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2CEMENT CONCRETEMIX DESIGN
3Cement Concrete Mix Designmeans, determination of theproportion of the concreteingredients i.e. Cement, Water,Fine Aggreg...
4Methods of Concrete Mix Design• I.S. Method• British Method• A.C.I. Method etc.
5These Methods are based on twobasic assumptionsCompressive Strength ofConcrete is governed by itsWater-Cement RatioWorkab...
6Data required for concrete mixdesign1. Grade of ConcreteEg: RCC-M30-A202. Slump required in mmEg: 25 – 75 mm3. Degree of ...
7Placing Conditions Degree of Workability Slump(mm)1 2 3Blinding Concrete;Shallow Sections;Pavements using paversVery Low ...
8GoodSite control having proper storage ofcement;weigh batching of all materials;Controlled addition of water,regular chec...
9Sl.No.Environment Exposure Conditions1 2 3i) MildConcrete surfaces protectedagainst weather or aggressive conditions,exce...
10Approximate Quantity of Materialsrequired for concrete mix design1. Cement : 200 Kg.2. Fine Aggregate : 240 Kg.3. Coarse...
11STEPS INVOLVED IN CONCRETE MIX DESIGN Step I:- Determine the physical properties ofconcrete ingredients.I. CEMENT (OPC ...
12Sieve Size % Passing Specifications for Zone–IIAs per IS:383-197010.0 mm 100 1004.75 mm 100 90-1002.36 mm 98 75-1001.18 ...
13Sieve Size % Passing SpecificationsAs per IS:383-1970Graded Single Sized40.00mm 100 100 10020.00mm 90 95-100 85-10010.00...
14Sl.No.Particulars of Test Result SpecificationsAs per IS: 383-19701 Crushing Value in % 28 30 MaximumFor wearing surface...
15Sieve Size % Passing SpecificationsAs per IS:383-1970Graded Single Sized12.50mm 100 – 10010.00mm 85 – 85-1004.75mm 19 – ...
16VI. BLENDING OF COARSE AGGREGATE:Sievesize(mm)IS:383-1970Specifications(Graded)% Passing20 mm 10 mm 60%+40% 50%+50%40 10...
17 Step II:- Compute Target Mean Compressive Strength:Fck = fck + t * SFck = Target Mean Compressive Strength at 28 days ...
18Values of tAccepted proportionof low resultst1 in 5, 20% 0.841 in 10, 10% 1.281 in 15, 6.7% 1.501 in 20, 5% 1.651in 40, ...
19Assumed Standard Deviation(Table 8, IS:456-2000)Grade ofConcreteAssumed Standard Deviation(N/Sq.mm)Good Site Control Fai...
20 Step III:- Select the Water-Cement ratio of trial mix fromexperienceS.No.ConcreteGradeMinimum expected W/C1 M10 0.92 M...
21 Step IV:- Select the water content per cubic metre ofconcrete from table2 of I.S: 10262-2009.Maximum size ofAggregate(...
22Approximate water content (Kg)per cubic metre of concrete(Table 32, SP:23-1982)Slump(mm)Maximum Size ofAggregate(mm)10 2...
23Volume of Coarse Aggregate perUnit Volume of Total Aggregate(Table 3, IS:10262-2009)MaximumSize ofAggregate(mm)Volume of...
24
25 Step V:- Compute the quantity of cement as follows.WaterCement = -------------W/C Ratio= 185 / 0.45 = 411 Kg.
26Step VI:- Then we find the quantities of Fine & Coarseaggregate by absolute volume method.V = (W+C/Sc+(1/p) * (fa/Sfa)) ...
27Substituting the values in Eq(1), we get1000 = 185 + 411/3.0 + (1/0.36) * fa /2.6)= 185 + 137 + fa/0.936= 322 + fa/0.936...
28Substituting the values in Eq(2), we get1000 = 185 + 411/3.0 + (1/0.64) * ca /2.65)= 185 + 137 + ca/1.696= 322 + ca/1.69...
