durability requirement will control the water cement ratio to be used. High strength concrete is generally more durable than low strength concrete.

Maximum nominal size of aggregate
In general, larger the maximum size of aggregate, smaller is the cement requirement for a particular water-cement ratio, because the workability of concrete increases with increase in maximum size of the aggregate. However, the compressive strength tends to increase with the decrease in size of aggregate. IS 456:2000 and IS 1343:2016 recommends that the nominal size of the aggregate should be as large as possible.
Grading and type of aggregate
The grading of aggregate influences the mix proportions for a stated workability and water-cement ratio. The type of aggregate influences strongly the aggregate-cement ratio for the desired workability and specified water cement ratio. Coarser the grading leaner will be mix which can be used. Very lean mix is not looked-for since it does not contain plenty finer material to make the concrete cohesive. An important feature of a satisfactory aggregate is the uniformity of the grading which can be attained by mixing different size fractions.
Quality Control
The degree of control can be assessed statistically by study of variations in test results. The variation in strength results from the variations in the properties of the mix ingredients and absence of control of accuracy in batching, mixing, placing, curing and testing. The lesser the difference between the mean and minimum strengths of the mix lower will be the cement content required. The factor governing this difference is termed as quality control.

1.2.4 Mix Proportion designations
The common method of expressing the proportions of ingredients of a concrete mix is in the terms of parts or ratios of cement, fine and coarse aggregates. For e.g., a concrete mix of proportions 1:2:4 means that cement, fine and coarse aggregate are in the ratio 1:2:4 or the mix contains one part of cement, two parts of fine aggregate and four parts of coarse aggregate. The water-cement ratio is usually expressed in mass. The proportions are either by volume or by mass.

Factors to be considered for mix design
The grade designation that gives the characteristic strength requirement of concrete.
The type of cement effects the rate of development of compressive strength of concrete.
The cement content is to be restricted from shrinkage, cracking and creep.
Maximum nominal size of aggregates to be used in concrete can be as large as possible within the limits prescribed by IS 456:2000.
The workability of concrete for satisfactory placing and compaction is linked to the shape and size of section, spacing and quantity of reinforcement and technique being used for transport, placing and compaction.

CHAPTER 2
LITERATURE REVIEW
2.1 Literature Review
Concrete may be defined as a solid mass made by the use of a cementing medium, generally the ingredients compose of cement, sand, gravel and water. Concrete has been in use as a building material for more than a hundred and fifty years. Its success and popularity may be largely attributed to
Durability under hostile environments
Ease with which it can be cast into a variety of shapes and size
Its relative economy and easy availability.
Concrete is remarkably strong in compression but it is equally weak in tension. Hence, the use of plain concrete as a structural material is limited to situations where significant tensile stresses and strains do not develop.
Concrete is defined as “High Strength Concrete” solely on the basis of its compressive strength measured at a given age. The term “High Performance Concrete (HPC)” is used for concrete mixtures possessing high workability, high durability and high ultimate strength. Following are the points to be noted about high-performance concrete:
Concrete whose constituents, proportions and production approaches are precisely chosen in order to meet special performance and uniformity aspects that cannot be always attained regularly by using only conventional materials like cement, aggregates, water and chemical admixtures and adopting normal batching, mixing, placing and curing tasks. These necessities can be high strength, high early strength, high workability, low permeability and high durability for severe service environments, etc. or combinations thereof.
Aitcin74 describes about HPC, it is a concrete, which possess high durability and high strength when compared to conventional concrete. This concrete comprises one or more of cementitious materials such as fly ash, Silica fume or Ground granulated blast furnace slag(GGBFS) and usually a superplasticizer. The term ‘high performance’ is somewhat pretentious because the essential feature of this concrete is that its ingredients and proportions are specifically chosen so as to have particularly appropriate properties for the expected use of the structure such as high strength and low permeability.
High Performance Concrete(HPC) is a concrete of special properties, which exceeds the properties and construction aspects of normal concrete. Special mixing, placing, and curing practices may be needed to produce and handle HPC. Normal and special materials are used which make these concretes that must meet a combination of performance requirements. Extensive performance tests are usually required to demonstrate compliance with specific project needs. HPC has been mainly used in tunnels, bridges for its strength, durability, and high modulus of elasticity. It has also been used in shotcrete repair, Irrigation structures, poles, parking garages.
High performance concrete (HPC) is a specialized type of concrete intended to provide numerous aids in the construction of concrete structures that cannot always be attained routinely using conventional ingredients, normal mixing and curing practices. Production and use of such concrete in the field necessitates high degree of uniformity between batches and very rigorous quality control.
While high strength concrete, aims at increasing strength and consequential advantages owing to improved strength, the term high-performance concrete (HPC) is used to refer to concrete of required performance for the majority of construction applications without compromising long-term serviceability. It may also include concrete, which expressively reduces construction time without cooperating long-term serviceability.
In the other words, HPC is a concrete in which certain characteristics are developed for a particular application and environment, so that it will give excellent performance in the structure in which it will be placed, in the environment to which it will be exposed, and with the loads to which it will be subjected during its design life. It includes concrete that provides either noticeably improved resistance to environmental influences or noticeably increased structural capacity while maintaining adequate durability.
While high strength concrete, aims at enhancing strength and subsequent benefits owing to improved strength, the term high-performance concrete (HPC) is used to discuss to concrete of required performance for the majority of construction applications.
HPC works out to be economical, even though its initial cost is higher than that of conventional concrete because, the use of HPC in construction enhances the service life of the structure and the structure suffers less damage which will reduce overall cost.
2.2 Studies on High Performance concrete
High-Performance-Concrete (HPC) has been defined as concrete that possesses high workability, high strength and high durability. ACI (American Concrete Institute) 5 has defined HPC as a concrete in which certain characteristics are established for a particular application and environment. ACI also describes a high-strength concrete as concrete that has a specified compressive strength for design of 6,000 psi (41 MPa) or greater. Under the ACI definition durability is optional and this has directed to a number of HPC structures, which should theoretically have had very long services lives, exhibiting durability associated distress early in their lives.
A mix of high performance concrete was described by Ozawa et al. (1990) 6, which is defined as a concrete with high filling capacity. It can be filled into all the corners of formwork without using any vibrators. The study is important for developing the concrete with high filling capacity. The objective of this study was to examine the role of chemical admixtures such as superplasticizer and viscosity agents on the deformational and segregation behaviour of fresh concrete. The optimum mix proportion of superplasticizer and viscosity agent was explained for the concrete with high filling capacity. It was found that there exists the suitable viscosity of paste for improving not only the deformability but also the segregation resistance, which is highly dependent on the volume of free water in fresh concrete.
Mehta and Aitcin (1990) 7 suggested the term High Performance Concrete for concrete mixtures that possess the three properties: high-workability, high-strength, and high durability. Durability somewhat than high strength seems to be the principal characteristic for high-performance concrete mixtures being established for use in hostile environments such as seafloor tunnels, offshore and coastal marine structures, and detention for solid and liquid wastes containing hazardous materials. Strength, dimensional stability, impermeability, and high workability are typically the principal characteristics obligatory of high-performance concrete. In this paper an overview of the composition of concrete and its effect on the properties desired for high performance is given. This overview might be used as a basis for selection of component materials and mix proportioning. A new step-by-step procedure for mix proportioning is described. The calculated mix proportions from this procedure appear to be consistent with the state of art laboratory and field practice. Also, a short-term review is given of concrete production and construction practices essential for making a high-performance end product.
In discussing the meaning of HPC, Aitcin and Neville (1993) 8 stated that “in practical application of this type of concrete, the emphasis has in many cases gradually shifted from the compressive strength to other properties of the material, such as a high modulus of elasticity, high density, low permeability, and resistance to some forms of attack.”
HPC was defined by Forster (1994) 9 as “a concrete which is made with suitable materials combined conferring to a selected mix design and properly mixed, transported, placed, consolidated, and cured such that the resulting concrete will give admirable performance in the structure in which it will be exposed, and with the loads to which it will be exposed for its design life.”
High-Performance-Concrete (HPC) is a concrete made with appropriate materials combined according to a selected mix design: properly mixed, transported, placed, consolidated and cured so that the resulting concrete will give excellent performance in the structure in which it is placed, in the environment to which it is exposed and with the loads to which it will be subject for its design life. The main application for HPC have been structures necessitating long service lives such as oil drilling platform, long span bridges and parking structures. Mix proportions for high-performance concrete (HPC) are affected by many factors, including specified performance properties, locally available materials, local experience, personal preferences, and cost. By today’s technology, there are several products available for use in concrete to enhance its properties. HPC still requires good construction practice and good curing to deliver high performance. The Federal Highway Administration (FHWA) 10 has proposed criteria for four different performance grades of HPC (Goodspeed et al., 1996). The criteria are expressed in terms of eight performance characteristics including strength, elasticity, freezing/thawing durability, chloride permeability, abrasion resistance, scaling resistance, shrinkage, and creep. Depending on a specific application, a given HPC may require different grade of performance for each performance characteristics. For example, a bridge located in an urban area with moderate climate may require different performance for strength, elasticity, shrinkage, creep, and abrasion resistance, compared to performance for freezing/thawing durability, scaling resistance, and chloride permeability.
Concrete is a commonly used construction material around the world, and its properties have been undergoing changes through technological progression. Currently, high-performance concrete is used in massive volumes due to its technical and economic advantages. Nima Farzadni et al. (2011) 11 say that with a fast population growth and a higher demand for housing and infrastructure, accompanied by recent growths in civil engineering, such as high-rise buildings and long-span bridges, higher compressive strength concrete is needed. Such materials are categorized by improved mechanical and durability properties resulting from the use of chemical and mineral admixtures as well as specialized production processes.
The various engineering properties which were concluded on the basis of experiments and researches are as follows:

2.2.1 Fresh Concrete
The various properties of fresh concrete are as follows.
2.2.1.1 Workability
Tsong Yen (1999) 12 studied the effects of materials and rheological properties. A new rheometer was established by conducting a two-point test to investigate the flow behaviour of high strength HPC. Test results showed that the high strength HPC with good uniformity and without tendency of segregation can possess the properties of rheology according to Bingham’s equation. An increase of the fraction of mortar in HPC can lead to a more distinct rheological behaviour. Moreover, it is found that the application of a rheological method can provide more stable results than any other test method in describing the flowability of high strength HPC.

