CHAPTER-1INTRODUCTION 1.1 GENERALCement concrete is the most extensively used construction material in the world. The reason for its extensive use is that it provides good workability and can be moulded to any shape. Ordinary cement concrete possesses a very low tensile strength, limited ductility and little resistance to cracking. Internal micro cracks, leading to brittle failure of concrete. In this era, civil engineering constructions have its own requirements such as strength and durability. Every structure is constructed to full fill the requirement and hence to meet this purpose, modification in traditional cement concrete has become important and mandatory.
Waste utilization is an attractive alternative to disposal in that disposal cost and potential pollution problems are reduced or even eliminated along with the achievement of resource conservation. Nevertheless, the utilization strategy must be coupled with environmental and energy considerations to use available materials most efficiently. Steel slag, the by-product of steel and iron producing processes, started to be used in civil engineering projects during the past 12 years. The second waste from steel is the iron filing, which is produced locally in great amounts from steel workshops and factories. This product has a negative impact on the environment when disposed from this reason the research project started. Thus using the lathe scrap as an alternative in concrete can be examined.
1.2 CONCRETE . . . Concrete is a composite material composed of coarse aggregate bonded with cement and fine aggregate. The cement is used to bind all material together and hardened with time, when aggregate is mixed together with dry Portland cement of water. The mixture form slurry, which can be early poured, anywhere and moulded into any shape. The coarse aggregate which is used in concrete is consist of large chunks of materials in a concrete mix, generally a coarse gravel or crushed rocks such as lime stone or granite. Chemical admixtures are use to achieve its properties. These admixture may slow down the rate of hardness of concrete. The reinforcement is also used in concrete to improve the tensile strength of concrete, as concrete is good in compression and bad in tension.
1.3 MOTIVATIONScrap from lathe machine is produced from different manufacturing processes which are carried out by lathe machine. Scrap which is a waste can be used as an reinforcing material in concrete to enhance the various properties of concrete. Scrap from machine can act in a same way as steel fiber. Steel scrap which is a lathe waste is generated by each lathe industry and dumping of such wastes in barren soil causes contamination of soil and ground water, which creates unhealthy environment. In addition to get sustainable development and environmental benefits, lathe scrap can be used as recycled fiber with concrete. With increase in population and industrial activities, the quantity of waste fibers generated will increase in coming years. These industrial waste fibers can be effectively used for making high-strength low cost FRC after exploring their suitability. Plain reinforced concrete is brittle material due to addition of steel fibers in concrete considerably increases the tensile strength, static flexural strength, durability ,impact strength and shock resistance. Concrete is a material which is weak in tension and fails in brittle manner when subjected to tension and flexure. When steel scrap is added to concrete, the behavior of composite material is superior to plane concrete. A good waste solid management is to find a way to make use of it. In this paper an experimental investigation was carried out to study the feasibility of using steel scrap obtained from lathe machine in concrete by checking the compressive strength, splitting tensile strength and flexural strength of M20 concrete and thus optimizing the fiber proportions. Lathe steel scrap reinforced concrete (LSSRC) is a cost effective replacement for fiber reinforced concrete.
To explore and study the use of lathe scraps as fiber in concrete.
To compare proportions and percentages of lathe fibers in concrete and study their effects.
Effect of use of Steel Scrap on workability.
Effect on Compression Strength of concrete by using lathe scrap of various size.
Effect on Tensile Strength of concrete using lathe scrap of various size.
Effect of micro cracks using lathe Scrap.
1. 5 SCOPEWhen we speak of compressive strength of concrete, it is quite high but tensile strength becomes low. When we use steel reinforcement the tensile strength of concrete increases considerably. Research followed by technological developments have enlightened us with ways to add fiber to strengthen concrete. To develop specialized concrete lots of efforts are being in this field. Attempts are being made by worldwide researchers to effectively enhance the performance of concrete by using admixtures and fibers in certain proportions. Recently we have begun using lathe waste material that is locally available which has become an important part in construction. Fiber reinforced concrete usage has been amplified by the day particularly due to the introduction of steel fiber to cement concrete which has led to an incredible improvement in usability properties of concrete. One ton of carbon dioxide is released into the atmosphere by the production of a single ton of cement. Similar damage to the environment is done by the steel industry. To avoid such staggering quantities of generated wastes we need to reuse it by pondering over sustainable development. At present, we are faced with expensive options in the market when it comes to purchase of different categories of steel fiber. Lots of local workshops and lathes offer low cost lathe scraps in plentitude. Lathe industries generate daily approximately 20 kg lathe waste and heavily contaminate the ground water and soil by dumping in the barren lands. Effective management of waste steel scrap material derived from lathe to be used as steel fiber is among the finest solutions for civil construction like pavements and other structures this recycles the lathe scrap with concrete. The objective of this paper is to do a comparative study of plain concrete and lathe fiber reinforced concrete. Research followed by experiments and investigations are inevitably necessary to learn details of both plain and steel fiber reinforced concrete when they are fresh and hardened respectively. Various improvements in properties are noted by the addition of fiber such as crack resistance and prevention of crack
propagation, modulus of elasticity, shrinkage reduction and toughness.
1.6 METHODOLOGYConcrete is strong in compression and weak in tension and also it has brittle character. The concept of using steel scrap concrete is to improve the characteristic strength of construction material. Use of steel scrap in concrete increases the strength and ductility, but requires careful placement and labour skill. Internal micro cracks, leads to the brittle failure of concrete.
It is observed that one of the important properties of Steel Scrap Concrete is its superior resistance to cracking and crack propagation. Thus the concrete is reinforced with the steel scrap in various proportions such as 0%, 0.5%, 1.0%, 1.5%, 2%, 2.5% and 3% by weight of cement of size 20mm. The Compressive and Tensile Strength were analysed as per IS standards on 7th, 14th and 28th day of curing.
1.7 ORGANIZATION OF THESIS
CHAPTER 1. INTRODUCTION
The property of concrete is that concrete is weak in tension and strong in compression. The concept of using steel scrap in concrete improves the properties of concrete. In Earlier days the application of steel scrap includes the addition of straw to the mud bricks, horse hair to reinforce plaster. Use of randomly steel scrap in concrete increases strength and ductility, but casting of concrete requires attention. According to many researchers, the addition of steel scrap into concrete reduces the workability of concrete. Therefore to solve this problem super-plasticizer is added, without affecting other properties of concrete. Fiber reinforced concrete reinforced with more or less randomly distributed fibers. It has been successfully used in construction during its excellent flexural-tensile strength, resistance to spitting, impact resistance and excellent permeability and frost resistance. It is an effective way to increase toughness, shock resistance and resistance to plastic shrinkage cracking of the concrete. Steel Fiber in concrete improves ductility and its load carrying capacity. The mechanical properties of steel fiber reinforced concrete are much improved by the use of hooked fibers than straight fibers.
CHAPTER 2. LITERATURE REVIEW
In today’s technologically advanced world we can find concrete very easily at lower costs compared to before. It is one of the most adaptable and flexible building materials available which can be molded to fit into any column or rectangular beam as well as a cylindrical tank of water storage. High rise buildings and any structural shapes from the ordinary to the extraordinary can be built. The need for reinforcing concrete is due to the weak tensile strength even though under compression concrete is very strong. Hence, we use many forms of reinforcement; the most common being steel bars. As with every boon of modern civilization we must deal with the pros and cons of concrete too. Some of the disadvantages are low tensile strength and formwork requirement. Its primary benefits are its high water and fire resistance and compressive strength with a very good service life and low maintenance. Concrete has its drawback in relatively low strength per unit weight.
Concrete?s tensile strength is characteristically 8-15% of its compressive strength. This limitation has been dealt with by engineers in recent and past times by utilizing rebar?s (reinforcing bars) to create reinforced concrete. The purpose of this is to benefit from the resistance that rebar?s have over tensile and shear stresses and the resistance of concrete over compressive stresses. A beam has a longitudinal rebar which resists flexure (tensile stress) while the stirrups enveloping the longitudinal bar hold the bar in position in addition to resisting shear stresses. When we speak of vertical bars in a column, they are resistant to buckling and compression stresses while the ties provide confinement to vertical bars along with resisting shear. Reinforced concrete structures are susceptible to cracks which flow freely until they meet a rebar. Therefore, we need closely paced tightly held reinforced concrete which should also be multidirectional.
CHAPTER 3: TESTING
The testing of concrete is performed on steel fibre reinforced concrete to improve the tensile strength as well as compressive strength of concrete. Before testing of concrete the ingredients like cement and aggregate are tested. Then the compressive and tensile strength were determined as per IS: 516-1959 and IS: 516-1999 respectively on 7th day, 14th day and 28th day with water cement ratio 0.5. The strength property of concrete reinforced with steel fibre of various sizes were analysed
CHAPTER 4: RESULT AND ANALYSIS
Testing of fresh and hardened concrete is performed and analysed as per Indian standard procedure. The performance of Steel reinforced concrete in various proportions such as 0%, 0.5%, 1%, 1.5%, 2%, 2.5% and 3% with size of 20mm was examined. These ratios will give good compressive strength as compare to normal concrete and also improves its tensile strength also. The comparison between normal concrete, quarry dust replacing sand concrete, and replacing sand concrete with fiber to generate a good cohesion with other aggregates which enhances mechanical properties of the concrete.