29So the mix proportion works out to beW : C : fa : ca= 185 : 411 : 635 : 1150= 0.45 : 1 : 1.55 : 2.80This mix will be con...
30 Step VII:- Make slump trials to find out the actual weight of waterto get required slump. Make corrections to the wate...
31Trial Mix No. 1:-Cement = 185 / 0.4 = 462.5 Kg.Substituting the values in Eq(1), we get1000 = 185 + 462.5/3.0 + (1/0.34)...
32Trial Mix No. 3:-Cement = 185 / 0.5 = 370 Kg.Substituting the values in Eq(1), we get1000 = 185 + 370/3.0 + (1/0.38) * f...
33 Step IX:- Cast atleast 3 cubes for each trial mix. Step X:- Test the cubes for compressive strength at 28 days.
3428 Days Compressive Strengths of Trial MixesW/CRatioC/W RatioCompressiveStrength(Kg/Cm2)0.40 2.50 4570.45 2.22 4200.50 2...
35 Step XI:- Draw a graph between compressive strength Vs C/W Ratio.
36
37 Step XII:- From the graph, find the W/C ratio for the requiredtarget mean compressive strength. Step XIII:- Calculate...
38Final Mix:-From the graph, for a target strength of 390 Kg/Cm2, W/C ratio = 0.47Cement = 185 / 0.47 = 394 Kg.Substitutin...
39 Step XIV:- Check the cement content & W/C ratio against thelimiting values given in Table-5 ofI.S: 456-2000 for given ...
40Table-5 Minimum Cement content Maximum Water-Cementratio and Minimum Grade of Concrete for different exposureswith norma...
41From the table 5 of IS: 456–2000, the minimum Cement content& W/C ratio, For moderate, for RCC are 300Kgs. & 0.5The Ceme...
42TEST REPORTConcrete Mix RCC M30 with 20.0mm M.S.A.Sl.No.Particulars Result1 Characteristic Compressive strength inN/Sq.m...
43• Secondary Slides:
44Sieve Analysis of Fine Aggregate•Weight of sample = 500g (approx)•Observations:SievesizeWeight retained(g)Cumulativeweig...
45Zones of Fine AggregateSieve SizeIS : 383 – 1970% Passing forZone I Zone II Zone III Zone IV10.00 mm 100 100 100 1004.75...
46Sieve Analysis of Coarse Aggregate2 20 mm aggregate :a.       Minimum weight of sample = 25 Kgb.      Observations :Siev...
47Sieve Analysis of Coarse Aggregate2 10 mm aggregate :a.       Minimum weight of sample = 12 Kgb.      Observations :Siev...
48N = 20 N = 20Avg = 30 Avg = 3527,30,30,32,35,27,33,34,29,28,30,28,31,32,26,34,33,25,27,2928, 32,35,38,40,34,35,35,36,39,...
49The value of ‘S’ depends on Degree of Site controland grade of concrete as given in I.S: 456–2000 (Table.8)Sl.No.Concret...
50 Step IV:-Fixation of Water Cement ratios for trial mixes.Sl.No.Required GradesTrial W/C1 M20, M15, M10 0.55, 0.6, 0.92...
51Final Mix for RCC-M25:-From the graph, for a target strength of 322 Kg/Cm2, W/C ratio = 0.57which is > 0.5, So, limit W/...
52Specific Gravity of Cement [ IS : 4031 – 1988]:Specific gravity of cement (Sc)(W2 - W1)= ---------------------------- x ...
53Specific Gravity of Fine Aggregate & Coarse Aggregate [ IS : 2386 (Part.3) - 1963]:DSpecific gravity (Gs) = ------------...
