International Journal of Research and Innovation (IJRI)
International Journal of Research and Innovation (IJRI) EXPERIMENTAL INVESTIGATION OF SELF COMPACTING CONCRETE BY VARY1401-1402 ING PERCENTAGE OF FINE AGGREGATE TO TOTAL AGGREGATE RATIO FOR DIFFERENT GRADES OF CONCRETE J.P.Alankruta1, S.Uttamraj2, 1 Research Scholar, Department of Civil Engineering, Aurora's Scientific Technological and Research Academy, Hyderabad, India. 2 Assistant professor , Department of Civil Engineering, Aurora's Scientific Technological and Research Academy, Hyderabad, India.
Abstract Self-compacting concrete was first developed 1988 in order to achieve durable concrete structures. Since then, various investigations have been carried out and the concrete has been used in practical structures in Japan, mainly by large construction companies. Investigations for establishing a rational mix-design method and self-compactability testing methods have been carried out to make the concrete the standard one. The Self compaction concrete developed by Prof. Hajime Okamura of Japan in 1986, but the prototype was first developed in 1988 in Japan by Professor Ozawa at the University of Tokyo. Now spread across all countries in the world. Self – compacting concrete (SCC) is a high – performance concrete that can flow under its own weight to completely fill the form work and self consolidates without any mechanical vibration. Such concrete an accelerate the placement, reduce the labor requirements needed for consolidation, finishing and eliminate environmental pollution. The so called first generation SCC is used mainly for repair application and for casting concrete in restricted areas, including sections that present limited access to vibrate. Such value added construction material has been used in applications justifying the higher material and quality control cost when considering the simplified placement and handling requirements of the concrete.
*Corresponding Author: J.P.Alankruta, Research Scholar, Department of Civil Engineering, Aurora's Scientific Technological and Research Academy, Hyderabad, India. Published: August 03, 2015 Review Type: peer reviewed Volume: II, Issue : III
Citation:J.P.Alankruta ,Research Scholar (2015) "EXPERIMENTAL INVESTIGATION OF SELF COMPACTING CONCRETE BY VARYING PERCENTAGE OF FINE AGGREGATE TO TOTAL AGGREGATE RATIO FOR DIFFERENT GRADES OF CONCRETE"
INTRODUCTION GENERAL Self compacting concrete (SCC) has been described as "the most revolutionary development in concrete construction for several decades". Originally developed to offset a growing shortage of skilled labour, it has proved beneficial economically because of a number of factors, including: • Faster construction • Reduction in site manpower • Better surface finish • Easier placing • Improved durability • Greater freedom in design • Thinner concrete sections • Reduced noise levels, absence of vibration • Safe working environment For several year beginning in 1983, the problem of the durability of concrete structures was a major topic of interest in Japan. To make the durable structures, sufficient
compaction by skilled workers was required. However gradual reduction in the number of skilled workers led to a similar reduction in the quality of construction work. At this time Prof. Hajime Okamura at the University of Tokyo in Japan wanted to solve the problem of degrading quality of construction and he had come out with a new concrete called Self Compacting Concrete that would consolidate under its own weight. This type of concrete would directly bypass the need for external vibration, eliminating the problem of unskilled labor. So, Self Compacting Concrete is defined as highly workable concrete that can flow through densely reinforced or geometrically complex structural elements under its own weight to adequately fill the voids without segregation or excessive bleeding and without vibration. The main advantage of the Self compacting concrete is to shorten construction period and to assure compacting in the structures especially in the confined zones where vibration and compaction is difficult. DEVELOPMENT OF SCC The Self compaction concrete developed by Prof. Hajime Okamura of Japan in 1986, but the prototype was first developed in 1988 in Japan by Professor Ozawa at the University of Tokyo. Now spread across all countries in the world. Some notable structures that have utilized Self compacting concrete are as given below. • Honshu-Shikoku Bridge: The largest suspension bridge in the world linking two of the four main islands in Japan. SCC was used in the anchorages of this bridge. • Oresund Project in Scandinavia: SCC was used in the motorway and railway that link Denmark and Sweden. • World largest liquid natural gas (LNG) storage tank: 180 million liters of LNG contained in a tank created using 12000 cubic meters of SCC
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• In India , most of the municipal roads in Chennai doing with SCC • In Andhra Pradesh Lanco hills completing by SCC