CHAPTER 5: CONCLUSION
Also, it has been observed that with the increase in fiber content increases the strength of concrete. The tensile strength of concrete increases effectively. The micro and macro cracks can be reduced by using Steel fibre reinforced concrete. Slump cone test was adopted to measure the workability of concrete. The Slump cone test results revealed that workability gets reduced with the increase in fiber content.
Chapter 2LITERATURE REVIEW2.1 GENERAL
Concrete is most widely used construction material in the world due to its ability to get cast in any form and shape. It also replaces old construction materials such as brick and stone masonry. The strength and durability of concrete can be changed by making appropriate changes in its ingredients like cemetitious material, aggregate and water and by adding some special ingredients. The presence of micro cracks in the mortar-aggregate interface is responsible for the inherent weakness of plain concrete. The weakness can be removed by inclusion of fibres in the mixture. Different types of fibers, such as those used in traditional composite materials can be introduced into the concrete mixture to increase its toughness, or ability to resist crack growth. The fibres help to transfer loads at the internal micro cracks.2.2 FIBRE REINFORCED CONCRETE
Fibre reinforced concrete (FRC) is Portland cement concrete reinforced with more or less randomly distributed fibres. In FRC, thousands of small fibres are dispersed and distributed randomly in the concrete during mixing, and thus improve concrete properties in all directions. The development of fiber reinforced cement concrete is undergoing in recent year. Fiber reinforced concrete is successfully used in constructions with its excellent properties of compression-tensile strength, crack resistance and impact resistance. It is an effective way from which we can increase the properties of concrete such as toughness, shock resistance and resistance to plastic shrinkage cracking of the mortar. They can be circular, triangular or flat in cross-section. The fire is often described by a convenient parameter called ?aspect ratio?. The aspect ratio of the fibre is the ratio of its length to its diameter. The principle reason for incorporating fibres into a cement matrix is to increase the toughness and tensile strength and improve the cracking deformation characteristics of the resultant composite.
For FRC to be a viable construction material, it must be able to compete economically with existing reinforcing system.FRC composite properties, such as crack resistance, reinforcement and increase in toughness are dependent on the mechanical properties of the fibre, bonding properties of the fibre and matrix, as well as the quantity and distribution within the matrix of the fibres.
2.3 LITERATURE REVIEW1. Sheetal Chinnu James et.al.: Fiber reinforced concrete is a concrete containing fibrous materials that are uniformly distributed and randomly oriented. The fibers include steel fiber, glass fiber, natural fiber and synthetic fiber. The waste steel scrap material which is available from the lathe can be used as steel fiber for innovative construction industry and also in pavement construction. Lathe waste is generated by each lathe industries and dumping of these wastes in the barren soil contaminates the soil and ground water, which creates an unhealthy environment. In addition to get sustainable development and environmental benefits, lathe scrap as recycled fibers with concrete are likely to be used. In this project fiber reinforced concrete using lathe waste is prepared and its fresh and hardened properties are studied. The tests conducted were slump test, compressive strength test, split tensile strength test and flexural strength test. For this concrete cubes, beams and cylinders were casted and cured and tests were done at 7th day and 28th day.
2. Abdul Rahman et.al.
This project work emphasis on the study of using steel scrap and manufacture sand in the innovative construction industry. “Steel scrap” concrete is a concrete containing fibrous material that is uniformly distributed and casually oriented. The steel scrap waste material which is obtainable from the lathe can be used as steel fiber for the innovative construction industry and in pavement construction. It is generated by each lathe industries Dumping of these wastes contaminates the soil and groundwater, which creates a harmful environment. In addition, to get sustainable development and environmental benefits, lathe scrap with concrete is likely to be used. In this project steel scrap concrete using lathe waste is prepared and its properties are studied. “Manufactured sand” is such alternative for good quality Natural River sand due to depletion of resources and restriction due to environmental consideration has made concrete manufacturers look for suitable alternative fine aggregate. Though it has been in use in concrete manufacturing in India, the percentage of its contribution is still very negligible in many parts of the country. The tests conducted were slump test, compressive strength test, split tensile strength test and. For this concrete cubes, beams and cylinders were cast and cured and tests were done at 3th day, 7th day and 28th day.
3. Pooja Shrivastavaa and Dr.Y.p. Joshi: Reuse of Lathe Waste Steel Scrap in Concrete Pavements: These project works assess on the study of the workability and mechanical strength properties of the concrete reinforced with industrialized waste fibers or the recycled fibers. In each lathe industries wastes are available in form of steel scraps are yield by the lathe machines in process of finishing of different machines parts and dumping of these wastes in the barren soil contaminating the soil and ground water that builds an unhealthy environment. Now a day’s these steel scraps as a waste products used by innovative construction industry and also in transportation and highway industry. Different experimental studies are done to identify about fresh and hardened concrete properties of steel scrap fiber reinforced concrete (SSFRC) and their mechanical properties are found to be increase due to the addition of steel scrap in concrete i.e. compressive strength, flexural strength, impact strength, fatigue strength and split tensile strength were increased but up to 0.5-2% scrap content . When compared with usual concrete to SSFRC, flexural strength increases by 40% and considerable increases in tensile and compressive strength. These steel scrap also aid to improve the shrinkage reduction, cracking resistance i.e. preventing crack propagation and modulus of elasticity.
4. Prof. Kumaran and Nithi : Effect of Lathe Waste in Concrete as Reinforcement: An Experimental investigation is carried out on the strength of lathe waste concrete and deformational behavior of lathe waste concrete beams. The waste steel scrap available from the lathe is used. Optimum combination of lathe waste is studied. For this cube and cylinder compressive strength, flexural test and split tensile strength tests were carried out. The deformational behavior was investigated with this optimum content. A total of 24 reinforced lathe waste concrete beams had been tested to investigate the influence of lathe waste and combined effect of lathe waste and stirrups on the deflection, cracking, ultimate load and failure pattern.Beams without stirrups and with stirrups are studied. The experiments have demonstrated the advantages of combining lathe waste with steel stirrups. Load- deflection behavior of simply supported beams is increased. Reinforced lathe waste concrete beams show less deformation than similar reinforced normal conventional concrete beams. The combination of lathe waste and stirrups increases the ultimate load of concrete beams. Test results indicated that the inclusion of lathe waste significantly improves the strength and deformational characteristics of concrete.
5. G Vijayakumar et.al. Impact And Energy Absorption Characteristics Of Lathe Scrap Reinforced Concrete: This project work emphasis on the study of using lathe scrap as fibre reinforced concrete in the innovative construction industry. Every day about 8 to 10 kg of lathe waste are generated by each lathe industries in the Pondicherry region and dumped in the barren soil there by contaminating the soil and ground water, which creates an environmental issue. Hence by adopting proper management by recycling the lathe scrap with concrete is considered to be one of the best solutions. The 7 days strength of the Lathe scrap reinforced concrete shows an increase in its compressive strength when compared with PCC, and almost become equal to the strength when tested on 28 days under normal curing. The addition of lathe scrap in concrete has increase the performance of beam in flexural by 40% when compared with PCC. There is only a considerable increase in the split tensile strength of concrete with lathe scrap when compared with PCC. The workability of fresh concrete that containing different ratios of lathe scrap was carried out by using slump test. The result showed that addition of lathe scrap in to PCC mixture enhanced its compressive strength while it decreased the workability of the fresh concrete containing the lathe scrap. The impact strength of concrete mixed with lathe scrap shows increased impact strength when compared with PCC.
6. Abhishek Mandloi and Dr. K. K. Pathak: Utilization of Waste Steel Scrap for Increase in Strength of Concrete-Waste Management: Due to rapid growth of population, rapidlyincreasing in industries which directly increases wastewithout any management. In this world where somecountries are developed and some are developing, theunbelievable demand of steel is on its peak, but it leadstoward a dumping ground of industrial waste. For reductionof this dumping of scrap and save the earth from thishazardous problem utilization of steel scrap in concrete isthe key step for save the environment and achievingsustainability that will enable the earth to continue to support human life. This paper presents a research to utilization of waste (CNC lathe waste) by partial replacement (5% by weight of natural coarse aggregate)with coarse aggregate. Also for the increment in strength of concrete, wire mesh is used while casting in the form of10mm3cubes.