54
55
Concrete mix design
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Concrete mix design

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Concrete mix design

  1. 1. 2CEMENT CONCRETEMIX DESIGN
  2. 2. 3Cement Concrete Mix Designmeans, determination of theproportion of the concreteingredients i.e. Cement, Water,Fine Aggregate,Coarse Aggregatewhich would produce concretepossessing specified propertiessuch as workability, strength anddurability with maximum overalleconomy.
  3. 3. 4Methods of Concrete Mix Design• I.S. Method• British Method• A.C.I. Method etc.
  4. 4. 5These Methods are based on twobasic assumptionsCompressive Strength ofConcrete is governed by itsWater-Cement RatioWorkability of Concrete isgoverned by its Water Content
  5. 5. 6Data required for concrete mixdesign1. Grade of ConcreteEg: RCC-M30-A202. Slump required in mmEg: 25 – 75 mm3. Degree of Site ControlEg: Good4. Type of ExposureEg: Moderate5. Grade of CementEg: OPC 43 Grade
  6. 6. 7Placing Conditions Degree of Workability Slump(mm)1 2 3Blinding Concrete;Shallow Sections;Pavements using paversVery Low See 7.1.1Mass Concrete;Lightly reinforced sections in Slabs,Beams, Walls, Columns; Floors;Hand placed Pavements;Canal lining; Strip FootingsLow 25-75Heavily reinforced sections in Slabs,Beams, Walls, Columns;Slip form work; Pumped Concrete.Medium 50-100Trench fill; In-Situ Piling; TremieConcreteHigh 100-150
  7. 7. 8GoodSite control having proper storage ofcement;weigh batching of all materials;Controlled addition of water,regular checking of all materials,aggregate grading and moisturecontent;And periodical checking ofworkability and strength.Fair Site control having deviation from theabove.
  8. 8. 9Sl.No.Environment Exposure Conditions1 2 3i) MildConcrete surfaces protectedagainst weather or aggressive conditions,except those situated in coastal area.ii) ModerateConcrete surfaces sheltered from severe rain or freezingwhilst wet.Concrete exposed to condensation and rain.Concrete continuously under water.Concrete in contact or buried under non-aggressivesoil/ground water.Concrete surfaces sheltered from saturated salt air incoastal area.iii) SevereConcrete surfaces exposed to severe rain, alternatewetting and drying or occasional freezing whilst wet orsevere condensation.Concrete completely immersed in sea water.Concrete exposed to coastal environment.iv) Very SevereConcrete exposed to sea water spray, corrosive fumes orsevere freezing conditions whilst wet.Concrete in contact with or buried under aggressivesub-soil/ground water.v) ExtremeSurface of members in tidal zone.Members in direct contact with liquid/solid aggressivechemicals.
  9. 9. 10Approximate Quantity of Materialsrequired for concrete mix design1. Cement : 200 Kg.2. Fine Aggregate : 240 Kg.3. Coarse Aggregate : 180 Kg. (20 mm)180 Kg. (10 mm)
  10. 10. 11STEPS INVOLVED IN CONCRETE MIX DESIGN Step I:- Determine the physical properties ofconcrete ingredients.I. CEMENT (OPC 43 Grade)Sl.No.Particulars of Test Result SpecificationsAs per IS:8112-19761 Standard consistency(% by weight)25.62 Setting Time in minutesa) Initialb) Final9521030 Minimum600 Maximum3 Compressive Strength inN/sq.mm at the age ofa) 3 daysb) 7 daysc) 28 days24354623 Minimum33 Minimum43 Minimum4 Specific Gravity 3.005 Fineness in Sq.m/Kg 337 225 Minimum