erties. Before it satisfies the hardened properties it should also satisfy the fresh properties in terms of filling ability, passing ability and segregation resistance. The self compatibility is largely affected by the characteristics of the materials and mix proportions. As on today there is no established methodology to arrive at the mix proportions. •The strength of SCC is provided by the aggregate binding by the paste at hardened state, while the workability of SCC is provided by the binding paste at fresh state. Therefore, the contents of coarse and fine aggregates, binders, mixing water and SP will be the main factors influencing the properties of SCC. EXPERIMENTAL PROGRAMME
Necessity of Self-Compacting concrete
Research as well as construction applications have been ongoing with SCC since its development. The goal of Self Compaction Concrete shall be to make it a common construction material used internationally to create durable and reliable structures. ADVANTAGES • It increases the hydration products and reduces the porosity of the concrete. • It fills and closes the pores or adjusts the type of pore structure. • It increases hydration products in addition to the filling effect of micro aggregate. • It adjusts the grading of the components to achieve an optimum compact. • It can adjusts the cohesiveness and reduce the heat of hydration and reaction rate • It can improve the workability. • It can improve the durability and resistance to chemical attack and reduces micro cracks and transition zones. • It will offer the concrete high strength and high performance. Fly ash, sometimes called as pulverized fuel-ash, is the residue of combustion of the finely ground coal used in the generation of electric power in coal-fired thermal power stations. Fly ash starts out as impurities in the coal used to fire electric power plants. These impurities can’t be burned. They melt and turn into tiny beads of glass that are carried up the flue and captured. Fly ash exits in a number of different chemistries and classes, but it is primarily the particle size that is important. ADVANTAGES OF SELF-COMPACTING CONCRETE The Advantages of SCC are • It eliminates noise due to vibration. • It provides high stability during transport and placement. • It provides uniform surface quality and homogenous. • It gives limited bleeding and settlement to reduce cracking and micro structural defects. • It provides greater freedom for design. • It is useful for casting of underwater structures. NEED FOR THE PRESENT WORK • The main property that defines SCC is highly workability in attaining consolidation and specified hardened prop-
The experimental program can be identified in two stages; first to develop SCC mixes for (M40 and M60) grades which different percentages of fine aggregate to total aggregate ratio using Nan Su method of mix design, which satisfies the fresh properties of SCC as per “EFNARC” specifications. To study the influence of various percentages of fine aggregate to total aggregate ratios for two different grades of concrete i.e., M40 and M60 on mechanical properties such as compressive strength, flexural strength and splitting tensile strength of concrete. The experimental program consisted of arriving at suitable mix proportions that satisfied the fresh properties of SCC as “EFNARC” specifications. Standard cubes of dimensions 150mm x 150mm x 150mm were caste to check whether the target compressive strength is achieved at 7-days and 28-days curing. If either the fresh properties or the strength properties are not satisfied, the mix is modified accordingly. Standard cube moulds of (150x150x150mm) made of cast iron were used for casting standard cubes. The standards moulds were fitted such that there are no gaps between the plates of the moulds. If there small gaps they were fitted with plaster of pairs. The moulds then oiled and kept ready for casting. After 24 hours of casting, the specimen were demoulded and transferred to curing tank where in they were immersed in water for the desired period of curing. MATERIALS USED The different materials used in this work are • 53 Grade ordinary Portland Cement • Fine Aggregate • Coarse Aggregate • Super Plasticizer (GLENIUM B233) • Viscosity modifying agent VMA (Stream-2) • Fly ash • Water This program consists of casting and testing of total 144 specimens. The specimens of standard cubes (150mm x 150mm x 150mm), standard cylinders of (150mm dia x 300mm height) and standard prisms of (100mm x 100mm x 500mm) were casted for 7 and 28 days for compressive strength, splitting tensile strength and flexural strength of concrete. TESTING OF SELF COMPACTING CONCRETE TESTING PROGRAM: (Initial test specifications) Properties of fresh Self Compacting Concrete (SCC) mixes must meet three key properties: 1. Ability to flow into and completely fill intricate and 184
International Journal of Research and Innovation (IJRI)
complex forms under its own weight 2. Ability to pass through and bond to congested reinforcement under its own weight. 3. High resistance to aggregate segregation.