2.2.1.2 Curing
Bushlaibi (2004) 13 investigated the compressive strength of silica fume high performance concrete under different curing methods. The concrete specimens were kept under five different curing conditions and in two different environments for a period of 9 months. The curing conditions used were water curing (Control), no curing, sprinkle curing, plastic curing and burlap curing. Each of the last four conditions was exposed to two different environments indoor environment and outdoor environment. The strength results were determined at 1, 3, 7, 14, 28 and 270 days. Concluded indoor samples were more sensitive to curing than those cured outdoor. In the case of the outdoor all these curing methods give similar results due to the arid nature of hot climate.
2.2.2 Hardened Concrete
The various properties of hardened concrete are as follows.
2.2.2.1 Compressive strength
Debabratha and Dutta (2013) 14 studied the influence of silica fume on normal concrete with replacement of cement by silica fume. Five mixes were prepared with 0, 5, 10, 15 and 20% of silica fume with constant water-cement ratio of 0.4. Cube compressive strengths were determined for all the mixes and concluded that 20% replacement of cement by silica fume attained higher strengths and also observed that the failure plane cut the aggregates but not the interfacial zone. Interfacial zone attained higher strength than the normal concrete without silica fume.
2.2.2.2 Bond Strength
Fu et al., (1998) 15 conducted experiments on bond strength between concrete, steel rebar using silica fume and methylcellulose as admixture and concluded that the combined use of silica fume (15% by weight of cement) and methylcellulose (0.4% by weight of cement) as admixtures was found to give concrete that exhibited high bond strength to steel rebar. The bond strength attained was higher than those attained by using either silica fume or methylcellulose.
2.2.2.3 Static and dynamic elastic modulus
Mostofinejad and Nozhati (2005) 16 prepare a model to predict the modulus of elasticity of high strength concrete based on some known characteristic of the concrete mix. Forty-five mix proportions including 5 different ratios of silica fume (0, 5, 10, 15 and 20%), three water to cementitious materials ratio (0.24, 0.3 and 0.4) and three types of coarse aggregates, (limestone, quartzite and andesitic) were selected. 540-cylinder specimens were cast, cured and tested after 7, 28 and 91 days. Different ratios of silica fume different ratios of water to cementitious materials, the relationship of modulus of elasticity of coarse aggregate and concrete at different ages were discussed and also proposed empirical equations.
2.2.2.4 Shrinkage and creep
Cusson and Margeson (2010) 17 conducted experimentation and evaluated the mechanical, chemical and durability characteristics of different formulations of normal density, air entrained high-performance concrete with a water-cement ratio of 0.35 and concluded that HPC is prone to early age cracking when shrinkage is restrained in concrete structures.
Ahmed et al., (2012) conducted experimentation on shrinkage behaviour of concrete for 1-year observation using three mineral additions. The tests were carried out on mortar specimens with replacement of cement by 5, 15 and 25% of lime stone, 10, 30 and 50% of slag and 10, 20 and 30% of limestone powder. Optimum improvement of compressive strength of mortar was obtained at substitution of cement by 10% of lime stone, 20% of natural pozzolan and 30% of slag. Presence of limestone in the mortar improved the microstructure.
2.2.2.5 Reinforcement
Abu Zakir Morshed et al., (2014) investigated the effects between corrosion of reinforcement and pre-loading. Three concrete specimens of size 1170x100x150mm were used as test specimens. Two specimens were made of HPC incorporating silica fume and fly
ash, while the other as a control specimen of 100% cement as cement. The beams are reinforced with one 16 mm diameter bar and subjected to loading of four points at a constant load of 80% of the average ultimate flexural strength. Corrosion process was accelerated by 5% NaCl solution. Results revealed that initiation of corrosion followed liner trend for constant supply of external current and switched to an exponential trend when the current was increased. Concluded that concretes having silica fume and fly ash showed better resistance in respect of corrosion in terms of lower current density and lesser cumulative weight loss.
2.2.2.6 Impact Loading
Knab and Clifton (1982) 18 studied the methods of measuring the cumulative damage of steel reinforced concrete slabs subjected to repeated impact. Cumulative damage was monitored by measuring the crater depth and the reduction in ultrasonic pulse velocity across the impact region. Crater depth generally increased with increasing number of impacts and therefore, was determined to be a reasonable indicator of cumulative damage. The percent reduction in velocity generally increased with increasing number of impacts up to about 40
percent or more of the total number of impacts to failure. Beyond that, interpretation of the ultrasonic results with respect to the failure mechanism appears necessary. The addition of steel fibres to the bar grid reinforcement resulted in substantial increase (about 2 to 7 times
or more) in the total number of impacts to failure as compared to specimens with only bar grid or expanded metal placed at the midpoint of the slab thickness.
Sidney Mindess et al., (1987) studied the fracture toughness of plain concrete, high strength concrete and concrete reinforced with fibrillated polypropylene fibres. Single edge notched beams, of dimensions 1400×100×125 mm, were loaded dynamically in 3-point bending, using an instrumented drop weight impact machine. Fracture energies and dynamic fracture toughness (KID) values were determined, using three different drop heights of the impact hammer. It was found that, for all three types of concrete, KID increased with increasing drop height, the fracture toughness values under impact loading were much higher than those obtained in static tests. There were also dramatic increases in the fracture energies under impact loading.
2.2.2.7 Chloride Resistance
Vagelis (2000) 19 investigated the durability of cement incorporating cementing materials silica fume, low-and high-calcium fly ash (SCM). Experimental tests were carried to simulate the deterioration mechanism in reinforced cement concrete (Chloride penetration and carbonation). It was found that the carbonation depth decreases as aggregate replacement by SCM increases. The specimen incorporates SCM, by substitutes aggregate or cement exposed to chlorides exhibit lower total chloride content for all depths from the surface. Estimated new parameter values and existing models were modified to describe the chloride penetration and carbonation propagation in concrete incorporation of SCM.

2.3 Properties of High Performance concrete
Following are some of the significant properties of High Performance Concrete
Ease of placement
Low permeability and diffusion
High resistance to frost and de-icer scaling damage
High abrasion resistance
Toughness and impact resistance
High modulus of elasticity
Resistance to chemical attack
High durability and long life in severe environments
Chemical Attack
Carbonation
2.3.1 High Modulus of elasticity
The modulus of elasticity is a very important mechanical property of concrete. The higher the value of the modulus, the stiffer the material is. Thus, comparing a high-performance concrete to a normal strength concrete, it is seen that the elastic modulus for high performance concrete will be higher, thereby making it a stiffer type of concrete. Stiffness is a desirable property for concrete to have because the deflection a structure may experience will be decreased. However, deformations, such as creep, increase in high strength concrete.
2.3.2 High abrasion resistance
Abrasion resistance is directly related to the strength of concrete. This makes high-performance concrete ideal for abrasive environments. The abrasion resistance of HPC incorporating silica fume is especially high. This makes silica fume concrete particularly useful for spillways and stilling basins, and concrete pavements or concrete pavement overlays subjected to heavy or abrasive traffic.