7. Zeeshan Nissar Qureshi and Yawar Mushtaq Raina: Strength Characteristics Analysis of Concrete Reinforced With Lathe Machine Scrap: The aim of the paper was to study the feasibility of using lathe machine scrap in concrete by checking the compressive strength, splitting tensile strength, flexural strength and load deflection characteristics. All these parameters were found out by varying proportions of lathe machine by 0%, 1 %, 1.5% and 2% by weight in M20 concrete. Thus finding out optimum percentage of lathe machine scrap in concrete up to which its mechanical properties like compressive strength, splitting tensile strength, flexural strength can be increased. All the tests were conducted by following the guidelines set by Indian Standard. The compressive strength was found out to be 25.5N/mm2 , 26.8N/mm2 , 28.4N/mm2 and 23.33N/mm2 for 0%, 1 %, 1.5% and 2% lathe machine scrap reinforcement respectively. The splitting tensile strength was 2.85N/mm2 , 3.04N/mm2 , 3.37N/ mm2 and 2.94N/mm2 , where as flexural strength were 4.33N/mm2 , 5N/mm2 , 5.66N/mm2 and 4.83N/mm2 for 0%, 1 %, 1.5% and 2% lathe machine scrap reinforcement respectively. The strength properties of concrete were increasing by adding lathe machine scrap up to 1.5 % by weight in concrete after this slight reduction in strength properties of concrete was noticed. The compressive, split tensile and flexure strengths were increasing by 11.37 %, 18% and 30 % for optimum percentage of lathe machine scrap which was found to be 1.5%. The load carrying capacity of beam at same percentage of lathe machine scrap was found to be 5.66kN and deflection which was also maximum among all percentages was 7mm. Lathe machine scrap was found to be strong and environmental friendly material which can improve structural strength of concrete, decrease steel reinforcements besides, reducing width of cracks when used as reinforced material in concrete.
From the above research it is shown that the use of steel fibre reinforcement increases the strength. Many researchers had worked in steel fibre reinforced concrete in many proportions but none of them had tested by adding upto 3% of steel fibre in concrete. Thus in this thesis the work has been done by using of steel fibre reinforced concrete of Aspect Ratio 66 in various proportion such as 0.5%, 1%, 1.5%, 2%, 2.5% and 3%.
CHAPTER 3MATERIALS AND METHODOLOGY3.1 GENERAL
Concrete is relatively strong in compression but weak in tension and tends to be brittle. This weakness in tension can be overcome using lathe scrap as reinforcement. To improve the tensile strength fibers can be used in replacing lathe scrap. Thin fiber reinforced concrete makes concrete as light weight material thus inclusion of fiber in concrete as a reinforcement can be called as fiber reinforced light weight concrete. There are various fiber used as reinforcement now a day.
3.2 LATHE SCRAPE
Fig 1. Lathe scrape3.3 CEMENTCement is a binding material, a substance that sets and hardens independently, and can bind other materials together. The word “cement” derived from the Romans. Cements used in construction are of two types hydraulic or non-hydraulic. Hydraulic cements (e.g.,Portland cement) harden because of hydration, a chemical reaction between anhydrous cement powder and water. Thus they can harden underwater or when constantly exposed to wet weather. Non-hydraulic cements do not harden underwater; for example, slaked limes harden by reaction with atmospheric carbon dioxide. The uses of cement are as an ingredient of mortar in masonry, and of concrete, a combination of cement and an aggregate to form a strong building material.
3.3.1 PORTLAND CEMENTPortland cement (Ordinary Portland Cement) is the most common type of cement in general use in all over the world, used as a basic ingredient of concrete, mortar, stucco, and most non-specialty grout. It is derived from limestone. It is a fine powder produced by grinding Portland cement clinker (more than 90%), a limited amount of calcium sulphate (which controls the set time) and up to 5% minor constituents as allowed by various standards such as the European Standard EN 197-1:
Portland cement clinker is made by heating in a kiln, a homogeneous mixture of raw materials to a claiming temperature, which is about 1450°C for modern cements. The major raw material for the clinker-making is usually limestone (CaCO3) mixed with a second material containing clay as source of alumina-silicate. Normally, an impure limestone which contains clay or SiO2 is used. The CaCO3 content of this limestone’s can be as low as 80%. Secondary raw materials (materials in the raw mix other than limestone) depend on the purity of the limestone. Some of the materials used are clay, shale, sand, iron ore, bauxite, fly ash, and slag.
Table 1.Typical constituents of Portland cement
Cement CCN Mass %
Calcium oxide, CaO C 61–67%
Silicon dioxide, SiO2 S 19–23%
Aluminum oxide, Al2O3 A 2.5–6%
Ferric oxide, Fe2O3 F 0–6%
Sand is a naturally occurring granular material composed of finely divided rock and mineral particles. The second most common type of sand is calcium carbonate, for example aragonite, which has mostly been created over the past half billion years, by various forms of life, like coral and shellfish.
In terms of particle size as used by geologists, sand particles range in diameter from 0.0625 mm (or 1?16 mm) to 2 mm. An individual particle in this range size is termed a sand grain. Sand grains are between gravel (with particles ranging from 2 mm up to 64 mm) and silt (particles smaller than 0.0625 mm down to 0.004 mm). The size specification between sand and gravel has remained constant for more than a century, but particle diameters as small as 0.02 mm were considered sand under the Albert Atterberg standard in use during the early 20th century. A 1953 engineering standard published by the American Association of State Highway and Transportation Officials set the minimum sand size at 0.074 mm. A 1938 specification of the United States Department of Agriculture was 0.05 mm.
PROPERTIES OF GOOD SAND:
It should be clean and coarse.
It should be chemically inert.
It should contain sharp, angular, coarse and durable grains.
It should be strong and durable.
It should be clean and free from coatings of clay and silt.
Aggregates are the most mined materials in the world. Aggregates are a component of concrete and asphalt concrete; the aggregate serves as reinforcement to add strength to the overall composite material. Due to the relatively high hydraulic conductivity value as compared to most soils, aggregates are widely used in drainage applications such as foundation and French drains, septic drain fields, retaining wall drains, and road side edge drains. Aggregates are also used as base material under foundations, roads, and railroads. In other words, aggregates are used as a stable foundation or road/rail base with predictable, uniform properties (e.g. to help prevent differential settling under the road or building), or as a low-cost extender that binds with more expensive cement or asphalt to form concrete. Fine and coarse aggregates make up the bulk of a concrete mixture.
3.6 WATERA cement paste is formed by adding water to the cement by the process of hydration. The cement paste combines the aggregate together and fills the voids within it. A lower water-to-cement ratio yields a stronger, more durable concrete, while more water gives a free-flowing concrete with a higher slump. Impure water for making concrete may cause problems in setting or in causing premature failure of the structure. As the reactions proceed, the products of the cement hydration process gradually bond together the individual sand and gravel particles and other components of the concrete to form a solid mass.
Compaction of concrete is the process adopted for expelling the entrapped air from the concrete. In the process of mixing air gets entrapped in the concrete. If the workability is low it indicates that the amount of air entrapped is high. 100 percent compaction is important for strength and durability. Now a day’s durability property has become more important than strength.
3.8 CURINGCuring is the process of controlling the rate of moisture loss from concrete during cement hydration. It can be seen either after placing in the position or during the manufacture of concrete. the hydration of cement takes time of a day, and even weeks. Curing must be undertaken for a reasonable period of time if the concrete is to achieve its potential strength and durability. Curing may also encompass the control of temperature since this affects the rate at which cement hydrates. Curing is designed to keep the concrete in water to prevent the loss of moisture from the concrete during the period in which concrete is gaining strength.
The test specimen are stored in place free from vibration, in moist air of at least 90% relative humidity and at a temperature of 270C + 20C for 24hrs + ½ hrs from the time of addition of water to the dry ingredient. After this period the specimen are marked and removed from the mould and unless required dor test within 24hrs, immediately submerged in clean fresh water or saturated lime solution and kept these until taken out just prior to test. The water or Solution in which the specimen are submerged, are renewed every seven days and are maintained at a temperature of 270C + 20C. The specimen is not to be allowed to become dry at any time until they have been tested.
3.9 MIX DESIGN OF CONCRETEThe method of selecting suitable ingredients of concrete and determining their relative amounts with the objective of producing a concrete of the required, strength, durability, and workability as economically as possible, is termed the concrete mix design. The proportioning of ingredient of concrete is governed by the required performance of concrete in 2 states, namely the plastic and the hardened states. If the plastic concrete is not workable, it cannot be properly placed and compacted. The property of workability, therefore, becomes of vital importance.
3.9.1 REQUIREMENTS OF CONCRETE MIX DESIGN:-The requirements which form the basis of selection and proportioning of mix ingredients are:
a) The minimum compressive strength required for structural construction.
b) The adequate workability necessary for full compaction with the compacting equipment available.
c) Maximum cement content to avoid shrinkage cracking due to temperature cycle in mass concrete.