• • • •
Due to the high content of powder, SCC may show more plastic shrinkage or creep than ordinary concrete mixes. These aspects should therefore be considered during designing and specifying SCC. Current knowledge of these aspects is limited and this is an area requiring further research. Special care should also be taken to begin curing the concrete as early as possible.
Procedure
The workability of SCC is higher than the highest class of consistence described within EN 206 and can be characterized by the properties like filling ability, passing ability and segregation resistance. Filling ability: Passing ability:
a) Slump flow test b) T50cm slump c) V-funnel test d) Orimet. a) L – Box b) U – Box c) J – ring d) Fill box
Segregation resistance:
Trowel Scoop ruler Stopwatch
• About 6 liter of concrete is needed to perform the test, sampled normally. Moisten the base plate and inside of slump cone, Place base plate on level stable ground and the slump cone centrally on the base plate and hold down firmly. • Fill the cone with the scoop. Do not tamp, simply strike off the concrete level with the top of the cone with the trowel. • Remove any surplus concrete from around the base of the cone. • Raise the cone vertically and allow the concrete to flow out freely. • Simultaneously, start the stopwatch and record the time taken for the concrete to reach the 500mm spread circle. (This is the T50 time). • Measure the final diameter of the concrete in two perpendicular directions. • Calculate the average of the two measured diameters. (This is the slump flow in mm).
a) GTM test b) V-funnel @ T5 min
Assessment of test This is a simple, rapid test procedure, though two people are needed if the T50 time is to be measured. It can be used on site, though the size of the base plate is somewhat unwieldy and level ground is essential. It is the most commonly used test, and gives a good assessment of filling ability. It gives no indication of the ability of the concrete to pass between reinforcement without blocking, but may give some indication of resistance to segregation. It can be argued that the completely free flow, unrestrained by any boundaries is not representative of what happens in practice in concrete construction, but the test can be profitably be used to assess the consistency of supply of ready-mixed concrete to a site from load to load.
Slump test
Slump flow equipment and measuring of slump flow
Equipment The apparatus is shown in figure • Mould in the shape of a truncated cone with the internal dimensions 200 mm diameter at the base, 100 mm diameter at the top and a height of 300 mm. • Base plate of a stiff non absorbing material, at least 900 x 900 mm square, marked with a circle marking the central location for the slump cone, and a further concentric circle of 500mm diameter.
Slump test concrete releasing
Interpretation of result The higher the slump flow (SF) value, the greater its ability to fill formwork under its own weight. A value of at least 650mm is required for SCC. There is no generally accepted advice on what are reasonable tolerances about a specified value, though ± 50mm, as with the related flow table test, might be appropriate. The result should be in between 650-800mm Obtained result from the sample is =680mm
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Assessment of test Though the test is designed to measure flow ability, the result is affected by concrete properties other than flow. The inverted cone shape will cause any liability of the concrete to block to be reflected in the result- if, for example there is too much coarse aggregate. High flow time can also be associated with low deformability due to a high paste viscosity, and with high inter-particle friction. While the apparatus is simple, the effect of the angle of the funnel and the wall effect on the flow of concrete is not clear.