2.3.3 High durability and long life in severe environments
Durability problems of ordinary concrete can be associated with the severity of the environment and the use of inappropriate high water/cement ratios. High-performance concrete that have a water/cement ratio between 0.25 and 0.35 are usually more durable than ordinary concrete not only because they are less porous, but also because their capillary and pore networks are somewhat disconnected due to the development of self-desiccation. In high-performance concrete (HPC), the penetration of aggressive agents is quite difficult and only superficial.
Low permeability and diffusion
The durability and service life of concrete exposed to weather is related to the permeability of the cover concrete protecting the reinforcement. HPC typically has very low permeability to air, water, and chloride ions. Low permeability is often specified through the use of a coulomb value, such as maximum of 1000 coulombs (By chloride Permeability test for concrete). The dense pore structure of high-performance concrete, which makes it so impermeable, gives it characteristics that make it eminently suitable for uses where a high-quality concrete would not normally be considered.
2.3.5 Resistance to chemical attack
For resistance to chemical attack on most structures, HPC offers a much-improved performance. Resistance to various sulphates is attained primarily by the use of a dense, strong concrete of very low permeability and low water-to-cementing materials ratio: these are all characteristics of HPC. Similarly, resistance to acid from wastes is also much improved.
2.3.6 High resistance to frost and de-icer scaling damage
Because of its very low water-cementing materials ratio (less than 0.30), it is widely believed that HPC should be highly resistant to both scaling and physical breakup due to freezing and thawing. There is ample evidence that properly air-entrained high-performance concretes are highly resistant to freezing and thawing and to scaling.
2.3.7 Toughness and impact resistance
Both normal-strength concrete and high-strength concrete are brittle, with the degree of brittleness increasing with increasing strength. The dynamic mechanical performance of high strength concrete (HSC) under impact or fatigue loading has received increasing attention in recent years because of the rapid adoption of higher strength concrete in bridges, pavements, and marine structures, and several researchers have studied the impact or fatigue performance of concrete.
Many experimental results have indicated that the characteristics and microstructure of both the interfacial zone and the bulk HSC are improved by incorporating silica fume. As well, the addition of steel fibres can effectively restrain the initiation and propagation of crack under stress, and improve the toughness.
Ease of Placement
High performance concrete can also be highly workable self-compacting concrete which is type of HPC which can be easily placed even dense reinforcement where vibrators can’t be used.
2.3.9 Chemical Attack
For confrontation to chemical attack on most structures, HPC offers a much-improved performance. Resistance to various sulphates is attained primarily by the use of a dense, strong concrete of very low permeability and low water-to-cementing materials ratio: these are all features of HPC. Similarly, resistance to acid from wastes is also much upgraded.
Carbonation
High Performance Concrete has a very good resistance against carbonation due to its low permeability. It was determined that after 17 years the concrete in the CN Tower in Toronto had carbonated to an average depth of 6 mm (0.24 inch). For a cover to the reinforcement of 35 mm (1.4 inch), this concrete would offer corrosion protection for 500 years. The concrete mixture in the CN Tower had a water cement ratio of 0.42. For the lower water cementing materials ratios common to HPC, significantly longer times to corrosion would result, assuming a crack free structure.

2.4 Methods for achieving High Performance Concrete
In universal, better durability performance has been attained by using high-strength, low water cement ratio concrete. Though, in this approach the design is based on strength and the result is better durability, it is needed that the high performance, that is, the durability, is addressed directly by augmenting critical parameters such as the practical size of the required materials.
Two approaches to achieve durability through different techniques are as follows:
Reducing the capillary pore system such that no fluid movement can occur is the first approach. This is very difficult to realize and all concrete will have some interconnected pores.
Making chemically active binding sites which stop transport of aggressive ions such as chlorides is the second more effective method.

2.5 High Performance Concrete Parameters
Permeation is a major factor that causes premature deterioration of concrete structures. The establishment of high-performance concrete must emphasis on minimising permeability through proportioning methods and suitable construction procedures like curing in order to confirm that the exposure conditions do not cause ingress of moisture and other agents accountable for deterioration.
It is important to recognize the leading transport phenomenon and design the mix proportion with the aim of reducing that transport mechanism which is leading to a predefined acceptable performance limit based on permeability.
The parameter to be controlled for achieving the required performance criteria could be any of the following:
(1) Water/ (cement and/or mineral admixture) ratio
(2) Strength
(3) Low free lime content
(4) Densification of cement paste
(5) Removal of bleeding
(6) Strong transition zone
(7) Homogeneity of the mix
(8) Particle size distribution
(9) Dispersal of cement in the fresh mix
(10) Very slight free water in hardened concrete
2.6 Raw Materials and Proportions of High Performance Concrete
The main ingredients of HPC are almost the same as that of conventional concrete.
These are
1) Cement
2) Fine aggregate
3) Coarse aggregate
4) Water
5) Mineral admixtures (fine filler and/or pozzolanic supplementary cementation materials)
6) Chemical admixtures (plasticizers, superplasticizers, retarders, air-entraining agents)

Cement
There are two important requirements for any cement:
(a) Strength development with time and
(b) Facilitating appropriate rheological characteristics when fresh.
High C3A content in cement generally leads to a rapid loss of flow in freshly made concrete. Therefore, high C3A content should be sidestepped in cements used for HPC.
The fineness of cement is the serious parameter. Enhancing fineness increases early strength development, but it may lead to rheological deficiency.
The total amount of soluble sulphate present in cement is a fundamental consideration for the suitability of cement for HPC.
The compatibility of cement with retarders, if it is used, is also a vital requirement.
The super plasticizer which are used in HPC should have a long molecular chain in which the sulphonate group resides the beta position in the poly condensate of formaldehyde and melamine sulphonate or that of naphthalene sulphonate.

Table 2.1. Minimum cement content, Maximum water cement ratio and Minimum grade
of concrete for various exposure conditions for 20mm nominal size
Aggregates of normal weight.
Exposure Plain concrete Reinforced concrete
Min. cement (kg/m3) Max. water cement ratio Min. grade Min. cement
(kg/m3) Max. water cement ratio Min. grade
Mild 220 0.6 – 300 0.55 M 20
Moderate 240 0.6 M 15 300 0.5 M 25
Severe 250 0.5 M 20 320 0.45 M 30
Very severe 260 0.45 M 20 340 0.45 M 35
Extreme 280 0.4 M 25 360 0.4 M 40

Fine aggregate
Fine aggregates (FA) with a rounded particle shape and smooth texture have been found to require less mixing water in concrete and for this reason are preferable in HPC. HPC characteristically contain such high contents of fine cementitious materials that the grading of the FA used is relatively unimportant. However, it is occasionally helpful to increase the fineness modulus (FM) as the lower Fineness Modulus of fine aggregates can bring the concrete a sticky consistency (i.e. making concrete difficult to compact) and less workable fresh concrete with a greater water demand. Therefore, sand with a FM of about 3.0 is usually preferred for HPC.
The grading of fine aggregate when determined as described in IS 2386-part1 shall be within the limits given in table 2.2. and shall be described as fine aggregate, grading zones I, II, III and IV. Where the grading falls outside the limits of any particular sieve size, it shall be regarded as failing within that grading zone. This tolerance shall not be applied to percentage passing any other sieve size on the coarse limit of Grading Zone I or the finer limit of Grading zone IV.

Table 2.2. Fine Aggregate Grading Zones and Percentage passing range.
IS sieve Percentage passing
Grading Zone I Grading Zone II Grading Zone III Grading Zone IV
10 mm 100 100 100 100
4.75 mm 90-100 90-100 90-100 95-100
2.36 mm 60-95 75-100 85-100 95-100
1.18 mm 30-70 55-90 75-100 90-100
600 µ 15-34 35-59 60-79 80-100
300 µ 5-20 8-30 12-40 15-50
150 µ 0-10 0-10 0-10 0-15

Table 2.3. Limits of Deleterious materials for Fine Aggregates.
Deleterious material Method of test refer to Fine Aggregate % by mass, max
Uncrushed Crushed/mixed Manufactured
Coal and lignite IS 2386 (Part 2) 1.00 1.00 1.00
Clay lumps IS 2386 (Part 2) 1.00 1.00 1.00
Materials finer than 75 microns IS 2386 (Part 1) 3.00 15.00 10.00
Soft fragments IS 2386 (Part 2) – – –
Shale – 1.00 – 1.00
Total % of all deleterious materials – 5.00 2.00 2.00

Coarse aggregates
The important parameters of coarse aggregate that effect the performance of concrete are its shape, texture and the maximum size. Since the aggregate is generally sturdier than the paste, its strength is not a major factor for normal strength concrete. The surface texture, consequently, may also affect the modulus of elasticity, the shape of the stress strain curve and to a lesser degree, the compressive strength of concrete. Though, the aggregate’s strength plays an important role in case of high performance concrete. Surface texture and mineralogy interrupt the bond between the aggregates and the paste as well as stress level at which micro cracking starts. Since bond strength increases at a slower rate than compressive strength, these effects will be extra noticeable in High Early Strength concrete. Tensile strengths may be very sensitive to modifications in aggregate surface texture and surface area per unit volume.
Table 2.4. Limits of deleterious materials for Coarse Aggregates.
Deleterious material Method of test refer to Coarse aggregate % by mass, max
Uncrushed Crushed/mixed Manufactured
Coal and lignite IS 2386 (Part 2) 1.00 1.00 1.00
Clay lumps IS 2386 (Part 2) 1.00 1.00 1.00
Materials finer than 75 microns IS 2386 (Part 1) 1.00 1.00 1.00
Soft fragments IS 2386 (Part 2) 3.00 – 3.00
Shale – – – –
Total % of all deleterious materials – 5.00 2.00 2.00

The maximum quantity of deleterious materials shall not exceed the values given in table 2.3. and table 2.4. However, the Engineer in charge at his discretion may relax some of the limits as a result of some further tests and evidence of satisfactory performance of the aggregates.
2.6.3.1 Compressive strength of coarse aggregate
To make high-strength concrete we must apparently use coarse aggregate that has a high compressive strength to avoid rupture from occurring in the coarse therefore find coarse aggregates that come from quarries that yield rocks with compressive strengths above 16,500 psi and absolutely avoid rocks that are too soft or which present cleavage planes. Hence, before making the laboratory trial batches, we should determine the compressive strengths of all the coarse aggregates economically available. As already noted, it is not necessarily the toughest coarse aggregate which will produce the strongest concrete, since the bond of the hydrated cement to that same aggregate should be taken into account.
2.6.3.2 Shape of coarse aggregate
Since the bond between the coarse aggregate and the hydrated cement is mainly of a mechanical type at the beginning, to make high-strength concrete we ought to use a cubically shaped crushed stone rather than a natural gravel or a crushed gravel. The type of crusher used by the aggregate producer is vital in this respect. Furthermore, the surfaces of the coarse aggregate must be clean and free of any dust which would damage mechanical bonding. In certain cases, washing of the aggregate may prove essential. Watchful examination of aggregate samples from local quarries is adequate to choose the coarse aggregate that offers the most useful characteristics from this point of view.
2.6.3.3 Maximum size of coarse aggregate
We can illustrate that for a given aggregate there is a relation between its maximum diameter and the maximum compressive strength probable from concrete made with it. The absolute maximum strength appears to be obtained with aggregates having a maximum size of 3 ? 8 or 1 ? 2 inch. 8 Standard coarse aggregates of no. 4 to- 3 ? 8 -inch 9 or no. 4-to-5 ? 8 -inch, 10 sizes are the most suitable.