3.9.2 METHODS OF MIX DESIGN1. INDIAN STANDARD METHOD (IS METHOD)
The I.S. method treats normal mixes (up to M35) and high strength mixes (M40 and above) differently. This is logical because richer mixes need lower sand content when compared with leaner mixes. The method also corrects water cement ratios, workability and for rounded coarse aggregate. In IS method, the quantities of fine and coarse aggregate are calculated with the help of yield equation, which is based on specific gravities of ingredients. Thus plastic density of concrete calculated from yield equation can be close to actual plastic density obtained in laboratory, if specific gravities are calculated accurately. Thus we can find the actual cement consumption closer to the targeted in the first trial mix itself. The water cement ratio is calculated from cement curves graph based on 28 days strength of cement. This can be time consuming and impractical at times. The IS method gives separate graphs using accelerated strength of cement with reference mix method. This greatly reduces the time required for mix design.
2.DEPARTMENT OF ENVIRONMENT METHOD (DOE METHOD)
The DOE method overcomes from some limitations of IS method. In DOE method, the fine aggregate content is a function of 600micron passing fraction of sand and not the zone of sand. The 600-micron passing fraction emerges as the most critical parameter governing the cohesion and workability of concrete mix. Thus sand content in DOE method is more sensitive to changes in fineness of sand when compared to the IS method. The sand content is also adjusted as per workability of mix. It is well accepted that higher the workability greater is the fine aggregate required to maintain cohesion in the mix. The water content per m3 is recommended based on workability requirement given in terms of slump and Vee Bee time. It recommends different water contents for crushed aggregates and for natural aggregates. The quantities of fine and coarse aggregates are calculated based on plastic density. However the DOE method allows simple correction in aggregate quantities for actual plastic density obtained at laboratory.
3. AMERICAN CONCRETE INSTITUTE METHOD (ACI METHOD)
This method is based on determining the coarse aggregate content based on, dry rodded coarse aggregate bulk density and fineness modulus of sand. Thus this method takes into account the actual voids in compacted coarse aggregates that are to be filled by sand cement water. This method also gives separate tables for air-entrained concrete. This method is most suitable for design of air-entrained concrete. This method gives separate values of water and sand content for maximum size of aggregate up to 150mm. Hence this is most suitable method for designing plum concrete. It also gives separate values for 12.5 and 25 mm down coarse aggregate.
4. THE RRL METHOD (ROAD NOTE 4 METHOD)
In this method, the aggregate to cement ratios are worked out on the basis of type of aggregate, max size of aggregate and different levels of workability. The relative proportion of aggregates is worked on basis of combined grading curves. This method facilitates use of different types of fine and coarse aggregates in the same mix. The relative proportion of these can be easily calculated from combined grading curves. The values of aggregate to cement ratio are available for angular rounded or irregular coarse aggregate.
3.9.3 FACTORS AFFECTING THE CHOICE OF MIX PROPORTIONS:-
The various factors affecting the mix design are:
1. Compressive strength
4. Maximum nominal size of aggregate
5. Grading and type of aggregate
6. Quality Control
1. Determine the mean target strength ft from the specified characteristic compressive strength at 28-day fck and the level of quality control.
ft = fck + 1.65 S
where S is the standard deviation obtained from the Table 1of approximate contents given after the design mix.
2. Calculate water cement ratio for the desired mean target strength using the empirical relationship between compressive strength and water cement ratio. The water cement ratio is then chosen and checked against the limiting water cement ratio for the requirements of durability and adopts the lower of the two values.
3. Estimate the amount of entrapped air for maximum nominal size of aggregate.
4. Select the water content, for the required workability and maximum size of aggregates.
5. Determine the percentage of fine aggregate in total aggregate by absolute volume for the concrete using crushed coarse aggregate.
6. Adjust the values of water content and percentage of sand as provided in IS Codes for any difference in workability, water cement ratio, grading of fine aggregate and for rounded aggregate.
7. Calculate the cement content from the water-cement ratio and the final water content as arrived after adjustment. Check the cement against the minimum cement content from the requirements of the durability, and greater of the two values is adopted.
8. From the quantities of water and cement per unit volume of concrete and the percentage of sand already determined in steps 6 and 7 above, calculate the content of coarse and fine aggregates per unit volume of concrete.
9. Determine the concrete mix proportions for the first trial mix.
10. Prepare the concrete using the calculated proportions and cast three cubes of 150 mm size and test them wet after 28-days moist curing and check for the strength.
11. Prepare trial mixes with suitable adjustments till the final mix proportions are arrived at.
3.10 TEST REQUIRED.3.10.1 TEST OF CEMENT:
184.108.40.206 FINENESS TEST AS PER IS: 4031 (Part 3) – 1996: The fineness of cement has an important bearing on the rate of hydration and hence on the rate of gain of strength and also on the rate of evaluation of heat. The fineness of cement is tested by sieving method. Sieve method: weigh correctly 100 gram of cement and take it on a standard IS Sieve No 9 that is 90 microns. Breakdown the lumps in the fine sample with finger. Continuously sieve the sample by giving circular and vertical motion for a period of 15 minutes. Weigh the residue left on the sieve. The weight should not exceed 10% of ordinary cement.
220.127.116.11 SETTING TIME TEST AS PER IS: 4031 (PART 5) – 1988:
The setting time of cement is finding out by following:
Normal Consistency of cement,
Initial setting time,
iii) Final setting time.
Initial setting time is regarded as the time elapsed between the water is added to the cement and the time cement paste starts losing its plasticity. The final setting time is the time elapsed between the water is added to the cement and paste has completely lost its plasticity and has attained sufficient firmness to resist certain definite pressure.
3.10.2 TEST OF AGGREGATE AS PER IS 2386-5 (1963)18.104.22.168 SPECIFIC GRAVITY OF FINE AGGREGATEThe specific gravity of an aggregate is generally required for calculations in connection with cement concrete design work for determination of moisture content and for the calculations of volume yield of concrete. The specific gravity also gives information on the quality and properties of aggregate.
1. Find the weight of the empty container W1.
2. Take coarse aggregate in the container up to approximately half of the container and find out the weight W2.
3. Fill the container with water upto the level of the coarse aggregates so that all void space inside the aggregate is filled with water. Find its weight W3.
4. Fill the container with water after emptying it from mix of coarse aggregate and water.
5. Water should be upto the mark, upto which coarse aggregate is filled. Find its weight W4
6. Repeat the same process for another trail by taking the aggregate upto the full of the container and by filling the water up to same point.
Specific gravity = Weight of solids / Volume of Solids
W2 – W1 / ((W4 – W1) – (W3 – W2)
22.214.171.124 FINENESS MODULUSTESTSieve analysis is used in determining the particle size distribution of the coarse and fine aggregates. This is done by sieving the aggregates as per IS: 2386 (Part I) – 1963. In this we use various sieves as standardized by the IS code and then pass the aggregates through those sieves and collect the different sized particles retained above the sieve and note the sieve size with weight retained .
1. Take 5Kg of coarse aggregate (nominal size 20mm) from the sample by quartering.
2. Carry out sieving by hand, shake each sieve in order 75mm ,40mm, 20mm, 10mm, and
No’s 480, 240, 120, 60, 30, and 15 over a clean dry tray for a period of not less than 2 minutes.
3. The shaking is done with a varied motion backward and forward, left to right, circular, clockwise and anticlockwise and with frequent jarring.
4. So that material is kept moving over the sieve surface in frequently changing directions.
5. Find the weight retained on each sieve taken in order
1. Take 1 Kg of sand from sample by quartering in clean dry plate.
2. Arrange the sieves in order of No. 480, 240, 120, 60, 30 and 15 keeping sieve 480 at top and 15 at bottom.
3. Fix them in the sieve shaking machine with the pan at the bottom and cover at the top.
4. Keep the sand in the top sieve no 480, carry out the sieving in the set of sieves and arranged before for not less than 10 minutes.
5. Find the weight retained in each sieve.
126.96.36.199. AGGREGATEIMPACTVALUEThis test is done to determine the aggregate impact value of coarse aggregates as per IS: 2386 (Part IV) – 1963. The apparatus used for determining aggregate impact value of coarse aggregates is Impact testing machine conforming to IS: 2386 (Part IV)- 1963,IS Sieves of sizes – 12.5mm and 10mm, A cylindrical metal measure of 75mm dia. and 50mm depth, A tamping rod of 10mm circular cross section and 230mm length, rounded at one end and Oven.
– Passing through 12.5mm IS Sieve – 100%
– Retention on 10mm IS Sieve – 100%
Fig 2. Aggregate Impact Value Apparatus
i) The cup of the impact testing machine should be properly placed in the position on the base of the machine and the whole of the test sample placed in it. Then it is compacted with 25 strokes by tamping rod.
ii) The hammer should be raised to the height of 380mm from the surface of the aggregates in the cup and allowed to fall freely onto the aggregates. The test sample should be subjected to a total of 15 such blows, each being delivered at an interval of not less than one second.