U–box equipment
Funnel equipment
Concrete is filled position Funnel equipment concrete releasing time
U-Box opening the center gate
Interpretation of result Box equipment
If the concrete flows as freely as water, at rest it will be horizontal, so H1 - H2 = 0. Therefore the nearer this test value, the ‘filling height’, is to zero, the better the flow and passing ability of the concrete. U-box test should satisfy in between 15-30% Obtained test Result= 23%
Box concrete filling
Initial & Final setting test time Equipment
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Result: 1. Initial setting time of cement= 28 Mins 2. Final setting time of cement= 57 Mins
(a) Compressive strength test of cylindrical specimen (b) Compressive strength test of Cubic specimen
Compressive strength on cube
Casting and curing of test specimens The specimens of standard cubes (150mm x 150mm x 150mm), Standard prisms (100mm x 100mm x 500mm) and standard cylinders (150mm diameter x 300mm height) were casted. Mixing
Concrete is filling in Cubes
Measured quantities of coarse aggregate and fine aggregate were spread out over an impervious concrete floor. The dry ordinary Portland cement spread out on the aggregate and mixed thoroughly in dry state turning the mixture over and over until uniformity of color was achieved the time of mixing shall be 10-15 minutes. Placing and compacting The cube moulds shall be of 150mm size confirming to IS 10086-1982, the prism mould shall confirm to IS: 100861982 and cylinder moulds are cleaned, and all care was taken to avoid any irregular dimensions. The joints between the sections of mould were coated With mould oil and a similar coating of mould oil was applied between the contact surfaces of the bottom of the moulds and the base plate in order to ensure that no water escapes during the filling. The interior surfaces of the assembly moulds were thinly coated with mould oil to prevent adhesion of the concrete and for easy removal of moulds after casting. The mix was placed in moulds without compaction. Curing The test specimen cubes, prisms and cylinders were stored in a place, free from vibration, in most air at 90% relative humidity and at a temperature of 27 ±2c for 24 hours± ½ hour from the time of addition of water to the dry ingredients. After 24 hours the specimens were remolded and immediately immersed in clean, fresh water tank for a period of 7 and 28 days.
Compressive test equipment
MIX DESIGN Calculations of “Nan-Su” Mix Design Method (I). Mix design procedure for M40-Grade using “Nan Su” Method (FA/TA=55%) Quantity of Coarse aggregate (Qca) = P.F*Wca*(1-(S/a)) = 1.06*1560*(1-0.55) = 744.12 kg/m3 Quantity of Fine aggregate (Qfa) = P.F*Wfa*(S/a) = 1.06*1742*(0.55) = 1015.59 kg/m3 Quantity of Cement (Qc)
Quantity of Water (Qw)
= fck/0.14 = 48.25/0.14 = 344.64 kg/m3
= W/C*C = (0.55)*344.64 = 189.55 lit/m3
Compressive strength Mpa
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Volume of Fly ash (Vf) =1-(Qca/(1000*Sca))-(Qfa/ (1000*Sfa))(Qca/ (1000*Sc))- (Qw/ (1000*1))-Va = 0.002 m3
Adjustment of water quantity = (Qw) + (Qw-f) – (Qw-sp) = 189.55 + 1.05 – 2.081 = 188.53 kg/m3
Quantity of Fly ash (Qf) = 3.70 kg/m3
