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CHAPTER 1INTRODUCTION11 Introduction of concreteConcrete is composite material containing cement Essay

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CHAPTER – 1INTRODUCTION1.1 Introduction of concreteConcrete is composite material containing cement, water, coarse aggregate and fine aggregate. The resulting material is a stone like structure which is formed by the chemical reaction of the cement and water. 1.2 Wastage of concreteDemolition of old and deteriorated building and traffic infrastructure, and their substitution with new ones, is a frequent phenomenon today in large part of the world. The main reason for this situation are changes of purpose, structural deterioration, rearrangement of a city and increasing traffic load, natural disasters (earthquake, fire, flood, etc.

).1.3 Wastage of concrete in IndiaIn India, The construction waste produced from building demolition alone is estimated to be 900 million tons per year. The most common method of managing this material has been through its disposal in landfills. On the other side when a building is demolished after its use, for repairs or for Fine aggregate is used to work according to IS : 383 Specification for coarse and fine aggregate from natural sources for concrete which fraction is from 4.

75 mm to 150 micron.Some basic test conducted on F.A. in laboratory. Which results are given below.Table 3.4 Sieve Analysis For Fine AggregateI.S. Sieve SizeWt. Retained on each sieve (gm)% Wt. Retained on each sieve Cumulative % wt. Retained on each sieve% passing4.75 mm282.82.897.22.36 mm11811.814.685.41.18 mm14514.529.170.9600 micron18718.747.852.2300 micron33433.481.218.8150 micron 1681.8982Pan 202Total 1000100273.5Fineness modulus for fine aggregate(cumulative % wt. Retained on each sieve)/(% wt. Retained on each sieve)2.74Specific Gravity of Fine Aggregate (IS : 2386-3 , 1963)PROCEDURE:To es (M2)g6106483Weight of saturated surface dry aggregates (M3)g5385824% water Absorption =(M3-M1)/M1*100%0.0760.1685% surface Moisture = (m2-M3)/M1*100%0.1450.1273.3 Coarse Aggregate (IS : 383)Coarse aggregate is used to work according to I.S. 383- Specifications for coarse aggregate and fine aggregate from natural sources for concrete which fraction is from 20mm to 4.75 mm.Some basic test conducted on C.A. in laboratory. Which results are given below.Specific Gravity of Coarse Aggregate (IS : 2386-3 , 1963)PROCEDURE:To determine the Specific Gravity of Coarse Aggregate, take bowl. After weight clean and dry bowl (W1). Place a sample of CA upto half of the bowl and weight (W2). Add Water to CA in bowl till its about half full. Mix thoroughly to remove entrapped air. Continue stirring and add more water till it is bowl with the graduated mark. Dry the outside and weight (W3). Empty the bowl, clean it refills with clean water flush with graduated mark wipe dry the outside and weight (W4).Fig. Specific Gravity of CATable 3.5 Specific Gravity of Coarse aggregateSr. No.DescriptionSample Number1Weight of empty bowl (M1)G4764762Weight of empty bowl + aggregate (M2)G147614763Weight of empty bowl + aggregate +water (M3)G 3372 33764Weight of bowl + water (M4)G 275427555Specific gravity = (M2-M1)/(M4-M1)-(M3-M2)2.612.636Avg. Sp. Gr.2.61DETERMINATION OF AGGREGATE IMPACT VALUE PROCEDURE:The Sr. No.DescriptionSample – ISample “II1Original weight of the aggregate passing through 12.5 mm IS sieve and retained on 10 mm IS sieve i.e. weight ->W13453552Weight of the aggregate passing through 2.36 mm IS sieve after the test i.e. weight -> W220313Weight of the aggregate retained on 2.36 mm IS sieve after the test i.e. weight ->W3 = W1 – W23233234W2 + W33433545Impact Value = W2 100 %W1Aggregate Impact Value = 7.26 %Flakiness Index PROCEDURE: The Wt. Of fraction consisting of at least 200 pieces (gm)Thickness gauge size (mm)Wt. Of aggregate in each fraction passing thickness gauge (gm)635026250-651705040122540-50286402562025-40103252082520-25422016108016-20631612.549012.5-164312.5101510-12.520106.32406.3-1015pan78total742Flakiness Index =(total wt. Of aggregate passing through various thickness gauge / total wt. Taken) x 10014.85Fig. Sieve analysis3.4 Recycled Coarse Aggregate Recycled Coarse aggregate is used to Sr. No.PropertyGrain size of NCAGrain size of RCA1Crushing resistance29.0% loss33.7% loss2Specific gravity kg/m32.612.373Water absorption after 30 min.0.4%2.87%4Bulk density, uncompacted kg/m3147012395Bulk density, Compacted kg/m3157013233.5 