2.6.3.4 Effect of Aggregate Type
The inherent strength of coarse aggregate is not an important factor if water-cement ratio falls within the range of 0.50 to 0.70, mainly due to the fact that the cement-aggregate bond or the hydrated cement paste fails long before aggregates do. It is, however, not true for high strength concretes with very low water-cement ratio of 0.20 to 0.32. For such concretes, aggregates can assume the weaker-link role and fail in the form of trans granular fractures on the failure surface. However, the aggregate minerals must be strong, unaltered, and fine grained in order to be suitable for high strength concrete. Intra and inter-granular fissures partially decomposed coarse-grained minerals, and the presence of cleavages and lamination planes tend to deteriorate the aggregate, and therefore the ultimate strength of the concrete.
The compressive strength and elastic modulus of concrete are significantly influenced by the mineralogical characteristics of the aggregates. Crushed aggregates from fine-grained debris and limestone give the best results. Concretes made from smooth river gravel and from crushed granite containing inclusions of a soft mineral are moderately weaker in strength. There occurs a good correlation between the compressive strength of coarse aggregate and its soundness expressed in terms of weight loss. There happens a close correlation between the mean compressive strengths of the aggregate and the compressive strength of the concrete, ranging from 35 to 75 MPa at both 7 days and 28 days of age.
2.6.3.5 Effect of Aggregate Size
The use of maximum nominal size of aggregate influences the strength in several ways. First, since larger aggregates have less specific surface area and the aggregate-paste bond strength is less, the compressive strength of concrete is decreased. Secondly, for a given volume of concrete, using larger aggregate outcomes in a smaller volume of paste thereby providing more restraint to the volume changes of the paste. This may bring additional stresses in the paste, resulting in micro cracks prior to application of load, which may be a critical factor in high strength concretes. Therefore, it is the general consent that smaller size aggregate should be used to produce high performance concrete.
It is generally suggested that 10 to 20 mm is the appropriate maximum size of aggregates for making high strength concrete. However, the acceptable performance and economy can also be attained with 20 to 25 mm maximum size graded aggregates by proper proportioning with a mid-range or high-range water reducer, high volume blended cements, and coarse ground Portland cement. Change in prominence from water-cementitious material ratio versus strength relation to water-content versus durability relation will provide the inducement for much closer control of aggregate grading than in the current practices.

Table 2.5.1 Coarse aggregates sizes and proportions.
Is sieve % Passing for Single Sized Aggregate of Nominal Size
63mm 40mm 20mm 16mm 12.5mm 10mm
80 mm 100 – – – – –
63 mm 85-100 100 – – – –
40 mm 0-30 85-100 100 – – –
20 mm 0-5 0-20 85-100 100 – –
16 mm – – – 85-100 100 –
12.5 mm – – – – 85-100 100
10 mm 0-5 0-5 0-20 0-30 0-45 85-100
4.75 mm – – 0-5 0-5 0-10 0-20
2.36 mm – – – – – 0-5

Table 2.5.2 Coarse aggregates sizes and proportions.
Is sieve % Passing for Graded Aggregate of Nominal Size
40 mm 20 mm 16 mm 12.5 mm
80 mm 100 – – –
63 mm – – – –
40 mm 90-100 100 – –
20 mm 30-70 90-100 100 100
16 mm – – 90-100 –
12.5 mm – – – 90-100
10 mm 10-35 25-55 30-70 40-85
4.75 mm 0-5 0-10 0-10 0-10
2.36 mm – – – –

Coarse aggregates shall be supplied in the nominal size as given in table 2.5.1. For any one of the nominal size, the proper proportion of the other sizes, as determined by the method described in IS 2386-part I shall be in accordance with table 2.5.1.
2.6.4 Mineral admixtures
Mineral admixtures are used for numerous purposes, depending upon their properties. They form a crucial and alternative pozzolanic part of the high-performance concrete mix. More than the chemical composition, mineralogical and granulometric characteristics decides the influence of mineral admixture’s role in enhancing properties of concrete.
2.6.4.1 Overview on Pozzolanas in Concrete
Pozzolanas are commonly used as an addition to Portland cement concrete mixtures to increase the long-term strength and other material properties. Pozzolana also known as pozzolanic ash is a fine sandy volcanic ash, originally discovered and dug in Italy at “Pozzuoli” in the region around Vesuvius. Pozzolana is a siliceous and aluminous material which reacts with calcium hydroxide in the presence of water to form compounds, a mix of natural or industrial pozzolanas and Portland cement. The Pozzolanic reaction is the chemical reaction that occurs in hydraulic cement, a mixture of slaked lime (calcium hydroxide) with amorphous siliceous materials namely, pozzolan or pozzolana, forming non-water-soluble calcium silicate hydrates.
At the basis of the Pozzolanic reaction stands a simple acid-base reaction between calcium hydroxide, also known as Portlandite, or (?Ca(OH)?_2), and silicic acid (H_4 ?SiO?_4or ?Si(OH)?_4). Simply, this reaction can be schematically represented as follows:
?Ca(OH)?_2 + H_4 ?SiO?_4 ? ?Ca?^(2+) + H_2 ?SiO?_4^(2-) + H_2O? ?CaH?_2 ?SiO?_4.?2H?_2O Eq. 1
or summarized in abbreviated notation of cement chemists:
CH + SH ? CSH Eq. 2
The product of general formula (?CaH?_2 ?SiO?_4.?2H?_2O) formed is a calcium silicate hydrate, also abbreviated as CSH in cement chemist notation.
The most commonly-used pozzolan today is fly ash though silica fume high reactivity metakaolin, ground granulated blast furnace slag and other materials are also used as pozzolanas.