Reporting of Results
The sample should be removed and sieved through a 2.36mm IS Sieve. The fraction passing through is weighed (Weight ‘B’). The fraction retained on the sieve is weighed (Weight ‘C’) and if the total weight (B+C) is less than the initial weight (A) by more than one gram, the result should be discarded and a fresh test done.
The ratio of the weight of the fines formed to the total sample weight should be expressed as a percentage.
Aggregate impact value =(B/A)x100%
iii) Two such tests should be carried out and the mean of the results should be reported.
3.11 TESTING OF CONCRETE3.11.1 WORKABILITY TEST:The quality of concrete satisfying the above requirements is termed as workable concrete. The word “workability” signifies much wider and deeper meaning than the other terminology “consistency” often used loosely for workability. Consistency is a general term to indicate the degree of fluidity or the degree of mobility. A concrete which has high consistency and which is more mobile, need not to be right workability.
Factors affecting Workability:
The factor helping concrete to help more lubricating effect to reduce internal fraction for helping easy compaction are given below:
Size of aggregate
Shape of aggregate
Surface structure of aggregate
Grading of aggregate
Use of admixture
188.8.131.52 WORKABILITY TEST:SLUMP CONE METHODWorkability test is done by Slump Cone method as per IS: 1199 – 1959. Slump test is a most commonly used method for measuring consistency of concrete. It is not a suitable method for very wet or very dry concrete
The apparatus for conducting slump test essentially consist of metallic mould in the form of a frustum of cone having the internal dimension as
Bottom Diameter : 20 cm
Top Diameter : 10 cm
Height: 30 cm
Tempering rod : 16mm dia and 0.6 m long
Fig 3. Slump Cone Apparatus
PROCEDURE OF TESTING:
The internal surface of the mould is thoroughly cleaned and freed from supper flowus moisture and adherence of any old set concrete before commencing the test.
The mould is placed on smooth, horizontal, rigid, and non absorbent surface.
The mould is then field in four layers in approximate 1 fourth of height of mould.
Each layer is tamped 25 times by the tamping rod. After the top layer has been roded, the concrete is stuck of level with trowel.
Then the mould is removed from the concrete immediately by raising it slowly and carefully in vertical direction.
This allows the concrete to subside.
The subsidence is referred as slump of concrete. The difference in level between the height of mould and the height of point of subsided concrete is measured.
This difference in height in mm is taken as slump of concrete. The test is repeated for all mixers.
3.11.2 TESTING OF HARDENED CONCRETE:Testing of Hardened concrete plays an important role in conforming the quality of cement concrete works. As the hardening of the concrete takes time, one will not come to know, the actual strength of concrete for some time. This is an inherent disadvantage in conventional test. But, if strength of concrete is to be known at an early period, accelerated strength test can be carried out to predict 28 days strength. But mostly when correct materials are used and careful steps are taken at every stage of the work, concretes normally give the required strength.
Curing of specimen in the field:-
Fig 4. Curing of concrete sample
The test specimen are stored on the site at a place free from vibration, under damp mating, sacks or other similar material for 24 hour + 30 minute from the time addition of water to the other ingredients. The temperature of the place of storage should be within the range of 220 to 320 C. After the period of 24 hour, they should be marked for later identification removed from the moulds and unless required for testing within 24 hour, stored in clean water at a temp of 240 to 300 C until they are transported to the testing laboratory. They should be sent to the testing laboratory will packed in damp sand, damp sacks or other suitable material so as to arrive there in the damp condition not less than 24 hours before the time of test. On arrival the testing laboratory the specimen are stored in water at a temp 270 + 20 C until the time of test. Record of the daily maximum and minimum temp should be kept both during the period of the specimen remain on the site and in the laboratory particularly in cold weather region.
184.108.40.206. COMPRESSION TEST AS PER IS: 516 – 1959
Compression test is the most common test conducted on hardened concrete, partly because it is an easy test to perform and because most of desirable characteristic properties of concrete of qualitatively related to its compression test.
The compression test is carried out on specimens cubically in shape. The cube specimen is of size 15 X 15 X 15 cm.
Mould: Metal mould preferable steel, or cast iron, thick enough to prevent distortion is required. The mould size 15 X 15 X 15 cm is made in such a manner as to facilitate the removal of moulded specimen without damage.
Compaction: the test cube specimen is made as soon as after mixing and in such a way as to produce full compaction of the concrete without segregation. Hand compaction is done by standard tamping bar used and stroke of the bar are distribution in the uniform manner over the cross section of mould. In this cubical specimen 25 strokes per layer of 10cm height is done.
Next step is to remove the cube from mould.
Curing: the test specimens are stored in place free from vibration, in moist air of at least 90% relative humidity and at a temperature of 27 ? ± 7C for @4 hours from the time of addition of water to the dry ingredients. The water in which the specimens are submerged, is renewed every seventh day.
Then the concrete will be placed on the compressing testing machine and load is applied.
220.127.116.11 TENSILE STRENGTH TEST AS PER IS: 5816 – 1999Concrete is relatively strong in compression and weak in tension in reinforced concrete member, little dependence is placed on the tensile strength of concrete since steel reinforcing bars are provided to resist all tensile force. Tensile stresses are likely to develop in concrete due to drying shrinkage, rusting of steel reinforcement, temperature gradients and many other reasons.
The standard size of specimen is 150mm dia and 300mm height of metal preferable steel or cast iron and the metal should be of sufficient thickness to prevent spreading and warping. The mould should be constructed with the longer dimension horizontal and in such a manner as to facilitate the removal of the moulded specimen without damage.
The prepared mixture should be poured into the mould and tampered 25 times by tampering rod of size 40cm long and 2kg weight.
Then the specimen is removed from mould and stored in water at a temperature 24° c to 30° c.
They are tested immediately on removal from the water.
The dimension of each specimen is noted before testing and no preparation of surface is done.
The bearing surface of the specimen is wiped clean.
The specimen is then placed in the machine in such a manner that the load is applied to the upper most surface as cast in the mould.
The axis of the specimen is carefully aligned with the axis of the loading device.
No packing is used between the bearing surface of the specimen and the roller..
The load is applied without shock and increasing continuously at a rate such that the extreme fiber stress increases.
CHAPTER 4RESULTS AND ANALYSIS4.1 GENERAL
The properties of lathe scrape material were studied properly. It has good reinforcement property when added to concrete. Lathe Scrap material are measured by volume of cement. The cement, aggregate and concrete tests are performed as per Indian Standard Testing procedure. The lathe scrap is added in concrete in various proportion as 0%, 0.5%, 1%,1.5%,2%,2.5% and 3% in size of 20mm . The concrete mixed with lathe scrape were casted and analysed. The different proportions were named for scrape length 20mm as N1, S1, S2, S3, S4, S5 and S6 respectively.