  11. 11. 12Sieve Size % Passing Specifications for Zone–IIAs per IS:383-197010.0 mm 100 1004.75 mm 100 90-1002.36 mm 98 75-1001.18 mm 65 55-90600 micron 42 35-59300 micron 8 8-30150 micron 0 0-10II. FINE AGGREGATE1. Sieve Analysis2. Specific Gravity : 2.603. Unit Weight in Kg/Cu.ma) Loose : 1460b) Rodded : 15804. Materials Finer than 75 micron : 1.00 3 Max(% by weight)
  12. 12. 13Sieve Size % Passing SpecificationsAs per IS:383-1970Graded Single Sized40.00mm 100 100 10020.00mm 90 95-100 85-10010.00mm 3 25-55 0-204.75mm 0 0-10 0-5III. 20.0mm COARSE AGGREGATE1. Sieve Analysis2. Specific Gravity : 2.653. Unit Weight in Kg/Cu.ma) Loose : 1467b) Rodded : 1633
  13. 13. 14Sl.No.Particulars of Test Result SpecificationsAs per IS: 383-19701 Crushing Value in % 28 30 MaximumFor wearing surfaces45 MaximumFor other concrete2 Impact Value in % 24 30 MaximumFor wearing surfaces45 MaximumFor other concrete3 Los Angeles AbrasionValue in %30 30 MaximumFor wearing surfaces50 MaximumFor other concreteIV. MECHANICAL PROPERTIES
  14. 14. 15Sieve Size % Passing SpecificationsAs per IS:383-1970Graded Single Sized12.50mm 100 – 10010.00mm 85 – 85-1004.75mm 19 – 0-202.36mm 0 – 0-5V. 10.0mm COARSE AGGREGATE1. Sieve Analysis2. Unit Weight in Kg/Cu.ma) Loose : 1427b) Rodded : 1587
  15. 15. 16VI. BLENDING OF COARSE AGGREGATE:Sievesize(mm)IS:383-1970Specifications(Graded)% Passing20 mm 10 mm 60%+40% 50%+50%40 100 100 100 100 10020 95-100 90 100 94 9510 25-55 3 85 40 444.75 0-10 0 19 7 10
  16. 16. 17 Step II:- Compute Target Mean Compressive Strength:Fck = fck + t * SFck = Target Mean Compressive Strength at 28 days inN/Sq.mmfck = Characteristic Compressive Strength at 28 days inN/Sq.mmS = Standard Deviation in N/Sq.mmt = A Statistic, depending on accepeted proportion oflow results.= 1.65 for 1 in 20 accepted proportion of lowresults
  17. 17. 18Values of tAccepted proportionof low resultst1 in 5, 20% 0.841 in 10, 10% 1.281 in 15, 6.7% 1.501 in 20, 5% 1.651in 40, 2.5% 1.861 in 100, 1% 2.33
  18. 18. 19Assumed Standard Deviation(Table 8, IS:456-2000)Grade ofConcreteAssumed Standard Deviation(N/Sq.mm)Good Site Control Fair Site ControlM10, M15 3.5 4.5M20, M25 4.0 5.0M30, M35M,40,M45M505.0 6.0
  19. 19. 20 Step III:- Select the Water-Cement ratio of trial mix fromexperienceS.No.ConcreteGradeMinimum expected W/C1 M10 0.92 M15 0.73 M20 0.554 M25 0.505 M30 0.456 M35 0.407 M40 0.358 M45 0.30
  20. 20. 21 Step IV:- Select the water content per cubic metre ofconcrete from table2 of I.S: 10262-2009.Maximum size ofAggregate(mm)Water Content percubic metre ofconcrete(Kg)10 20820 18640 165
  21. 21. 22Approximate water content (Kg)per cubic metre of concrete(Table 32, SP:23-1982)Slump(mm)Maximum Size ofAggregate(mm)10 20 4030-50 205 185 16080-100 225 200 175150-180 240 210 185
  22. 22. 23Volume of Coarse Aggregate perUnit Volume of Total Aggregate(Table 3, IS:10262-2009)MaximumSize ofAggregate(mm)Volume of Coarse Aggregate per UnitVolume of Total AggregateZone IV Zone III Zone II Zone I10 0.50 0.48 0.46 0.4420 0.66 0.64 0.62 0.6040 0.75 0.73 0.71 0.69
  23. 23. 24
  24. 24. 25 Step V:- Compute the quantity of cement as follows.WaterCement = -------------W/C Ratio= 185 / 0.45 = 411 Kg.