Pozzolanic materials can be divided into two groups, namely
Natural Pozzolanic
Clay and Shales
Opalinc Cherts
Diatomaceous Earth
Volcanic tuffs
Pumicites
Artificial Pozzolanic
Fly ash
Blast furnace slag
Silica fume
Surkhi
Metakaolin
These pozzolanas react with OPC in two ways-by changing hydration process through alkali activated reaction kinetics of a pozzolana called pozzolanic reaction and by micro filler effect. In pozzolanic reaction the pozzolana react with calcium hydroxide, ?Ca(OH)?_2, (free lime) liberated during hydration of cement, which includes up to 25 per cent of the hydration product, and the water to fill voids with more calcium-silicate-hydrate (not evaporable water) that binds the aggregate particles together.
The pozzolanas may also react with other alkalis for example, sodium and potassium hydroxides present in the cement paste. These reactions decrease permeability, reduce the amounts of else harmful free lime and other alkalis in the paste, reduction of free water content, thus increase the strength and improve the durability.
2.6.4.2 Silica fume
In this project study, Silica fume was used as replacement with cement. Silica fume (SF) is probably the most common addition to concrete admixtures to produce HPC. This SF is also called condensed silica fume or micro silica. It is finely powdered amorphous silica that is highly pozzolanic. Silica fume varies from light to dark grey in colour. Its use is becoming so common around the world.
Silica fume is a by-product resulting from the reduction of high purity quartz with coa1 in electric arc furnaces in the manufacture of ferro-silicon and silicon metal. The fume, which has a high content of amorphous silicon dioxide and consists of very fine spherical particles, is collected by filtering the gases escaping from the furnaces. Silica fume contains large amounts of silicon dioxide (between 85 and 98%) and consists of extremely fine particles. It is collected by filtering the furnace gases. The average size of these spherical particles is less than 0.1micron, which is approximately one hundred times finer than cement. The extremely fine particles can fill spaces between cement particles, which results in a more refined microstructure and a denser cement paste. As the pores within the paste become finer and more dispersed, the permeability is reduced considerably.
Micro silica concrete has provided a low range of initial surface absorption varying from 28.1x?10?^(-2) to 4.3x?10?^(-2) ml/m^2/sec after 10 to 120 minutes. An initial surface absorption after 120 minutes is considered high if it becomes greater than 0.15 ml/m^2/sec and low if less than 0.07 ml/m^2/sec. The corresponding higher and lower values after 10 minutes are 0.5 and 0.25 ml/m^2/sec respectively. Physical properties of micro silica are low water absorption, colour is grey, specific gravity is 2.2 to 2.3 g/?cm?^3, specific surface is 15-30 m^2/g and the average particle size is around 0.1 micron.
Silica fume have a tendency to to improve both mechanical properties and durability. Silica fume not only offers an extremely rapid pozzolanic reaction, but it’s very fine size also offers a beneficial contribution to concrete. Silica fume is normally used in combination with high range water reducers and increase achievable strength levels intensely. Silica fume concretes continue to gain strength under a variety of curing conditions, including unfavourable ones. Therefore, the concretes with silica fume seem to be more robust to early drying than similar concretes that do not contain silica fume.
Since no interaction between silica fume, GGBFS and fly ash occurs, and each component manifests its own cementitious properties as hydration proceeds, higher strength and better flow ability can be attained by adding a combination of Silica Fume, Fly Ash and GGBFS to OPC which provides a system with wider particle size distribution.
2.6.4.2.1 Efficiency of Silica Fume in Concrete
Silica fume, like other pozzolanic materials, is generally more efficient in concretes having high water cement ratios. Investigations in Norway and Canada indicate that in concretes with a water-cement ratio of about 0.55 and higher, silica fume, when used in small percentages as cement replacement, has an efficiency factor of 3 to 4: for example, 1 kg of silica fume can replace 3 to 4 kg of cement in concrete and still result in concrete having the same compressive strength.
Admixtures
Superplasticizers (also Known as admixtures) are extensively used in concrete manufacturing in order to increase the rheological properties of hardened pastes. Superplasticizers are used in concrete like many other admixtures to perform a particular function, consequently they are frequently described according to their functional properties. Super plasticizers are chemical admixtures which can maintain a tolerable workability of fresh concrete at low water cement ratio for a sensible period of time, without affecting the setting and hardening behaviour of the cementitious system. Super plasticizers have been classified as high range water reducing admixtures (HRWRA) to distinguish them from other categories of less effective water reducers.
High Range Water Reducing Admixtures (HRWRA): These are the second-generation admixtures and are also known as Super plasticizers. These are the synthetic chemical products which are made from organic sulphonate of type ?RSO?_3, where R is complex organic group of higher molecular weight produced under cautiously controlled condition:
The commonly used super plasticizer are as follows:
Sulphonate Melamine Formaldehyde Condensate (SMFC)
Sulphonated Naphthalene Formaldehyde Condensate (SNFC)
Modified lignosulphonates and other sulphonic esters, acids etc.
Polycarboxylate Ether Polymer (PCE)
Studies on Superplasticizers
Franklin (1976) 20 stated that, the super plasticizers are organic electrolytes, which belong to the category of polymeric dispersants. The performance of super plasticizers in cementitious system is known to depend on cement fineness, cement composition mode of introduction to the mixture etc., as well as on the chemical composition of super plasticizers.
For many years, it was not possible to reduce water/cement ratio of concrete below 0.40 till the advent of super plasticizers. At first, the super plasticizers were used as fluidizers than water reducing agents. By consuming large enough super plasticizer, it was found possible to lower the water/cement ratio of concrete down to 0.30 and still get an initial slump of 200mm. The super plasticizers were first used in concrete in 1960s and their introduction occurred instantaneously in Germany and Japan (Meyer and Hottori, 1981). Reducing the water/cement ratio below 0.30 was a taboo until Bache reported that using a very high dosage of super plasticizers and silica fume, water cement ratio can be reduced to 0.16 to reach a compressive strength of 280MPa (Bache, 1981).
Aitcin et al. (1991) reported, that by selecting carefully the combination of Portland cement and superplasticizer. During 1980s, by increasing the dosage of super plasticizers little by little over the range specified by the manufacturers, it is realized that super plasticizers can be used as high range water reducers (Ronneberg and Sandvik, 1990)., it was possible to make a 0.17 water cement ratio concrete with 230mm slump after an hour of mixing which gave a compressive strength of 73.6MPa at 24 hours but failed to increase more than 125MPa after long term wet curing.

Table 2.6 Reduction in water cement Ratio against the different water reducing admixtures
Admixtures Reduction in water cement Ratio
Water Reducer Admixture 5-12%
Melamine/Naphthalene based admixture 16-25 %
Polycarboxylate ether polymer-based admixture 20 to 35%

2.6.5.2 Objectives for using Superplasticizers
The main objectives for using super plasticizers are the following:
To lessen the effect of heat of hydration by lowering the cement content.
To yield concrete with low air content and high workability to confirm high bond strength.
To yield concrete of lowest possible porosity in order to protect it against external attacks.
To overcome the problems of reduced workability in fibre reinforced concrete and shotcrete.
To lower the water cement ratio in order to keep the effect of creep and shrinkage to a minimum.
To keep alkali content low enough for protection against alkali aggregate reaction and to keep sulphate and chloride content as low as possible for inhibition of reinforcement corrosion.
To offer high degree of workability to the concrete having mineral additives with very low water cementitious material ratios.
To yield pump able yet non-segregating type concrete.
To yield highly dense concrete to confirm very low permeability with adequate resistance to freezing-hawing.
To yield highly ductile and acid resistant polymer concrete with adequate workability and strength.

2.7 Mix Proportion
The core difference between mix designs of High Performance Concrete(HPC) and Cement Concrete is the importance laid on performance aspect also (in fresh as well as hardened stages of concrete) as well as strength, in case of HPC, while in design of Cement Concrete mixes, strength of concrete is an important standard. In HPC, however, besides strength, durability considerations are given utmost importance. On imposing the limitations on maximum water cement ratio, minimum cement content, workability (slump, flow table, compaction factor, and Vee-Bee consistency tests), etc., it is required to guarantee performance of Cement Concrete: rarely any specific tests are done to measure the durability aspects of Cement Concrete, during the concrete mix design.
To achieve high durability of HPC, the mix design of HPC should be based on the following considerations:
The water cement ratio should be as less as possible preferably 0.3 and below.
The transition zone between aggregate and cement paste should be strengthened (add fine fillers such as silica fume).
The workability of concrete mix should be enough to obtain good compaction (use suitable chemical admixtures such as super plasticizer).
Proper curing regime of concrete should be followed (this is done in order to overcome the problems related with usual adoption of very low water content and high cement content in HPC mixes).
The microstructure of cement concrete should be made dense and impermeable (addition of pozzolanic materials such as fly ash, ground granulated blast furnace slag powder (GGBFSP), SF, etc.).

2.7.1 Typical HPC Mix Design Methods
The properties of HPC not only depend upon the water cement ratio but also vary considerably with the richness of mix and the type and strengths of concrete of aggregates. Workability of HPC depends upon the type of cement and its compatibility with chemical admixtures, shape of aggregates, method of mixing of ingredients of HPC, etc. Thus, the properties of materials and mix preparation techniques have very high effect on the HPC mixes, suitable mix proportions cannot be recommended for HPC. Therefore, any mix design procedure of HPC can strictly be only a guideline and a separate development of HPC mix in the laboratory for the various ingredients, type of structure and concreting conditions etc., is very much essential. Hence, the HPC mix design can be only application specific.
It should be noted that the strength increase as the water cement ratio is reduced (provided the compatibility of concrete is sustained), and that for a given water cement ratio, the strength is decreased as a mix is made richer (by addition of more cement) beyond a limit. Therefore, the advantage of increase in strength due to lowering of the water cement ratio, which also reduces consequently the workability. Hence, the HPC require approaches other than the increase of cement content in order to achieve the high strength. Though the strengths are not always true indicators of durability, the high strength associated with the HPC generally tend to impart also high durability to them, due to reduced water cement ratio and use of pozzolanic admixtures.
2.7.2 Objective
To study the different aspects of High Performance Concrete and hence achieve high strength concrete of grade M70 without compromising the workability of concrete. Normally when we try to attain very high strength the mix becomes very stiff and it can’t be pumped on the site. Thus, our main aim was to achieve the desired strength with anticipated workability and other properties like low permeability, high durability etc.