4.2 CONCRETE MIX DESIGN AS PER IS METHOD for M20 Grade :Characteristic of compressive strength required for duration of 28 days as per IS Code
Max size of aggregate 20mm
Degree of quality controlGood
Type of exposureMild
Compressive strength of cement at 7day as per IS: 516 – 1959
Specific gravity of Cement3.15
Specific gravity of Coarse Aggregate2.6
Specific gravity of Fine Aggregate.2.6
Sieve Analysis Test :
Target mean strength of concrete at 28 days
Ft= Fck+ K.SFt= Target Mean Strength of Concrete at 28 days
Fck= Characteristics of Compressive Strength of concrete at 28 days
K Usually 1.65 as per IS 456 : 2000
S Standard deviation as per table no 10 of code IS 456 : 2000
Table2 .Assumed standard deviation:
Grade Of Concrete Assumed Standard deviation
M 15 3.50 N/mm2
M 25 4.00 N/mm2
M50 5.00 N/mm2
Ft= 20 + 1.65 x 4
Selection of Water Cement Ratio: As per Table.5 of IS 456: 2000
Max Water Cement ratio for 20mm sized aggregate in Mild exposure is = 0.6
Thus, for M20 concrete by interpolation, we get W/C Ratio = 0.5
Table 3.Selection of water and sand content per cubic meter of concrete:
Max. Size of Aggregate (mm) Water content per cubic meter of concrete Sand as % of Total aggregate by absolute volume
10 203 40
20 186 35
40 165 30
As per table Water content corresponding to saturated surface dry (S.S.D.) aggregate :
For M 20 Grade of concrete : 186
Sand as % of total aggregate by absolute volume : 35%
According to table no 4 of code IS 383 : 1970 following adjustment is required for Sand:
Change in condition Adjustments Required in
Water content % sand in total Aggregate
For decrease w/c by (0.60 – 0.50 )= 0.10 -3 -2.0
For sand conforming to zone II of table 4 of code IS : 383 – 1970 0 0
Hence from the table, sand content required as % of total aggregate by absolute volume
= 35 – 2.0 = 33 %
Required Water = 186 + 186 X 3.3/ 100
= 186 + 6.138
= 192.14 L/m3
Determination of Cement Content :
Water CementRatio = 0.50
Water = 192.14 L
Cement = (192.14/0.5) = 384.35 kg/m3
This cement content is adequate for Mild exposure condition according IS 456: 2000
Determination of CA and FA Content:
The Max size of aggregate is 20mm. The amount of entrapped air in the wet concrete is 02% taking this into account and applying in equation:
For 1 m3 of wet concrete total volume is taken as
v=1-0.02=0.98v=w+cSc+ 1PfaSfa11000Ca= 1-PPfax SCaSfa0.98=192.14+3.843.15+ 10.33fa2.611000fa = 580.36 kg/m3
Ca= 1-0.330.33fax 2.62.6Ca = 1178.11 kg/m3
MIX PROPORTION BECOMES:
Table 4.Target ratio of M20 concrete
Water (L) Cement (Kg/m3) Fine Aggregate (Kg/m3) Coarse Aggregate (Kg/m3)
192.14 384.35 587.36 1188.11
0.50 1 1.55 3.16
4.3 RESULT OF CEMENT TEST:TEST RESULTS OF CEMENT
Table 5. Cement Test
CEMENT TEST RESULT
Initial Setting Time 30min 35 Sec
Final Setting Time 10 Hours
Specific gravity of Cement 3.15
Weight of cement (W1)=200g
Weight of cement retain on IS Sieve (90 micron) (W2)= 4.9g
Percentage of cement retained= N200X 100=4.9200X100Fineness of cement= 2.45%
4.4 RESULT OF AGGREGATE TEST:Table 6. TEST RESULTS OF AGGREGATE
AGGREGATE TEST RESULT
Bulk Density 1490 Kg/m3
Specific Gravity: Fine aggregate
Course aggregate 2.6
Fineness Modulus 6.66
Abrasion Test 26.3
Impact Value 13.95
Crushing Value 19.11
4.4.1. BULK DENSITY TESTWeight of compacted aggregate = 4470Kg
Volume of container= 3 X 10-3 m3
Bulk density of aggregate= weight of compacted aggregatevolume of container= 44703X 10-3Bulk density of aggregate = 1490Kg/m3
4.4.2 SPECIFIC GRAVITY OF COURSE AGGREGATEWeight of basket (W1)= 2.522Kg
Weight of basket with course aggregate (W2)= 4.470 Kg
Weight of basket with course aggregate in water (W3) = 6.23Kg
Weight of basket in water (W4) = 5.03Kg
Specific Gravity= W2-W1W2-W1-(W3-W4) =4.470-2.5224.470-2.522-(6.23-5.03)Specific Gravity=2.604
4.4.3 IMPACT VALUE TESTWeight of empty pan (W1) = 1.680 Kg
Weight of aggregate with pan (w2)= 2.18Kg
Thus, aggregate (A)= 2.180- 1.680=0.5.Kg
Fraction passing through 2.36mm sieve(B)=0.07Kg
Percentage of loss =BAX 100= 0.0700.501X100
Aggregate impact value = 13.95
4.6.4 ABRASION VALUE
Original weight of course aggregate (W1) = 5Kg
Weight of retained course aggregate on 1.7mm sieve (W2) = 3.685Kg
Abrasion value = W1-W2W1= 5-3.6855Abrasion value = 26.30
4.5 TEST RESULTS OF LATHE SCRAPE CONCRETE4.5.1 SLUMP VALUE (WORKABILITY TEST):
Table 7.Slump value of lathe scrap of 20mm size
Nature Of Concrete N1 S1 S2 S3 S4 S5 S6
Slump Value (cm) 28.6 28.1 27.8 27.4 27.1 26.8 26.3
As shown in Graph1, the Slump Value of lathe scrap steel fiber reinforced concrete for 20mm is 28.6cm, 28.1cm, 27.8cm, 27.4cm, 27.1cm, 26.8cm and 26.3cm for ratio 0%, 0.5%, 1%, 1.5%, 2%, 2.5% and 3% respectively. The slump value is decreasing as the percentage of concrete increases, thus it indicates that as amount of steel scrap fiber increase the workability decreases.
Graph 1. Slump Value of Concrete with steel scrap fiber
4.5.2 COMPRESSIVE STRENGTH TEST:
As it is evident from Table 8, an enhancement in 28 days compressive strength compared to control sample and steel scrap fiber concrete for all size of 20 mm fiber lengths. Also an increase in the fiber content has direct effect on compressive strength. Higher compressive strength of LWC specimens as 32.40 KN/mm2 at 28th day of curing with 3% of steel scrap fiber. The result of the compressive strength of concrete cubes show that the compressive strength increases as percentages of fiber increased.
Table 8. Compressive Strength Test of Concrete with steel scrap Fiber
Name Quantity Of steel Fiber w.r.t cement Quantity of ingredients (Kg/m3) Compressive Strength Of Concrete
Size (mm) Cement Sand Aggregate Steel scrap fiber 7Day 14Day 28Day
N1 – – 384.35 580.4 1176.1 0 18.62 18.56 20.53 20.35 26.20 26.31
18.13 20.29 26.32 18.94 20.26 26.35 S1 0.50% 20 384.35 580.4 1176.1 1.92 18.60 18.67 20.30 20.50 26.23 26.43
18.50 20.20 26.54 18.90 20.40 26.40 S2 1% 20 384.35 580.4 1176.1 3.84 18.90 18.89 20.70 20.75 27.17 27.17
18.84 21.60 27.16 18.94 20.80 27.22 S3 1.50% 20 384.35 580.4 1176.1 5.77 19.40 19.20 21.00 21.15 27.43 27.36
19.00 21.10 27.34 19.20 21.20 27.31 S4 2% 20 384.35 580.4 1176.1 7.68 19.50 19.37 21.50 21.32 27.57 27.56
19.10 21.00 27.55 19.70 21.90 27.67 S5 2.50% 20 384.35 580.4 1176.1 9.61 19.60 19.50 21.60 21.70 27.86 27.83
19.90 21.70 27.80 19.20 21.80 27.78 S6 3% 20 384.35 580.4 1176.1 11.52 19.80 19.80 22.20 22.10 28.40 28.40
19.80 22.00 28.20 19.60 22.40 28.20 COMPRESSIVE STRENGTH OF CONCRETE ON 7th DAY OF CURING
From the Graph 2, it is noted that the 20mm length fiber in concrete as the reinforcement increases the strength of concrete. The combined Graph of compressive strength of concrete with steel fiber reinforced shows that addition of 3% fiber by weight of cement of 20mm size giver better result out of all other options. The strength of concrete of 20mm size fiber is 18.56 N/mm2, 18.67 N/mm2, 18.89 N/mm2 , 19.2 N/mm2, 19.37 N/mm2, 19.5N/mm2 and 19.8N/mm2 for N1, S1, S2, S3, S4, S5 and S6 respectively at 7th day of curing. The concrete gives higher strength when 3% steel fiber is added. It shows that, higher the percentage of fiber higher the compressive strength of concrete.
Graph 2: Compressive Strength on 7th day of curing
COMPRESSIVE STRENGTH OF CONCRETE ON 14th DAY OF CURING
From the Graph 3, it is noted that the 20mm length fiber in concrete as the reinforcement increases the strength of concrete. The combined Graph of compressive strength of concrete with steel fiber reinforced shows that addition of 3% fiber by weight of cement of 20mm size giver better result out of all other options. The strength of concrete of 20mm size fiber is 20.35N/mm2, 20.5 N/mm2, 20.75 N/mm2 , 21.15 N/mm2, 21.32 N/mm2, 21.7N/mm2 and 22.1 N/mm2 for N1, S1, S2, S3, S4, S5 and S6 respectively at 14th day of curing. The concrete gives higher strength when 3% steel fiber is added. It shows that, higher the percentage of fiber higher the compressive strength of concrete.
Graph 3: Compressive Strength on 14th day of curing
COMPRESSIVE STRENGTH OF CONCRETE ON 28th DAY OF CURING
From the Graph 4, it is noted that the 20mm length fiber in concrete as the reinforcement increases the strength of concrete. The combined Graph of compressive strength of concrete with steel fiber reinforced shows that addition of 3% fiber by weight of cement of 20mm size giver better result out of all other options. The strength of concrete of 20mm size fiber is 26.31N/mm2, 26.43 N/mm2, 27.17 N/mm2 , 27.36 N/mm2, 27.56 N/mm2, 27.83N/mm2 and 28.4 N/mm2 for N1, S1, S2, S3, S4, S5 and S6 respectively at 28th day of curing. The concrete gives higher strength when 3% steel fiber is added. It shows that, higher the percentage of fiber higher the compressive strength of concrete.