Water Water is an important ingredient of concrete as it actually participates in the chemical reaction with cement. Since it helps to from the strength giving cement gel, the quantity and quality of water are required to be looked into very carefully.3.5 Acid SolutionIn order to evaluate the degree of deterioration of two concrete mixes against accelerate Hydrochloric Acid, concrete cubes were immersed in 3% HCl acid solution and the pH was maintained 4.5 throughout. At 24 hr. of interval, difference in weight and change in compressive strength has been observed.3.6 MIX DESIGNMix design of M30 Grade of concreteStep ” 1 Stipulation for proportioning… a. Grade designation: M30 b. Types of cement:53 grade OPC c. Maximum nominal size of aggregate: 20 mm d. Maximum water cement ratio: 0.45 e. Workability: 75 mm f. Exposure condition : Mild g. Method of concrete placing: By hand h. Chemical Admixture : No i. Volume (by mass of cement): NoneStep ” 2 Test Data For Materials… j. Specific Gravity of cement : 3.15 k. Specific gravity of fine aggregate : 2.67 l. Specific gravity of coarse aggregate : 2.62 Step ” 3 Target strength for mix design… fck = fck + 1.65S = 31.6 N/mm2 Where, fck = target mean compressive strength Fck = characteristic compressive strength =30 N/mm2 S = standard deviation Step ” 4 Selection of water content…From IS:10260-2009 P-3 , T-2Maximum water content = 186 litreThis is for 20 mm max. Size aggregate and 50-75 mm slump,Water required after increase = 160 litreStep- 5 Calculation of Cement Content…Water cement ratio = 0.50Cement content = 380 kg/m3From IS : 456-2000 , P-20, T-5Minimum cement content for 300kg/m3 exposure condition = mild 380kg/m3>300kg/m3Step ” 6 Proportion of volume of coarse aggregate & fine aggregate…From IS:10262-2009, P-3, T-3,Volume of coarse aggregate corresponding to 20 mm size aggregate and fine aggregate (zone ” I) for water cement ratio 0.5=0.62In the our case water ” cement ratio = 0.5 , Therefore volume of C.A. is to be required to be increased to decreased the F.A. content.As the water cement ratio is lower by 0.1, the proportion of volume of C.A. is increased by 0.02. Therefore, corrected proportion of volume of coarse aggregate for the water cement ratio of 0.50 = 0.62Therefore, volume of C.A. = 0.62Volume of F.A. = 1- 0.62 = 0.38Step ” 7 mix calculation…A) volume of concrete = 1m3B) volume of cement = (mass of cement / sp.gr. of cement) x (1 / 1000) = 0.125 m3C) volume of water = (mass of water / sp.gr. of water) x (1 / 1000) = 0.160 m3D) Volume of all in aggregate = [a-(b + c+ d)] = 0.718 m3E) Mass of coarse aggregate :- = D x volume of C.A. x sp. Gr. Of C.A. X 1000 = 1283 KG f) Mass of fine aggregate :- = D x volume of F.A. x sp. Gr. Of F.A. X 1000 = 711 KGStep ” 8 Mix proportionsCement ” 380 kg/ m3 Water ” 160 litresFine Aggregate ” 711 kg/ m3Coarse Aggregate – 1283 kg/ m3Mix Design RatioCementWaterFACA10.421.873.37Table 3.10 Trial Mix Design Result Identification MarkAge of curingCube DimensionStrength (N/mm2)Avg. Strength (N/mm2)M-30_17 Days150 x 150 x 150 mm30.4331.18M-30_131.22M-30_131.843.7 Casting ScheduleIt is very important with respect to all properties of fresh as well as hardened concrete.First of all weighting and batching process of all ingredients of concrete such as Cement, Fine Aggregate, Coarse Aggregate, RCA and Water is done with higher accuracy before starting the mixing process. Then as per mix design it is to be mixed in the concrete mixture, First cement, aggregate by percentage and sand are mixed in the mixture for 2 to 3 minutes then add RCA by percentage as described in the mixture for 1 to 2 minutes and add water into it and mix it in proper way.Concrete’s strength mostly depends on the mix design. But it’s affected by several other factors. Such as mixing of concrete , placing of concrete, curing of concrete, as well as quality of concrete ingredients. So we can’t be assumed that if we produced that if we produce concrete as per mix design we will get desired strength.TESTIDETIFICATION MARKRCA%ADDED RCA CONCRETE7d28dCOMPRESSION STRENGTH(150X150X150 MM)Water curing onlyM-30_110%33M-30_110%33M-30_110%33M-30_2120%33M-30_2120%33M-30_2120%33M-30_3140%33M-30_3140%33M-30_3140%33Water curing + Acid attackM-30_110%33M-30_110%33M-30_110%33M-30_2120%33M-30_2120%33M-30_2120%33M-30_3140%33M-30_3140%33M-30_3140%33Table 3.11 SCHEDULE OF CASTINGTESTIDETIFICATION MARKRCA%ADDED RCA CONCRETE28dFLEXURE STRENGTH(150X150X600 MM)Water curing onlyM-30_110%3M-30_110%3M-30_110%3M-30_2120%3M-30_2120%3M-30_2120%3M-30_3140%3M-30_3140%3M-30_3140%3Water curing + Acid attackM-30_110%3M-30_110%3M-30_110%3M-30_2120%3M-30_2120%3M-30_2120%3M-30_3140%3M-30_3140%3M-30_3140%3 Table 3.12 SCHEDULE OF CASTING 3.8 Method of CastingProcedure of making concrete SpecimenMaking Concrete specimen such as cube for compressive strength, cylinder for splitting tensile strength and beam for flexural strength are simple and it’s done in three simple steps. 