  25. 25. 26Step VI:- Then we find the quantities of Fine & Coarseaggregate by absolute volume method.V = (W+C/Sc+(1/p) * (fa/Sfa)) * (1/1000) - (Eq.1)andV = (W+C/Sc+(1/(1-p)) * (ca/Sca)) * (1/1000) - (Eq.2)WhereV = Absolute volume of fresh concrete = 1 m3W = Mass of Water (Kg) per m3of concreteC = Mass of Cement (Kg) per m3ofconcretep = Percentage of fine aggregate.fa = Mass of fine aggregateca = Mass of coarse aggregateSc = Specific gravity of cement.Sfa = Specific gravity of fine aggregate.Sca = Specific gravity of coarse aggregate.
  26. 26. 27Substituting the values in Eq(1), we get1000 = 185 + 411/3.0 + (1/0.36) * fa /2.6)= 185 + 137 + fa/0.936= 322 + fa/0.936fa = (1000 – 322) * 0.936= 678 * 0.936= 635 Kg.
  27. 27. 28Substituting the values in Eq(2), we get1000 = 185 + 411/3.0 + (1/0.64) * ca /2.65)= 185 + 137 + ca/1.696= 322 + ca/1.696ca = (1000 – 322) * 1.696= 678 * 1.696= 1150 Kg.
  28. 28. 29So the mix proportion works out to beW : C : fa : ca= 185 : 411 : 635 : 1150= 0.45 : 1 : 1.55 : 2.80This mix will be considered as Trial Mix No.2
  29. 29. 30 Step VII:- Make slump trials to find out the actual weight of waterto get required slump. Make corrections to the watercontent & %FA, if required. Step VIII:- Compute 2 more trial mixes with W/C ratios as 0.40 &0.50, taking %FA as 34% and 38% respectively.
  30. 30. 31Trial Mix No. 1:-Cement = 185 / 0.4 = 462.5 Kg.Substituting the values in Eq(1), we get1000 = 185 + 462.5/3.0 + (1/0.34) * fa /2.6)fa = 584 Kg.Substituting the values in Eq(2), we get1000 = 185 + 462.5/3.0 + (1/0.66) * ca /2.65)ca = 1156 Kg.So the mix proportion works out to beW : C : fa : ca= 185 : 462.5 : 584 : 1156= 0.4 : 1 : 1.26 : 2.50
  31. 31. 32Trial Mix No. 3:-Cement = 185 / 0.5 = 370 Kg.Substituting the values in Eq(1), we get1000 = 185 + 370/3.0 + (1/0.38) * fa /2.6)fa = 683 Kg.Substituting the values in Eq(2), we get1000 = 185 + 370/3.0 + (1/0.62) * ca /2.65)ca = 1136 Kg.So the mix proportion works out to beW : C : fa : ca= 185 : 370 : 683 : 1136= 0.5 : 1 : 1.85 : 3.07
  32. 32. 33 Step IX:- Cast atleast 3 cubes for each trial mix. Step X:- Test the cubes for compressive strength at 28 days.
  33. 33. 3428 Days Compressive Strengths of Trial MixesW/CRatioC/W RatioCompressiveStrength(Kg/Cm2)0.40 2.50 4570.45 2.22 4200.50 2.00 360
  34. 34. 35 Step XI:- Draw a graph between compressive strength Vs C/W Ratio.
  35. 35. 36
  36. 36. 37 Step XII:- From the graph, find the W/C ratio for the requiredtarget mean compressive strength. Step XIII:- Calculate the mix proportions corresponding tothe W/C ratio, obtained from the graph.