Graph 4: Compressive Strength on 14th day of curing
COMBINED COMPRESSIVE STRENGTH OF CONCRETE
Graph 5: Combined Graph Of Compressive Strength Of Concrete
The reinforcement provided by fibres can work at both a micro and macro level. At a micro level fibres arrest the development of micro-cracks, leading to higher compressive strengths, whereas at a macro level fibres control crack opening, increasing the energy absorption capacity of the composite. Although the primary purpose of fibre reinforcement is to improve energy absorption capacity after macro-cracking of the matrix has occurred, this reinforcement often works also at a micro level. The ability of the fibre to control micro cracking growth depends mainly on the number of fibres, deformability and bond to the matrix. A higher number of fibres in the matrix leads to a higher probability of a micro-crack being intercepted by a fibre.
From Graph 5, it is observed that Compressive Strength increases as volume of Steel fiber increases. As per the previous research it is observed that the using Steel fiber upto 3% in concrete is good. The Compressive Strength of concrete with steel Fiber reinforced in proportions of 0%, 0.5%, 1.0%, 1.5%, 2.0%, 2.5% and 3.0% is 26.31MPa, 26.43MPa, 27.17MPa, 27.36MPa, 27.56MPa, 27.83MPa and 28.4MPa at 28th day of curing respectively. The Compressive strength is in increasing order and the maximum strength is gained at 3.0% of steel fiber use concrete that is 28.4 MPa.
4.5.3 SPLIT TENSILE STRENGTH TEST:
Split tensile strengths of steel scrap fiber concretes were found to be higher compared to reference concrete. It can be observed that the fiber concrete specimens containing longer fiber show the best split tensile strength among all concretes.
Table 9. Split Tensile strength of concrete with steel scrap fiber
Name Quantity Of steel scrap Fiber w.r.t cement Quantity of ingredients (Kg/m3) Split Tensile Strength Of Concrete (N/mm2)
Size Cement Sand Aggregate steel fiber 7Day 14Day 28Day
N1 – – 384.35 580.4 1176.1 0 0.98 0.91 1.14 1.17 2.96 2.96
0.89 1.15 2.97 0.86 1.23 2.95 S1 0.5% 20 mm 384.35 580.4 1176.1 1.92 0.95 1.03 1.29 1.31 3.10 3.10
1.1 1.28 3.08 1.03 1.37 3.12 S2 1% 20 mm 384.35 580.4 1176.1 3.84 1.15 1.17 1.51 1.54 3.90 3.90
1.14 1.50 3.99 1.06 1.62 3.81 S3 1.5% 20 mm 384.35 580.4 1176.1 5.77 1.32 1.29 1.98 1.87 4.20 4.3
1.22 1.86 4.35 1.32 1.77 4.36 S4 2% 20 mm 384.35 580.4 1176.1 7.68 1.53 1.5 2.08 2.08 4.60 4.65
1.41 2.10 4.64 1.55 2.06 4.76 S5 2.5% 20 mm 384.35 580.4 1176.1 9.61 1.80 1.78 2.22 2.25 4.80 4.8
1.67 2.30 4.90 1.86 2.24 4.70 S6 3% 20 mm 384.35 580.4 1176.1 11.52 1.90 1.97 2.40 2.4 4.99 4.98
2.07 2.49 5.03 1.93 2.30 4.92 SPLIT TENSILE STRENGTH OF CONCRETE ON 7th DAY OF CURING
From the Graph 6, it is noted that the 20mm length fiber in concrete as the reinforcement increases the strength of concrete. The combined Graph of Split Tensile strength of concrete with steel fiber reinforced shows that addition of 3% fiber by weight of cement of 20mm size giver better result out of all other options. The strength of concrete of 20mm size fiber is 0.91N/mm2, 1.03 N/mm2, 1.17 N/mm2 , 1.29 N/mm2, 1.5N/mm2, 1.78N/mm2 and 1.97 N/mm2 for N1, S1, S2, S3, S4, S5 and S6 respectively at 7th day of curing. The concrete gives higher strength when 3% steel fiber is added. It shows that, higher the percentage of fiber higher the compressive strength of concrete.
Graph 6: Split Tensile Strength on 7th day of curing
SPLIT TENSILE STRENGTH OF CONCRETE ON 14th DAY OF CURING
From the Graph 7, it is noted that the 20mm length fiber in concrete as the reinforcement increases the strength of concrete. The combined Graph of Split Tensile strength of concrete with steel fiber reinforced shows that addition of 3% fiber by weight of cement of 20mm size giver better result out of all other options. The strength of concrete of 20mm size fiber is 1.17N/mm2, 1.31 N/mm2, 1.54N/mm2 , 1.87N/mm2, 2.08N/mm2, 2.25N/mm2 and 2.4N/mm2 for N1, S1, S2, S3, S4, S5 and S6 respectively at 14th day of curing. The concrete gives higher strength when 3% steel fiber is added. It shows that, higher the percentage of fiber higher the compressive strength of concrete.
Graph 7: Split Tensile Strength on 14th day of curing
SPLIT TENSILE STRENGTH OF CONCRETE ON 28th DAY OF CURING
From the Graph 8, it is noted that the 20mm length fiber in concrete as the reinforcement increases the strength of concrete. The combined Graph of Split Tensile strength of concrete with steel fiber reinforced shows that addition of 3% fiber by weight of cement of 20mm size giver better result out of all other options. The strength of concrete of 20mm size fiber is 2.96N/mm2, 3.1 N/mm2, 3.9N/mm2 , 4.3N/mm2, 4.65N/mm2, 4.8N/mm2 and 4.98 N/mm2 for N1, S1, S2, S3, S4, S5 and S6 respectively at 28th day of curing. The concrete gives higher strength when 3% steel fiber is added. It shows that, higher the percentage of fiber higher the compressive strength of concrete.
Graph 8: Split Tensile Strength on 28th day of curing
COMBINED SPLIT TENSILE STRENGTH OF CONCRETE
From Graph 9, it is observed that Split Tensile Strength increases as volume of Steel fiber increases. As per the previous research it is observed that the using Steel fiber upto 3% in concrete is good. The Split Tensile Strength of concrete with steel Fiber reinforced in proportions of 0%, 0.5%, 1.0%, 1.5%, 2.0%, 2.5% and 3.0% is 2.96MPa, 3.1MPa, 3.9MPa, 4.3MPa, 4.65MPa, 4.8MPa and 4.98MPa at 28th day of curing respectively. The Split Tensile strength is in increasing order and the maximum strength is gained at 3.0% of steel fiber use concrete that is 4.98MPa.
Graph 9: Combined Split Tensile Strength of Concrete
CHAPTER 5CONCLUSIONInnovations in engineering design and construction, which is need for economy and high strength with light weight building materials. Fiber-reinforced concrete is very close to fulfil their expectations of researchers. In the past several years, countries are focusing on development of infrastructure, thus there is a sudden boom in construction activities. Increase in number of constructions have taken place, with fiber reinforced concrete in foundation piles, prestressed piles, piers, highways, industrial floors, bridge decks, facing panels, floatation units for walkways etc, because of its high strength and light weight. This has also been used for controlling shrinkage and temperature cracking.
Based on the test specimens made with the available local materials, the following conclusions can be derived:
Compressive and tensile strength of Concrete increases with increase in fiber content.
It is observed that compressive and split tensile strength of concrete reinforced with Aspect ratio 66 (20 mm long) Steel Scrap fiber is higher than the normal reinforced concrete.
The Compressive Strength of SFRC (Aspect ratio 66(20mm long and 0.3mm diameter) for proportions of 0%, 0.5%, 0.10%, 1.5%, 2%, 2.5% and 3% are 22.31MPa, 22.43 MPa, 23.17 MPa, 23.36MPa, 23.56MPa, 23.83MPa and 24.4MPa respectively at 28th day of curing.
The Split Tensile strength of SFRC for proportions of 0%, 0.5%, 0.10%, 1.5%, 2%, 2.5% and 3% are 2.96MPa, 3.1 MPa, 3.9MPa, 4.3MPa, 4.65MPa, 4.8MPa and 4.98MPa respectively at 28th day of curing.
With the use of 3% of steel fibre gives the maximum result in compression as 15.8MPa, 20.10MPa and 24.4MPa at 7th day, 14th day and 28th day of curing respectively.
With the use of 3% of steel fibre gives the maximum result in Split Tensile Strength as 1.97MPa, 2.4MPa and 4.98MPa at 7th day, 14th day and 28th day of curing respectively.
From the result it is observed that the workability of Steel Fibre reinforced concrete decreases as the percentage of steel fibres increases.
The addition of Steel Fibre in concrete increases the Tensile properties of concrete and also improves resistance to cracking.
1. Further investigations can be done to explore compressive ; tensile strength of concrete reinforced with 25% to 45% fibers, with an increment of 5%.