1. Cleaning & Fixing mould. 2. Placing, compacting & Finishing Concrete. 3. Curing.Cleaning & Fixing MouldClean the mould properly and apply oil on inner surface of mould. But no oil should be visible on surface. Fix the mould with base plate tightly. No gap should be left in joints so that cement slurry doesn’t penetrate. Place the mould level surfacePlacing, Compacting & finishing ConcretePreparation of concrete analogous to the traditional concrete. Drum Mixture have been accustomed prepare concrete. Mix of all the materials are exhausted the laboratory at temperature machine have been turned 3 to 5 min. Place the concrete into mould in layer. Compact each layer by giving 25 to 35 blows of tamping bar. Remove excess concrete from the top of mould and finish concrete surface with trowel. Make the top surface of concrete cube even and smooth. Left the mould completely undisturbed period, put down identification mark and casting date on the top of concrete specimen.CuringRemove the cube specimen from mould after 24 hours of casting. For removing Specimen From mould, first loosen all nut- bolts and carefully remove specimen because concrete is still lean weak and can be broken. Immediately after removing, put the specimen into a tank of clean water for curing. Make sure specimen is fully submerged in water. After 7 and 28 days of curing take out specimen from water tank and send to laboratory for testing.3.9 Method of TestingIn quality control concrete works, testing of hardened concrete plays an important role. The main purpose of testing hardened concrete is to confirm that the concrete used at site has developed described strength. Planned testing of cement, sand, aggregate, fresh concrete and hardened concrete is helpful in assuring the performance of the concrete with regard to both strength and durability of concrete.Testing for mechanical properties of hardened concrete A. Compressive Test B. Flexural TestTesting of hardened concrete plays an important role in controlling and confirming the quality of cement concrete works. Systematic testing of raw materials, fresh concrete and hardened concrete are inseparable part of any quality control programmed for concrete which helps to achieve higher efficiency of the materials used and greater assurance of the performance of the concrete with regard to both strength and durability.A) Compressive TestEvaluation of compressive strength of concrete specimen is carried by 2000 kN capacity hydraulic testing machine. According to IS: 516-1959 sample size of 150 x 150 x 150 mm for finding out The compressive strength of the sample. Below equation is used to finding out the compressive strength of the sample.Compressive Strength = P / AWhere, P = Compressive load at failure (kN) A = Cross ” sectional area of specimen (mm2)B) Flexural TestEvaluation of flexural strength of concrete specimen is carried by 250 kN capacity hydraulic testing machine. According to IS: 516 ” 1959 sample size of 100 x 100 x 600 mm for finding out The flexural strength of the sample. Below equation is used to finding out the flexural strength of the sample. Flexural Strength = PL / BD2 Where, P = Fracture load at beam (kN) L = Length of beam (mm) b = Width of beam (mm) d = Depth of beam (mm)CHAPTER – 6TESTING RESULT OF CONCRETEIn phase – 1 work M30 grade of concrete is casted and investigated compressive strength, splitting tensile strength, flexural strength and durability test are performed in laboratory.Result of M30 Grade of ConcreteFollowing various are conducted on concrete specimen and obtain results.Testing for mechanical properties of hardened concrete a. Compressive Test b. Flexure Test(KN).

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CHAPTER 1INTRODUCTION11 Introduction of concreteConcrete is composite material containing cement. (2019, Aug 20). Retrieved from https://studymoose.com/chapter-1introduction11-introduction-of-concreteconcrete-is-composite-material-containing-cement-essay

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