  37. 37. 38Final Mix:-From the graph, for a target strength of 390 Kg/Cm2, W/C ratio = 0.47Cement = 185 / 0.47 = 394 Kg.Substituting the values in Eq(1), we get1000 = 185 + 394/3.0 + (1/0.38) * fa /2.6)fa = 675 Kg.Substituting the values in Eq(2), we get1000 = 185 + 394/3.0 + (1/0.62) * ca /2.65)ca = 1123 Kg.So the mix proportion works out to beW : C : fa : ca= 185 : 394 : 675 : 1123= 0.47 : 1 : 1.71 : 2.85
  38. 38. 39 Step XIV:- Check the cement content & W/C ratio against thelimiting values given in Table-5 ofI.S: 456-2000 for given type of exposure & type of Concrete.
  39. 39. 40Table-5 Minimum Cement content Maximum Water-Cementratio and Minimum Grade of Concrete for different exposureswith normal weight of aggregate of 20mm nominal maximumsize.Sl.No.ExposurePlain Concrete Reinforced ConcreteMinimumCementContentkg/m3MaximumFreeWaterCementRatioMinimumGrade ofConcreteMinimumCementContentkg/m3MaximumFreeWaterCementRatioMinimumGrade ofConcretei) Mild 220 0.60 - 300 0.55 M20ii) Moderate 240 0.60 M15 300 0.50 M25iii) Severe 250 0.50 M20 320 0.45 M30iv) VerySevere260 0.45 M20 340 0.45 M35v) Extreme 280 0.40 M25 360 0.40 M40
  40. 40. 41From the table 5 of IS: 456–2000, the minimum Cement content& W/C ratio, For moderate, for RCC are 300Kgs. & 0.5The Cement content = 394Kgs. > 300Kgs. Hence OkThe W/C Ratio = 0.47 < 0.5 Hence Ok
  41. 41. 42TEST REPORTConcrete Mix RCC M30 with 20.0mm M.S.A.Sl.No.Particulars Result1 Characteristic Compressive strength inN/Sq.mm302 Maximum size of Aggregate in mm 20.03 Type of Exposure Moderate4 Type of Site control Good5 Target Average Compressive Strength inN/Sq.mm38.26 Workability in terms of Slump in mm 25-757 Mode of Compaction Vibration8 Mix Partiuclars:a. Water-Cement Ratiob. Materials per cubic metre of concrete inKg.i) Waterii) Cement (OPC 43 Grade)iii) Fine Aggregateiv) Coarse Aggregatec. Mix Portion by weight0.4718539467511231:1.71:2.85
  42. 42. 43• Secondary Slides:
  43. 43. 44Sieve Analysis of Fine Aggregate•Weight of sample = 500g (approx)•Observations:SievesizeWeight retained(g)Cumulativeweightretained (g)%Cumulativeweightretained (g)%PassingIS:383-1970SpecificationsZone =IITrail 1 Trail2 Total10 mm 0 0 0 0 0 100 1004.75 mm 2 2 4 4 0 100 90-1002.36 mm 6 7 13 17 2 98 75-1001.18 mm 166 165 331 348 35 65 55-90600 micron 118 117 235 583 58 42 35-59300 micron 175 160 335 918 92 8 8-30150 micron 36 42 78 996 100 0 0-10150 micron pass 2 2 4 - - - -
  44. 44. 45Zones of Fine AggregateSieve SizeIS : 383 – 1970% Passing forZone I Zone II Zone III Zone IV10.00 mm 100 100 100 1004.75 mm 90-100 90-100 90-100 95-1002.36 mm 60-95 75-100 85-100 95-1001.18 mm 30-70 55-90 75-100 90-100600 micron 15-34 35-59 60-79 80-100300 micron5-20 8-30 12-40 15-50150 micron 0-10 0-10 0-10 0-15