2. Fiber with 12 mm to 25 mm length may also be explored for reinforcement, in concrete.
3. Fibers may also be explored to improve soil properties.
Chapter 6REFERENCESAbdul Rahman et.al. Performance Analysis of Steel Scrap in Structural Concrete: Journal of Mechanical and Civil Engineering (IOSR-JMCE)e-ISSN: 2278-1684,p-ISSN: 2320-334X, Volume 14, Issue 2 Ver. VII (Mar. – Apr. 2017).
Ashok, S. P.; Suman, S.; Chincholkar, N. (2012). Reuse of steel scrap from lathe machine as reinforcing material to enhance properties of concrete.Global J. of Engg.; Appl. Sciences, ISSN, 2(2), 164-167. (2011). Shear strength model for steel fiber reinforced concrete beams without stirrup reinforcement. Journal of Structural Engineering, ASCE, 137(10), 1039-1051.
Awanish Kumar Shukla investigated on “Application of CNC waste with recycled Aggregate in Concrete mix” – 2013.
Awanish Kumar Shukla investigated on “Application of CNC waste with recycled Aggregate in Concrete mix” – 2013.
Dhilip kumar and Shankar : An Experimental Study On Mechanical Properties Of Scrap Reinforced Concrete Using Waste Metal, International Journal Of Intelligence Research (IJOIR) Volume 8, July – December 2016.
E. Mello et al, have studied on “Improving concrete properties with fiber addition”.
G Vijayakumar et.al.: Impact And Energy Absorption Characteristics Of Lathe Scrap Reinforced Concrete, international journal of structural and civil engineering research, vol 1 no1 November 2012.
Haldkar and Ashwini Salunke: Analysis of Effect of Addition of Lathe Scrap on the Mechanical Properties of Concrete, International Journal of Science and Research (IJSR) ISSN (Online): 2319-7064.
Irwan lie Keng Wong had research on “Study of Utilization of waste lathe scrap on increasing compressive strength and Tensile strength”.
IS: 10262-2009, Guidelines for concrete mix design proportioning, Bureau of Indian Standard, New Delhi.
IS: 10262-2009, Guidelines for concrete mix design proportioning, Bureau of Indian Standard, New Delhi.
IS: 383-1970, Specification for coarse and fine aggregate from natural source of concrete, Bureau of Indian Standard, New Delhi.
IS: 383-1970, Specification for coarse and fine aggregate from natural source of concrete, Bureau of Indian Standard, New Delhi.
IS: 516-1959, Method of Testing Strength of Concrete, Bureau of Indian Standard, New Delhi.
IS: 9103-1999, concrete admixture – specification, Bureau of Indian Standard, New Delhi.
IS: 9103-1999, concrete admixture – specification, Bureau of Indian Standard, New Delhi.
Pooja Shrivastava and Dr.Y.p. Joshi: Reuse of Lathe Waste Steel Scrap in Concrete Pavements, International. Journal of Engineering Research and Applications www.ijera.com ISSN : 2248-9622, Vol. 4, Issue 12( Part 4), December 2014.
Prof. Kumaran M et.al. : Effect of Lathe Waste in Concrete as Reinforcement, International Journal of Research in Advent Technology (E-ISSN: 2321-9637) Special Issue International Conference on Technological Advancements in Structures and Construction “TASC- 15”, 10-11 June 2015.
R. Rajkumar et al, “Study on the properties of High Strength concrete using Glass powder and Lathe scrap”- March 2014.
R. Rajkumar et al, “Study on the properties of High Strength concrete using Glass powder and Lathe scrap”- March 2014.
Seetharam. P. G et.al: Studies on Properties of Concrete Replacing Lathe Scrap, International Journal of Engineering Research ; Technology (IJERT) Vol. 6 Issue 03, March-2017.
Sheetal Chinnu James: EXPERIMENTAL STUDY ON FIBER REINFORCED CONCRETE USING LATHE SCRAP FIBER, international journal of advanced technology in engineering and science Vol. No.3, special issue No. 01 September 2015.
Vijayakumar, G.;Senthilnathan, P.; Pandurangan, K.; Ramakrishna, G.(2012). Impact and energy absorption characteristics of lathe scrap reinforced concrete. International Journal of Structural and Civil Engineering Research, IJSCER, 1(1), 60-66.
Zeeshan Nissar Qureshi1, Yawar Mushtaq Raina: Strength Characteristics Analysis of Concrete Reinforced With Lathe Machine Scrap” International Journal of Engineering Research and General Science Volume 4, Issue 4, July-August, 2016″.
MS. Shetty – “Concrete technology – Theory and practice” S. Chand and company, 2008.
TOC o “1-3” h z u Chapter-1: Introduction………………………………………………………………………………… PAGEREF _Toc508287410 h 11.1 General PAGEREF _Toc508287411 h 11.2 Concrete PAGEREF _Toc508287412 h 11.3 Motivation PAGEREF _Toc508287413 h 21.4 Objective PAGEREF _Toc508287414 h 21. 5 Scope PAGEREF _Toc508287415 h 31.6 Methodology PAGEREF _Toc508287416 h 41.7 Organization Of Thesis PAGEREF _Toc508287417 h 4Chapter 2 PAGEREF _Toc508287418 h 7Literature Review PAGEREF _Toc508287419 h 72.1 General PAGEREF _Toc508287420 h 72.2 Fibre Reinforced Concrete PAGEREF _Toc508287422 h 72.3 Literature Review PAGEREF _Toc508287426 h 8Chapter 3 PAGEREF _Toc508287427 h 13Materials And Methodology PAGEREF _Toc508287428 h 133.1 General PAGEREF _Toc508287429 h 133.2 Lathe Scrape PAGEREF _Toc508287430 h 133.3 Cement PAGEREF _Toc508287432 h 133.3.1 Portland Cement PAGEREF _Toc508287433 h 143.4 Sand PAGEREF _Toc508287434 h 153.5 Aggregate PAGEREF _Toc508287435 h 153.6 Water PAGEREF _Toc508287436 h 163.7 Compaction PAGEREF _Toc508287437 h 163.8 Curing PAGEREF _Toc508287438 h 163.9 Mix Design Of Concrete PAGEREF _Toc508287439 h 173.9.1 Requirements Of Concrete Mix Design:- PAGEREF _Toc508287440 h 173.9.2 Methods Of Mix Design PAGEREF _Toc508287441 h 173.9.3 Factors Affecting The Choice Of Mix Proportions PAGEREF _Toc508287442 h 193.9.4 Procedure PAGEREF _Toc508287443 h 193.10 Test Required. PAGEREF _Toc508287444 h 203.10.1 Test Of Cement: PAGEREF _Toc508287445 h 18.104.22.168 Fineness Test As Per Is: 4031 (Part 3) – 1996 PAGEREF _Toc508287446 h 22.214.171.124 Setting Time Test As Per Is: 4031 (Part 5) – 1988: PAGEREF _Toc508287447 h 213.11.2 Test Of Aggregate As Per Is 2386-5 (1963) PAGEREF _Toc508287448 h 126.96.36.199 Specific Gravity Of Fine Aggregate PAGEREF _Toc508287449 h 188.8.131.52 Fineness Modulus Test PAGEREF _Toc508287450 h 184.108.40.206. Aggregate Impact Value PAGEREF _Toc508287451 h 233.12 Testing Of Concrete PAGEREF _Toc508287452 h 243.12.1 Workability Test: PAGEREF _Toc508287453 h 243.12.1.1 Workability Test:Slump Cone Method PAGEREF _Toc508287454 h 243.12.2 Testing Of Hardened Concrete: PAGEREF _Toc508287455 h 2220.127.116.11. Compression Test As Per Is: 516 – 1959 PAGEREF _Toc508287456 h 218.104.22.168 Tensile Strength Test As Per Is: 5816 – 1999 PAGEREF _Toc508287457 h 28Chapter 4 PAGEREF _Toc508287458 h 29Results And Analysis PAGEREF _Toc508287459 h 294.1 General PAGEREF _Toc508287460 h 294.2 Concrete Mix Design As Per Is Method For M20 Grade : PAGEREF _Toc508287461 h 294.3 Result Of Cement Test: PAGEREF _Toc508287462 h 334.4 Result Of Aggregate Test: PAGEREF _Toc508287463 h 344.4.1. Bulk Density Test PAGEREF _Toc508287464 h 344.4.2 Specific Gravity Of Course Aggregate PAGEREF _Toc508287465 h 354.4.3 Impact Value Test PAGEREF _Toc508287466 h 354.5 Test Results Of Lathe Scrape Concrete PAGEREF _Toc508287467 h 364.5.1 Slump Value (Workability Test): PAGEREF _Toc508287468 h 364.5.2 Compressive Strength Test PAGEREF _Toc508287469 h 374.5.3 Split Tensile Strength Test: PAGEREF _Toc508287470 h 40Chapter 5 PAGEREF _Toc508287471 h 45Conclusion PAGEREF _Toc508287472 h 47Chapter 6 PAGEREF _Toc508287473 h 49References PAGEREF _Toc508287474 h 49