CHAPTER 3
MIX DESIGN OF M70 CONCRETE GRADE
3.1 Mix Details
In this chapter, Mix Design details for M70 concrete grade have been covered. Silica fume was used in concrete in different percentages, i.e., 0%, 10%, 15%, 20% to the weight of the cement. Twelve specimens were casted (three at each percentage) and tested for compressive strength in 7 days and 28 days.
Materials used in concrete mix are as follows:
Cement (OPC 43 Grade)
Fine Aggregates (sand of zone II)
Coarse Aggregates (Crushed Stone 20mm size)
Silica Fume
Superplasticizer (Plastiment 2001 NS)
Water

3.2 Concrete Mix Design
3.2.1 Stipulations for Proportioning
Grade M70
Type of cement OPC Grade 43 (IS 8112:1989)
Max. Nominal size of aggregate 20 mm
Minimum cement content 320 ?Kg/m?^3
Workability 75mm (Collapsible slump)
Method of concrete placing Pumping
Type of aggregate Crushed angular aggregate
Mineral admixture Silica Fume (IS 15388:2003)
Maximum cement content 550 ?Kg/m?^3
Chemical admixture type Plastiment 2001 NS (superplasticizer)

3.2.2 Test Data for Materials
Specific gravity of cement 3.15
Specific gravity of silica fume 2.2
Specific gravity of coarse aggregate 2.7
Specific gravity of fine aggregate 2.65
Relative density of superplasticizer 1.1 kg/l
Water absorption of coarse aggregate 0.5%
Water absorption of fine aggregate 1%

3.2.3 Design for 1m3 Batch (0% silica replacement)
Target Strength of Mix Design
Target mean strength, F_ck = f_ck + 1.65?
Where f_ck = 70 MPa & ? = 5 (for M30 and above as per IS 10262:2009)
F_ck = 78.25 MPa

From table 2 of IS 10262:2009 21 as shown below

Table 3.1. Maximum Water content per cubic metre of
concrete for Nominal Maximum size of Aggregate
S. No. Nominal max. size of aggregate (mm) Maximum water content (kg)
1. 10 208
2. 20 186
3. 30 165

Maximum water content for 20mm aggregates = 186kg (for 25 to 50 mm slump)
For slump of 75mm, water content = 186 + ((15/100) *186) = 186 + 27.9 = 214 kg/m3
As super plasticizer is used water content can be reduced up to 30%. Therefore,
The arrived water content = 0.7*214 = 150 kg/m3
Adopted water-cement ratio = 0.28
Cementitious content = 150/0.28 = 536 kg/m3
OPC content = 536 kg/m3
Note: In order to avoid high heat of hydration for cement content above 450 ?Kg/m?^3, proper curing methods should be used in order to avoid cracks and shrinkage and maintain durability requirements.
From table 3 of IS 10262:2009 as shown below
Table 3.2 Volume of coarse aggregate per unit volume of total aggregate
for different zones of fine aggregate.
S. No Nominal max. size of aggregate (mm) Volume of coarse aggregate per unit volume of total aggregate for different zones of fine aggregate
Zone I Zone II Zone III Zone IV
1. 10 0.5 0.48 0.46 0.44
2. 20 0.66 0.64 0.62 0.60
3. 40 0.75 0.73 0.71 0.69

Volume of coarse aggregate = 0.62
For pumpable concrete these values can be reduced by 10%
Volume of coarse aggregate = 0.62*0.9 = 0.56
Volume of fine aggregate = 1-0.56 = 0.44
3.2.3.1 Mix Calculation
Volume of concrete = 1 m3
Volume of cement = 536/ (3.15*1000) = 0.1701 m3
Volume of water = 150/ (1000) = 0.15 m3
Volume of superplasticizer = 10 ml for 1kg = 5360 ml for 536kg = 0.00536 m3
Volume of all in one aggregate = 1 – (0.1701+0.15+0.00536) = 0.6745 m3
Mass of 20 mm coarse aggregate = 0.6745*0.56*2.7*1000 = 1020 kg/m3
Mass of fine aggregate = 0.6745*0.44*2.65*1000 = 786.47 kg/m3
Cement: FA: CA is 1: 1.47: 1.9

Trial Mix Proportion
Table 3.3 Mix Proportion for 0% silica Replacement
For 0% silica replacement
For 1 m3 concrete For 1 cube (0.15*0.15*0.15 m3)
Cement 536 kg 1.81 kg
Water 150 kg 0.506 kg
Coarse aggregate 1020 kg 3.44 kg
Fine aggregate 786.47 kg 2.65 kg
Superplasticizer 5.36 lt. 18.1 ml
Water cement ratio 0.28 0.28

3.2.4 Design for 1m3 Batch (10% silica replacement)
Target Strength of Mix Design
Target mean strength, F_ck = f_ck + 1.65?
Where f_ck = 70 MPa & ? = 5 (for M30 and above as per IS 10262:2009)
F_ck = 78.25 MPa
From table 2 of IS 10262:2009
Maximum water content for 20mm aggregates = 186kg (for 25 to 50 mm slump)
For slump of 75mm, water content = 186 + ((15/100) *186) = 186 + 27.9 = 214 kg/m3
As super plasticizer is used water content can be reduced up to 30%. Therefore,
The arrived water content = 0.7*214 = 150 kg/m3
Adopted water-cement ratio = 0.28
Cementitious content = 150/0.28 = 536 kg/m3
OPC content = 0.9*536 = 482.4 kg/m3
Content of silica fume = 0.1*536 = 53.6 kg/m3
Note: In order to avoid high heat of hydration for cement content above 450 ?Kg/m?^3, proper curing methods should be used in order to avoid cracks and shrinkage and maintain durability requirements.
From table 3 of IS 10262:2009, volume of coarse aggregate = 0.62
For pumpable concrete these values can be reduced by 10%
Volume of coarse aggregate = 0.62*0.9 = 0.56
Volume of fine aggregate = 1-0.56 = 0.44
3.2.4.1 Mix Calculation
Volume of concrete = 1 m3
Volume of cement = 482.4/ (3.15*1000) = 0.1532 m3
Volume of silica fume = 53.6/ (2.2*1000) = .0244 m3
Volume of water = 150/ (1000) = 0.15 m3
Volume of superplasticizer = 10 ml for 1kg = 4824 ml for 482.4kg = 0.0044824 m3
Volume of all in one aggregate = 1 – (0.1532+0.0244+0.15+0.004824) = 0.6676 m3
Mass of 20 mm coarse aggregate = 0.6676*0.56*2.7*1000 = 1009.4 kg/m3
Mass of fine aggregate = 0.6676*0.44*2.65*1000 = 778.4 kg/m3
Cement: FA: CA is 1: 1.61: 2.08
3.2.4.2 Trial Mix Proportion
Table 3.4 Mix Proportion for 10% Silica Replacement
For 10% silica replacement
For 1 m3 concrete For 1 cube (0.15*0.15*0.15 m3)
Cement 482.4 kg 1.63 kg
Water 150 kg 0.506 kg
Coarse aggregate 1009.4 kg 3.407 kg
Fine aggregate 778.42 kg 2.63 kg
Silica fume 53.6 kg 0.181 kg
Superplasticizer 4.824 lt. 16.3 ml
Water cement ratio 0.28 0.28

3.2.5 Design for 1m3 Batch (15% silica replacement)
Target Strength of Mix Design
Target mean strength, F_ck = f_ck + 1.65?
Where f_ck = 70 MPa & ? = 5 (for M30 and above as per IS 10262:2009)
F_ck = 78.25 MPa
From table 2 of IS 10262:2009
Maximum water content for 20mm aggregates = 186kg (for 25 to 50 mm slump)
For slump of 75mm, water content = 186 + ((15/100) *186) = 186 + 27.9 = 214 kg/m3
As super plasticizer is used water content can be reduced up to 30%. Therefore,
The arrived water content = 0.7*214 = 150 kg/m3
Adopted water-cement ratio = 0.28
Cementitious content = 150/0.28 = 536 kg/m3
OPC content = 0.85*536 = 455.6 kg/m3
Content of silica fume = 0.15*536 = 80.4 kg/m3
Note: In order to avoid high heat of hydration for cement content above 450 ?Kg/m?^3, proper curing methods should be used in order to avoid cracks and shrinkage and maintain durability requirements.
From table 3 of IS 10262:2009, volume of coarse aggregate = 0.62
For pumpable concrete these values can be reduced by 10%
Volume of coarse aggregate = 0.62*0.9 = 0.56
Volume of fine aggregate = 1-0.56 = 0.44
3.2.5.1 Mix Calculation
Volume of concrete = 1 m3
Volume of cement = 455.6/ (3.15*1000) = 0.1446 m3
Volume of silica fume = 80.4/ (2.2*1000) = .0365 m3
Volume of water = 150/ (1000) = 0.15 m3
Volume of superplasticizer = 10 ml for 1kg = 4556 ml for 455.6 kg = 0.004556 m3
Volume of all in one aggregate = 1 – (0.1446+0.0365+0.15+0.004556) = 0.6643 m3
Mass of 20 mm coarse aggregate = 0.6643*0.56*2.7*1000 = 1004.4 kg/m3
Mass of fine aggregate = 0.6643*0.44*2.65*1000 = 774.57 kg/m3
Cement: FA: CA is 1: 1.7: 2.2

3.2.5.2 Trial Mix Proportion
Table 3.5 Mix Proportion for 15% Silica Replacement
For 15% silica replacement
For 1 m3 concrete For 1 cube (0.15*0.15*0.15 m3)
Cement 455.6 kg 1.54 kg
Water 150 kg 0.506 kg
Coarse aggregate 1004.4 kg 3.39 kg
Fine aggregate 774.57 kg 2.614 kg
Silica fume 80.4 kg 0.271 kg
Superplasticizer 4.556 lt. 15.4 ml
Water cement ratio 0.28 0.28