(III). Mix design procedure for M40-Grade using “Nan Su” Method (FA/TA=57%)
Water for fly ash (Qw-f) = 1.67 lit/m3 Quantity of Super Plasticizer (Qsp) = 1 %* (cement + fly ash) = 1/100*(344.64 + 3.70) = 3.48 lit/m3 Adjustment of mixing of water content in SCC (taking 60% of SP) = (1-0.4)*3.48 = 2.088 lit/m3 Quantity of V M A (Qvma) = 250*(cement + fly ash)/100 Taking 250 ml/100 kg
= 250*(344.64 + 3.70)/100 = 0.87 lit/m3
Adjustment of water quantity = (Qw) + (Qw-f) – (Qw-sp) = 189.55 + 1.67 – 2.088 = 189.13 kg/m3 (II). Mix design procedure for M40-Grade using “Nan Su” Method (FA/TA=56%) Quantity of Coarse aggregate (Qca) = P.F*Wca*(1-(S/a)) = 1.06*1560*(1-0.56) = 727.58 kg/m3 Quantity of Fine aggregate (Qfa) = P.F*Wfa*(S/a) = 1.06*1742*(0.56) = 1034.05 kg/m3 Quantity of Cement (Qc)
= fck/0.14 = 48.25/0.14 = 344.64 kg/m3
Quantity of Water (Qw) = W/C*C = (0.55)*344.64 = 189.55 lit/m3 Volume of Fly ash (Vf) = 1-(Qca/ (1000*Sca))-(Qfa/ (1000*Sfa))(Qca/ (1000*Sc))- (Qw/ (1000*1))-Va = 0.004 m3 Quantity of Fly ash (Qf) = 2.34 kg/m3 Water for fly ash (Qw-f) = 1.05 lit/m3 Quantity of Super Plasticizer (Qsp) = 1 %* (cement + fly ash) = 1/100*(344.64 + 2.34) = 3.46 lit/m3 Adjustment of mixing of water content in SCC (taking 60% of SP) = (1-0.4)*3.46 = 2.081 lit/m3 Quantity of V M A (Qvma) = 250*(cement + fly ash)/100 Taking 250 ml/100 kg
= 250*(344.64 + 2.34)/100 = 0.86 lit/m3
Quantity of Coarse aggregate (Qca) = P.F*Wca*(1-(S/a)) = 1.06*1560*(1-0.57) = 711.04 kg/m3 Quantity of Fine aggregate (Qfa) = P.F*Wfa*(S/a) = 1.06*1742*(0.57) = 1052.51 kg/m3 Quantity of Cement (Qc)
= fck/0.14 = 48.25/0.14 = 344.64 kg/m3
Quantity of Water (Qw)
= W/C*C = (0.55)*344.64 = 189.55 lit/m3
Volume of Fly ash (Vf) =1-(Qca/(1000*Sca))-(Qfa/ (1000*Sfa))(Qca/ (1000*Sc))- (Qw/ (1000*1))-Va = 0.001 m3 Quantity of Fly ash (Qf) = 0.98 kg/m3 Water for fly ash (Qw-f) = 0.44 lit/m3 Quantity of Super Plasticizer (Qsp) = 1 %* (cement + fly ash) = 1/100*(344.64 + 0.98) = 3.46 lit/m3 Adjustment of mixing of water content in SCC (taking 60% of SP) = (1-0.4)*3.46 = 2.078 lit/m3 Quantity of V M A (Qvma) = 250*(cement + fly ash)/100 Taking 250 ml/100 kg
= 250*(344.64 + 0.98)/100 = 0.86 lit/m3
Adjustment of water quantity = (Qw) + (Qw-f) – (Qw-sp) = 189.55 + 0.44 – 2.078 = 187.92 kg/m3 (IV). Mix design procedure for M40-Grade using “Nan Su” Method (FA/TA=58%) Quantity of Coarse aggregate (Qca) = P.F*Wca*(1-(S/a)) = 1.06*1560*(1-0.58) = 694.51 kg/m3 Quantity of Fine aggregate (Qfa) = P.F*Wfa*(S/a) = 1.06*1742*(0.58) = 1070.98 kg/m3 Quantity of Cement (Qc)
= fck/0.14 = 48.25/0.14 = 344.64 kg/m3
Quantity of Water (Qw) = W/C*C = (0.55)*344.64 = 189.55 lit/m3 188
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Volume of Fly ash (Vf) = 1-(Qca/ (1000*Sca))-(Qfa/ (1000*Sfa))(Qca/ (1000*Sc))- (Qw/ (1000*1))-Va = 0.001 m3 Quantity of Fly ash (Qf) = 0.68 kg/m3 Water for fly ash (Qw-f) = 0.44 lit/m3 Quantity of Super Plasticizer (Qsp) = 1 %* (cement + fly ash) = 1/100*(344.64 + 0.68) = 3.45 lit/m3 Adjustment of mixing of water content in SCC (taking 60% of SP) = (1-0.4)*3.45 = 2.071 lit/m3 Quantity of V M A (Qvma) Taking 250 ml/100 kg