  45. 45. 46Sieve Analysis of Coarse Aggregate2 20 mm aggregate :a.       Minimum weight of sample = 25 Kgb.      Observations :SievesizeWeightretained(Kg)Cumulativeweightretained(Kg)%Cumulativeweightretained(Kg)%PassingIS:383-1970SpecificationsGradedSinglesized40 0.0 0.0 0 100 100 10020 4.7 4.7 10 90 95-100 85-10010 41.546.297 3 25-55 0-204.75 1.6 47.8 100 0 0-10 0-54.75 P 0 47.8 - - - -
  46. 46. 47Sieve Analysis of Coarse Aggregate2 10 mm aggregate :a.       Minimum weight of sample = 12 Kgb.      Observations :SievesizeWeightretained(Kg)Cumulativeweightretained(Kg)%Cumulativeweightretained(Kg)%PassingIS:383-1970SpecificationsSingleSized12.5 0.0 0.0 0 100 10010 5.4 5.4 15 85 85-1004.75 24.329.781 19 0-202.36 6.9 36.6 100 0 0-52.36 P 0 36.6 - - - -
  47. 47. 48N = 20 N = 20Avg = 30 Avg = 3527,30,30,32,35,27,33,34,29,28,30,28,31,32,26,34,33,25,27,2928, 32,35,38,40,34,35,35,36,39,33,32,32,34,37,32,35,38,39,36Total = 600 Total = 700Target mean compressive strength
  48. 48. 49The value of ‘S’ depends on Degree of Site controland grade of concrete as given in I.S: 456–2000 (Table.8)Sl.No.ConcreteGradeGood FairS 1.65XSFckS 1.65XSFckN/mm2Kg/cm2N/mm2Kg/cm21 M10 3.5 58 15.8 161 4.5 7.4 17.4 1782 M15 3.5 58 20.8 212 4.5 7.4 22.4 2293 M20 4.0 6.6 26.6 271 5.0 8.3 28.3 2884 M25 4.0 6.6 31.6 322 5.0 8.3 33.3 3395 M30 5.0 8.3 38.3 390 6.0 9.9 39.9 4076 M35 5.0 8.3 43.3 441 6.0 9.9 44.9 458
  49. 49. 50 Step IV:-Fixation of Water Cement ratios for trial mixes.Sl.No.Required GradesTrial W/C1 M20, M15, M10 0.55, 0.6, 0.92 M25, M20, M15 0.5, 0.6, 0.7
  50. 50. 51Final Mix for RCC-M25:-From the graph, for a target strength of 322 Kg/Cm2, W/C ratio = 0.57which is > 0.5, So, limit W/C ratio to 0.5 only.Cement = 185 / 0.5 = 370 Kg.Substituting the values in Eq(1), we get1000 = 185 + 370/3.0 + (1/0.38) * fa /2.6)fa = 683 Kg.Substituting the values in Eq(2), we get1000 = 185 + 370/3.0 + (1/0.62) * ca /2.65)ca = 1136 Kg.So the mix proportion works out to beW : C : fa : ca= 185 : 370 : 683 : 1136= 0.50 : 1 : 1.85 : 3.07
  51. 51. 52Specific Gravity of Cement [ IS : 4031 – 1988]:Specific gravity of cement (Sc)(W2 - W1)= ---------------------------- x 0.79(W4 - W1) - (W3 - W2)Where,W1 = Weight of specific gravity bottle in gW2 = Weight of specific gravity bottle with about half filled cement in gW3 = Weight of specific gravity bottle with about half filled cement& rest is filled with kerosene in g.W4 = Weight of specific gravity bottle completely filled with kerosene in g0.79 = Specific Gravity of Kerosene.
  52. 52. 53Specific Gravity of Fine Aggregate & Coarse Aggregate [ IS : 2386 (Part.3) - 1963]:DSpecific gravity (Gs) = --------------C – ( A – B)Where,A = Weight of Pycnometer vessel containing sample & filled with distilled water in gB = Weight of Pycnometer completely filled with distilled water only in gC = Weight of saturated surface dry sample in gD = Weight of oven dried sample in g
  53. 53. 54
  54. 54. 55

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