3.2.6 Design for 1m3 Batch (20% silica replacement)
Target Strength of Mix Design
Target mean strength, F_ck = f_ck + 1.65?
Where f_ck = 70 MPa & ? = 5 (for M30 and above as per IS 10262:2009)
F_ck = 78.25 MPa
From table 2 of IS 10262:2009
Maximum water content for 20mm aggregates = 186kg (for 25 to 50 mm slump)
For slump of 75mm, water content = 186 + ((15/100) *186) = 186 + 27.9 = 214 kg/m3
As super plasticizer is used water content can be reduced up to 30%. Therefore,
The arrived water content = 0.7*214 = 150 kg/m3
Adopted water-cement ratio = 0.28
Cementitious content = 150/0.28 = 536 kg/m3
OPC content = 0.8*536 = 430 kg/m3
Content of silica fume = 0.2*536 = 106 kg/m3
From table 3 of IS 10262:2009, volume of coarse aggregate = 0.62
For pumpable concrete these values can be reduced by 10%
Volume of coarse aggregate = 0.62*0.9 = 0.56
Volume of fine aggregate = 1-0.56 = 0.44
3.2.6.1 Mix Calculation
Volume of concrete = 1 m3
Volume of cement = 430/ (3.15*1000) = 0.1365 m3
Volume of silica fume = 106/ (2.2*1000) = .0482 m3
Volume of water = 150/ (1000) = 0.15 m3
Volume of superplasticizer = 10 ml for 1kg = 4300 ml for 430kg = 0.0043 m3
Volume of all in one aggregate = 1 – (0.1365+0.0482+0.15+0.0043) = 0.661 m3
Mass of 20 mm coarse aggregate = 0.661*0.56*2.7*1000 = 999.4 kg/m3
Mass of fine aggregate = 0.661*0.44*2.65*1000 = 771 kg/m3
Cement: FA: CA is 1: 1.8: 2.33
3.2.6.2 Trial Mix Proportion
Table 3.6 Mix Proportion for 20% Silica Replacement
For 20% silica replacement
For 1 m3 concrete For 1 cube (0.15*0.15*0.15 m3)
Cement 430 kg 1.45 kg
Water 150 kg 0.506 kg
Coarse aggregate 999.4 kg 3.373 kg
Fine aggregate 771 kg 2.6 kg
Silica fume 106 kg 0.358 kg
Superplasticizer 4.3 lt. 14.5 ml
Water cement ratio 0.28 0.28

CHAPTER 4
EXPERIMENTAL PROCEDURES
4.1 Cement
Ordinary Portland cement of 43 grade IS: 12269-1987, Specifications for 43 Grade Ordinary Portland cement 22 has been used in this study. It was procured from a single source and stored as per IS: 4032-1977. Care has been taken to ensure that the cement of same company and same grade is used throughout the investigation. The cement thus procured was tested for physical properties in accordance with the IS: 12269-1987.
Table 4.1 Properties of ordinary Portland Cement(OPC).
S.no. Property Test method Test Results IS: 8112-1989
1. Normal Consistency Vicat’s apparatus
2. Specific Gravity Le chatelier’s flask 3.15
3. Initial setting time Vicat’s apparatus 105 minutes Not less than 30 minutes
Final setting time 165 minutes Not more than 600 minutes

4.2 Coarse aggregates and Fine aggregates
The fine aggregate used was locally available sand without any organic impurities and conforming to IS: 383-2016 23. The fine aggregate was tested for its physical requirements such as gradation, fineness modulus, specific gravity and bulk density in accordance with IS: 2386-1963.
The coarse aggregate chosen for high performance concrete was typically round in shape, well graded and smaller in maximum size than that used for conventional concrete. The size of coarse aggregate used in high performance concrete was between 10mm to 20mm using sieve analysis. The rounded and smaller aggregate particles provide better flow ability and deformability of concrete and also prevent segregation. Graded aggregate is also important particularly to cast concrete in highly congested reinforcement or formwork having small dimensions. The physical properties like specific gravity, bulk density, flakiness index, and elongation index and fineness modulus were tested for the coarse aggregates.
Table 4.2. Properties of fine aggregate and coarse aggregate.
S.no. Property Method Fine Aggregate Coarse aggregate
1. Specific gravity Pycnometer 2.65 2.7
2. Flakiness index Test gauges – 6%
3. Elongation index Test gauges – 8%
4. Fineness modulus Sieve analysis 3.89 6.94
5. Moisture content Oven drying test 1% 0.5%
6. Toughness Impact value test – 17%

4.2.1 Sieve Analysis (IS 383:2016)
Table 4.3 Sieve Analysis for Fine Aggregates
Sieve size (mm) Wt. retained (gm.) Cumulative wt. retained (gm.) Cumulative % retained Cumulative % passing Permissible limit
10 0 0 0 100 100
4.75 196.5 196.5 7.86 92.14 90 to 100
2.36 215.25 411.75 16.47 83.53 75 to 100
1.18 551.5 963.25 38.53 61.47 55 to 90
600 microns 228 1191.25 47.65 52.35 35 to 59
300 microns 897.5 2088.75 83.55 16.45 8 to 30
150 microns 292.25 2381 95.24 4.76 0 to 10
Pan 119 2500 100 0 0

Table 4.4 Sieve Analysis for Coarse Aggregates
Sieve size (mm) Wt. retained (gm.) Cumulative wt. retained (gm.) Cumulative % retained Cumulative % passing Permissible limit
40 0 0 0 100 100
20 445.5 445.5 8.91 91.09 85-100
10 4397 4842.5 93.85 6.15 0-20
4.75 125.5 4968 99.36 0.64 0-5
pan 32 5000 100 0 0

4.3 Water
Water used for mixing and curing was potable water, which was free from any amounts of oils, acids, alkalis, sugar, salts and organic materials or other substances that may be deleterious to concrete or steel confirming to IS: 3025-1964 Part 22, Part 23 24 and IS: 456-200025. The pH value should not be less than 6.

4.4 Super plasticizer (PLASTIMENT 2001NS)
High range water reducing admixture called as super plasticizers are used for improving the flow or workability for lower water-cement ratios without sacrifice in the compressive strength. These admixtures when they disperse in cement agglomerates significantly decrease the viscosity of the paste by forming a thin film around the cement particles. In the present work, water-reducing admixture PLASTIMENT 2001 NS conforming to IS 9103-1999 26, IS 2645 is used. Super plasticiser is used as 1000ml per 100kg of cement i.e., 1% in this project.

Table 4.4 Super Plasticizer Description.
S.NO
1. Product description A liquid mid-range water-reducing cum water proofing concrete admixture with a powerful plasticizing effect. Also, a substantial water reduction can be attained to promote high ultimate strengths at the high dosage range.
2. Approval standard IS 9103-1999, IS 2645
3. Appearance Brown liquid
4. Chemical base Modified lingo sulphonate
5. Relative density 1.1 kg/l at 25o C
6. Dosage 0.5% to 2.0% by weight of cement. Higher dosage may be used if agreed by engineer and consultant.
Actual dosage to be finalised on the basis of site trials

4.5 Batching and mixing
To avoid confusion and error in batching, consideration should be given to using the smallest practical number of different concrete mixes on any site or in anyone plant. In batching concrete, the quantity of both cement and aggregate shall be determined by mass admixture (if solid, by mass and liquid admixture may however be measured in volume or mass) water shall be weighed or measured by volume in a calibrated tank.
Proportion/type and grading of aggregate shall be made by trial in such a way so as to obtain densest possible concrete. All ingredients of the concrete should be used by mass only. The mixing process is carried out in electrically operated concrete mixer and should comply with IS 1791 and IS 12119. The materials are laid in uniform layers, one on the other in the order – coarse aggregate, fine aggregate and cementitious material. Dry mixing is done to obtain a uniform colour. The silica fume is thoroughly blended with cement before mixing.
The slump test was carried out in accordance with IS: 1199-1959 27 and for the concreting of cubes, slump was maintained in the collapsible range of 75-100mm.
Dosage of retarders, plasticizers and super plasticizers shall be restricted to 0.5, 1.0 and 2.0 percent respectively by weight of cementitious material and unless a higher value is agreed upon between the manufacturer and the constructor based on performance test.

Fig. 4.1 Dry mix ingredients

Fig. 4.2 Cubes in Mould

4.6 Curing of concrete cubes
Curing is the process of preventing the loss of moisture from the concrete whilst maintaining a satisfactory temperature regime. The prevention of moisture loss from the concrete is particularly important if the water cement ratio is low, if the cement has a high rate of strength development, if the concrete contains granulated blast furnace slag or pulverised fuel ash. The curing regime should also prevent the development of high temperature gradients within the concrete. The rate of strength development at early ages of concrete made with super sulphated cement is significantly reduced at” lower temperatures. Super sulphated cement concrete is seriously affected by inadequate curing and the surface has to be kept moist for at least seven days.
The rate of strength of development at early ages of concrete made with super sulphated cement is significantly reduced at lower temperatures. Super sulphated cement concrete is seriously affected by inadequate curing and the surface has to be kept moist for at least seven days.

Fig. 4.3 Curing of cubes
4.7 Compressive strength test (IS 516-1959)
It gives an overall idea about the strength of concrete. Concrete compressive strength for general construction varies from 15 MPa to 30 MPa and higher grades in commercial and industrial structures. Compressive strength depends on many factors such as water cement ratio, cement grade, aggregates quality and quality control during production of the concrete. Test for concrete strength is carried our either on cube or cylinder and the procedure adopted should be in accordance with IS 516-1959.