(IV). Mix design procedure for M60-Grade using “Nan Su” Method (FA/TA=58%) Quantity of Coarse aggregate (Qca) = P.F*Wca*(1-(S/a)) = 1.06*1560*(1-0.58) = 694.51 kg/m3 Quantity of Fine aggregate (Qfa) = P.F*Wfa*(S/a) = 1.06*1742*(0.58) = 1070.98 kg/m3 Quantity of Cement (Qc)
= 250*(cement + fly ash)/100 = 250*(344.64 + 0.68)/100 = 0.86 lit/m3
Adjustment of water quantity = (Qw) + (Qw-f) – (Qw-sp) = 189.55 + 0.44 – 2.071 = 187.91 kg/m3 (I). Mix design procedure for M60-Grade using “Nan Su” Method (FA/TA=55%) Quantity of Coarse aggregate (Qca) = P.F*Wca*(1-(S/a)) = 1.06*1560*(1-0.55) = 744.12 kg/m3 Quantity of Fine aggregate (Qfa) = P.F*Wfa*(S/a) = 1.06*1742*(0.55) = 1015.59 kg/m3 Quantity of Cement (Qc)
Adjustment of water quantity = (Qw) + (Qw-f) – (Qw-sp) = 292.50 + 4.39 – 2.98 = 293.91 kg/m3
= fck/0.14 = 68.25/0.14 = 487.50 kg/m3
Quantity of Water (Qw) = W/C*C = (0.60)*487.50 = 292.50 lit/m3
= fck/0.14 = 68.25/0.14 = 487.50 kg/m3
Quantity of Water (Qw) = W/C*C = (0.60)*487.50 = 292.50 lit/m3 Volume of Fly ash (Vf) = 1-(Qca/ (1000*Sca))-(Qfa/ (1000*Sfa))(Qca/ (1000*Sc))- (Qw/ (1000*1))-Va = 0.002 m3 Quantity of Fly ash (Qf) = 9.68 kg/m3 Water for fly ash (Qw-f) = 4.19 lit/m3 Quantity of Super Plasticizer (Qsp) = 1 %* (cement + fly ash) = 1/100*(487.50 + 9.68) = 4.97 lit/m3 Adjustment of mixing of water content in SCC (taking 60% of SP) = (1-0.4)*4.97 = 2.98 lit/m3 Quantity of V M A (Qvma) Taking 250 ml/100 kg
= 250*(cement + fly ash)/100 = 250*(487.50 + 9.68)/100 = 1.24 lit/m3
Volume of Fly ash (Vf) = 1-(Qca/ (1000*Sca))-(Qfa/ (1000*Sfa))(Qca/ (1000*Sc))- (Qw/ (1000*1))-Va = 0.002 m3
Adjustment of water quantity = (Qw) + (Qw-f) – (Qw-sp) = 292.50 + 4.19 – 2.98 = 293.71 kg/m3
Quantity of Fly ash (Qf) = 9.75 kg/m3
COMPRESSION RESULTS OF FRIESH CONCRETE
Water for fly ash (Qw-f) = 4.39 lit/m3
Trial mixes of M40-GRADE (FA/TA=55%)
Quantity of Super Plasticizer (Qsp) = 1 %* (cement + fly ash) = 1/100*(487.50 + 9.75) = 4.97 lit/m3 Adjustment of mixing of water content in SCC (taking 60% of SP) = (1-0.4)*4.97 = 2.98 lit/m3 Quantity of V M A (Qvma) Taking 250 ml/100 kg
= 250*(cement + fly ash)/100 = 250*(487.50 + 9.75)/100 = 1.24 lit/m3
Variation of (M40-Grade) filling ability for FA/TA ratios
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Variation of (M40-Grade) passing ability for FA/TA ratios
Variation of (M40-Grade) segregation resistance for FA/TA ratios
Variation of (M60-Grade) segregation resistance for FA/TA ratios
Compressive strength for M-40 grade on cubes at (7 and 28 days)
Splitting tensile strength for M-40 grade on cylinders at (7 and 28 days) Variation of (M60-Grade) filling ability for FA/TA ratios
Compressive strength for M-60 grade on cubes at (7 and 28 days)
Variation of (M60-Grade) passing ability for FA/TA ratios
splitting tensile strength for M-60 grade on cylinders at (7 and 28 days)
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RESULTS AND DISCUSSIONS
“EFNARC” specifications.
DISCUSSIONS ON TEST RESULTS
• The fresh properties of SCC were satisfied when 40% of 20mm and 60% of 12mm size of coarse aggregates were used.