Fig. 4.4 Casted Cubes

Fig. 4.5 Weighing of Cube
The testing machine may be of any reliable type of sufficient capacity and capable of applying the load at the rate of 140 kg/m2. The testing machine should be equipped with two steel bearing platens with hardened face. At least three specimens preferably from different batches shall be made for testing the specimen. There are two types of specimen of 15cm sided cube or 10 cm sided cube are used for the compression tests. For most of the work cubical moulds of size 15cmX15cmX15cm are commonly used. The concrete is poured in the mould with prior lubrication of the mould and put in 3 layers with 25 blows of tamping rod at each layer. The top surface of these specimen should be made even and smooth that can be done by putting cement paste and spreading smoothly on whole area of the specimen. After 24 hours of drying the moulds are removed and concrete specimens are put in water tank for curing. Tests shall be made at recognized ages of the specimen the most usual being 7 days and 28 days according to IS 516-1959. The ages of specimen shall be calculated from the time of addition of water in the dry ingredients.

Fig. 4.6 Compression Testing Machine
The measured compressive strength of the specimen shall be calculated by dividing the maximum load applied to the specimen during the test by the cross-sectional area calculated from the mean dimensions of the section and shall be expressed to the nearest kg per sq. cm. Average of three values shall be taken as the representative of the batch provided the individual variation is not more than 15% (+ & -) of the average otherwise repeat tests shall be made.

CHAPTER 5
RESULTS AND DISCUSSIONS
5.1 Results of Compression Strength Test
Test specimens of size 15cmX15cmX15cm were prepared for testing the compressive strength concrete. The concrete mixes with varying percentages (0%, 10%, 15% and 20%) of silica fume as partial replacement of cement were cast into cubes and cylinders for subsequent testing. In this study, to make concrete, cement and fine aggregate were first mixed dry to uniform colour and then coarse aggregate was added and mixed with the mixture of cement and fine aggregates. Water was then added and the whole mass mixed. The interior surface of the moulds and the base plate were oiled before concrete was placed.
After 24 hours the specimens were removed from the moulds and placed in clean fresh water at a temperature of 270 C. The specimens so cast were tested after 7 and 28 days of curing measured from the time water is added to the dry mix. For testing in compression, no cushioning material was placed between the specimen and the plates of the machine. The load was applied axially without shock till the specimen was crushed.
The cube strength results of concrete mix are also shown graphically in Figure 5.2 and 5.4. The compressive strength increases as compared to control mix as the percentage of silica fume is increased. As we increase the percentage of silica fume its compressive strength increases continuously from 0% to 10% respectively and after 15% its start decreasing. Figure 5.1 and 5.3 shows the variation of percentage increase in compressive strength with replacement percentage of silica fume. The results also indicate that early age strength gain i.e. at 7 and 28 days, is higher when compared to the control mix if 15% of cement is replaced by silica fume.

5.1.1 Compressive Strength after 7 days
Results of the compressive strength test on concrete with varying proportions of silica fume replacement at the age of 7 days are given in the Table 5.1 as shown below.
Table 5.1. 7th day Compressive strength
S.no. Silica fume replacement
(in %) Specimen Applied load
(KN) Compressive strength
(?N/mm?^2) Average compressive strength
(?N/mm?^2)
1. 0 % 1st
2nd
3rd 870
953
867 38.67
42.35
38.53
39.85
2. 10 % 1st
2nd
3rd 962
1032
998 42.75
45.87
44.35
44.32
3. 15 % 1st
2nd
3rd 1068
984
1040 47.47
43.73
46.22
45.81
4. 20 % 1st
2nd
3rd 964
1002
942 42.84
44.53
41.87
43.08

5.1.2 Compressive Strength after 28 days
Results of the compressive strength test on concrete with varying proportions of silica fume replacement at the age 28 days are given in the Table 5.2 as shown below.
Table 5.2. 28th day compressive strength
S.no. Silica fume replacement
(in %) Specimen Applied load
(KN) Compressive strength
(?N/mm?^2) Average compressive strength
(?N/mm?^2)
1. 0 % 1st
2nd
3rd 1439
1370
1339 63.95
60.88
59.51
61.44
2. 10 % 1st
2nd
3rd 1525
1544
1513 67.78
68.62
67.24
67.88
3. 15 % 1st
2nd
3rd 1546
1594
1567 68.71
70.84
69.64
69.73
4. 20 % 1st
2nd
3rd 1488
1516
1483 66.13
67.37
65.91
66.47

Fig. 5.5 Comparison of Cube’s strength according to days

5.2 Discussions
After adding silica fume with varying percentages of 0%, 10%, 15% and 20% in the mix, there is an increase in the strength of cube from 0% to 15% and a decrease thereafter. It shows that we can replace silica fume only up to an extent, since after that problems of high heat hydration, shrinkage and crack at a particular water cement ratio involves.
On addition of silica fume in concrete, initially it remains in inert condition. Once cement and water in the mix start reacting with each other (hydration), primary chemical reactions produce two chemical compounds: Calcium Silicate Hydrate (CSH), which is responsible for strength, and Calcium Hydroxide (CaOH2), a by-product also called free lime which is responsible for filling available pores within concrete as a filler or leaching out of inferior concrete.
Pozzolanic reaction occurs between silica fume and the CaOH2, producing additional CSH in many of the voids around hydrated cement particles. This additional CSH provides the concrete with improved compressive strength but also a denser concrete mix.

CHAPTER 6
CONCLUSION
The Objective of this project was to study about the High-Performance Concrete and achieve a high strength concrete of grade equivalent to M70. In the process we were able to achieve maximum strength of 69.73 MPa after a series of trial mixes being prepared and tested.
The desire concentration of silica fume as replacement was observed as 15% in this project.
The compressive strength enhancement that we have attained using the optimum percentage of silica fume as replacement stands at satisfying 13.3%.
During working on this project, we were able to understood various aspects of quality control for design mix of higher grade and various uncertainties associated with concrete mix. It is quite clear that even smaller or minor things can be crucial and may affect the behaviour of concrete especially for grade above M50.

REFERENCES
1 Nishant Rana, Abhishek Tiwari and Alok Kumar Srivastava: International Journal of Current Engineering and Technology, Vol.6, No.3 (June 2016):982
2 Henry G. Russell: Publication: Concrete International, American Concrete Institute(ACI): Volume No: 21: Issue No: 2: 56-57
3 International Journal of Current Engineering and Technology, Vol.6, No.3 (June 2016): 984-985
4 Modern Concrete Technology: High-Performance Concrete: P.C. Aitcin
5 American Concrete Institute: Concrete International: Volume No: 26: Issue No: 5: 454-456
6 Ozawa et al. (1990), M Ouchi, H Okamura: Concrete international: Volume No: 32: Issue No: 3: 856-857
7 Mehta and Aitcin (1990): Concrete international: Volume No: 34: Issue No: 3: 897-898
8 Aitcin and Neville (1993): American Ceramic Society. 22:286-290: Volume No: 44: Issue No: 6: 814-816
9 Forster (1994): High-Performance Concrete Journal: International Journal of Civil Engineering and Technology: Volume No: 74: Issue No: 5: 234-236
10 The Federal Highway Administration (FHWA) Bridges and other structures: Volume No: 93: Issue No: 6: 354-356
11 Nima Farzadni et al. (2011): Concrete International: Volume No: 61: Issue No: 2: 534-536
12 Tsong Yen (1999): International Journal of Civil Engineering and Technology, Vol.6, No.3: 1223-1225
13 Bushlaibi (2004): Journal on High-Performance Concrete: Volume No: 45: Issue No: 2: 745-747
14 Debabratha and Dutta (2013): Study of the influence of silica fume on normal concrete with replacement of cement by silica fume: Volume No: 135: Issue No: 2: 1025-1027
15 Fu et al., (1998) Study on bond strength between concrete, steel rebar using silica fume: Volume No: 76: Issue No: 9: 232-234
16 Mostofinejad and Nozhati (2005): Modulus of elasticity of high strength concrete based on characteristics of the concrete mix: Volume No: 76: Issue No: 13: 293-295
17 Cusson and Margeson (2010): Durability characteristics of High-Performance Concrete: Volume No: 26: Issue No: 45: 732-734
18 Knab and Clifton (1982): Study on the methods of measuring the cumulative damage of steel reinforced concrete slabs subjected to repeated impact: Volume No: 146: Issue No: 35: 64-66
19 Vagelis (2000): Durability of cement incorporating cementing materials silica fume, low-and high-calcium fly ash (SCM): Volume No: 86: Issue No: 15: 32-34
20 Franklin (1976): Study on Superplasticisers and their characteristics: Volume No: 2: Issue No: 105: 653-655
21 Indian Standard 10262:2009: Concrete Mix Proportioning – Guidelines (First Revision)
22 Indian Standard 12269:1987: Specification for 53 Grade Ordinary Portland Cement (First Revision)
23 Indian Standard 383:2016: Specification for coarse and fine aggregate for Concrete (Third Revision)
24 Indian Standard 3025:1965 Part 23: Methods of Sampling and Test (Physical and Chemical) For Water and Wastewater
25 Indian Standard 456:2000: Plain and Reinforced Concrete Code of Practice
26 Indian Standard 9103:1999: Specification for Concrete Admixtures.
27 Indian Standard 1199:1959: Methods of sampling and Analysis of concrete
28 Indian Standard 516:1959: Methods of Tests for Strength of Concrete