The discussions presented here are based on the results shown in the tables 4.9 to 4.14 and figures 4.1 to 4.14. • Mix proportions for M40 and M60 grade of self compacting concrete were developed using Nan Su method of mix design, which satisfied the fresh properties of SCC as per “EFNARC” specifications. • The fresh properties of SCC were satisfied when 40% of 20mm and 60% of 12mm size of coarse aggregates were used. • As the fine aggregate to total aggregate ratio increases from 55 to 58%, the fresh properties (i.e., filling ability, passing ability and segregation resistance) have been satisfied as per “EFNARC” specifications. • For both grades of concrete (i.e., M40 and M60), from table 4.13 and 4.14, figures 4.7 and 4.10 it is observed that the compressive strength of concrete is increased by increase in FA/TA ratio up to 57%, on further increase in the ratio i.e., 58%, the compressive strength for both grades of concrete is decreased. • Moreover from table 4.13 and 4.14 it is observed that the compressive strength of concrete is increased by 4.96% for M40 grade of concrete and 4.74% for M60 grade of concrete, when the FA/TA ratio was increased from 55 to 57%. And the compressive strength of concrete is decreased by 4.89% for M40 grade of concrete and 4.22% for M60 grade of concrete, when the FA/TA ratio was increased from 57 to 58%. • For both grades of concrete (i.e., M40 and M60), from table 4.13 and 4.14, figures 4.8 and 4.11 it is observed that the splitting tensile strength of concrete is increased by increase in FA/TA ratio up to 57%, on further increase in the ratio i.e., 58%, the splitting tensile strength for both grades of concrete is decreased. • Moreover from table 4.13 and 4.14 it is observed that the splitting tensile strength of concrete is increased by 12.79% for M40 grade of concrete and 8.30% for M60 grade of concrete, when the FA/TA ratio was increased from 55 to 57%. And the splitting tensile strength of concrete is decreased by 10.71% for M40 grade of concrete and 9.25% for M60 grade of concrete, when the FA/TA ratio was increased from 57 to 58%. • Grade of concrete, when the FA/TA ratio was increased from 57 to 58%. SUMMARY In this chapter the results and discussions are presented. Based on the discussions presented in this chapter the conclusions are given in next chapter. CONCLUSION & REFERENCES
• As the fine aggregate to total aggregate ratio increases from 55 to 58%, the fresh properties (i.e., filling ability, passing ability and segregation resistance) have been satisfied as per “EFNARC” specifications. • For both grades of concrete (i.e., M40 and M60), the compressive strength, splitting tensile strength and flexural strength of concrete is increased by increase in FA/ TA ratio up to 57%, on further increase in the ratio i.e., 58%, the compressive strength, splitting tensile strength and flexural strength for both grades of concrete is decreased. • The compressive strength of concrete is increased by 4.96% for M40 grade of concrete and 4.74% for M60 grade of concrete, when the FA/TA ratio was increased from 55% to 57%. • The compressive strength of concrete is decreased by 4.89% for M40 grade of concrete and 4.22% for M60 grade of concrete, when the FA/TA ratio was increased from 57% to 58%. • The splitting tensile strength of concrete is increased by 12.79% for M40 grade of concrete and 8.30% for M60 grade of concrete, when the FA/TA ratio was increased from 55% to 57%. • The splitting tensile strength of concrete is decreased by 10.71% for M40 grade of concrete and 9.25% for M60 grade of concrete, when the FA/TA ratio was increased from 57% to 58%. • The mechanical properties of SCC is not significantly affected by increased ratio of fine aggregate to total aggregate up to 57%, but it has been decreased when the ratio was further increased to 58%. SCOPE OF THE FUTURE WORK • Structural properties, Shrinkage characteristics, Creep characteristics of SCC can be investigated. REFERENCES • De Schutter .G (2005) “Guidelines for testing fresh Selfcompacting concrete” A journal of measurement of properties of fresh self compacting concrete. • “EFNARC” Specifications (2002) “Specification and guidelines for Self Compacting Concrete”. • Hajime Okamura and Mashaor Ouchi (2003), “Self-Compacting concrete” journal of Advanced Concrete Technology Vol.1, No.1, pp. 5-15, April 2003.
After the analysis of the results of the experimental program the following conclusions arrived.
• Hibino, M., Okamura, M., and Ozawa, K. (1998). “Role of Viscosity Modifying Agent in Self-Compatibility of Fresh Concrete”. Proceedings of the Sixth East-Asia Conference on Structural Engineering & Construction, 2, pp. 13131318.
• Mix proportions for M40 and M60 grade of self compacting concrete were developed using Nan Su method of mix design, which satisfied the fresh properties of SCC as per
• KAZUMASA OZAWA (1988), Domone et al (1999), and Gibbs et al (1999) “Self-Compacting concrete” journal of Advance Concrete Technology Vol.1, No.1,5-15, April
GENERAL
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(1999).
Author
• Nan Su - Cement and Concrete Composites 25 (2003) “A new method for mix design of medium strength flowing concrete with low cement concrete” pp. 215-222 • Nan Su, Kung-Chung H su and His Wen Chai (2001). “A Simple mix design method for Self Compacting Concrete” Cement and Concrete Research 31 (2001) 1799-1807. • Ouchi, M., Hibino, M., Sugamata, T., and Okamura, H. (2001). “A Quantitative Evaluation Method for the effect of Super plasticizer in Self Compacting Concrete”, Transactions of JCI, pp. 15-20. • Shetty M.S. (2006) Concrete Technology S.Chand & Company LTD
J.P.Alankruta Research Scholar, Department of Civil Engineering, Aurora's Scientific Technological and Research Academy, Bandlaguda,Hyderabad, India.
• Subramanya Chattopadhyay “Development of Self Compacting under water” ACI Materials Journal, V.96 No.3, May-June, pp. 346 • Khayat, K.H., (1999) “Workability, Testing and performance of Self consolidated Concrete” ACI Materials Journal, V.96 No.3, May-June, pp.346-352. • Su J.K., Cho S. W., Yang C. C. and Huang R (2002) “Effect of sand ratio on the elastic modulus of Self compacting concrete” Journal of marine science and technology, vol-10,No.1, pp. 8-13.
S.Uttamraj Assistant Professor, Department of Civil Engineering, Aurora's Scientific Technological and Research Academy, Bandlaguda,Hyderabad, India.
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