Project on Concrete Mix Design for various grades of Concrete
MIX DESIGN FOR M35 GRADE WITH FLYASH
Stipulations
- Grade : M35
- Cement : OPC 43
- Max Nominal Size of Aggregates = 20mm
- Exposure Condition - Severe
- Method of Placing Pumping
- Chemical Admixture - Super Plasticizer
- Cemetitious Material - Fly Ash
- STEP 1 : TARGET STRENGTH
TARGET STRENGTH = Fck + 1.65 S = 35+1.65*5 ( S from IS code 10262 :2019)
= 43.25 N/mm2
STEP 2 : WATER CONTENT
From Table 2 of IS 10262:2019, Water content for Aggregate size 20 mm and Slump Value 25-50mm is 186 litres
Whereas the slump value here is 75 mm and we should increase the water content by 3 % for every 25mm increase in slump value
Therefore Water content = 186 + 186*3/100 = 192 Kg approx
Here we have superplasticizer as chemical admixture, therefore it reduces the water content upto 30%,
Water content = 192*0.7 = 134 litres
STEP 3 : CALCULATION OF CEMENT CONTENT
W/C FROM GRAPH IN IS CODE 10262: 2019 & EXPOSURE CONDITION IS 0.38 & 0.45 RESPECTIVELY CONSIDER THE LOWEST 0.38
W/C = 0.38 , CEMENT CONTENT = 134/0.38 = 352 KG
CEMENTITIOUS CONTENT = 352*1.10 = 387.2 KG
ABOUT 30% IS FLY ASH = 116 KG
CEMENT = 387-116 =271 KG/M3
W/C = 134/271 = 0.34
STEP 4 : COARSE AGGREGATE & FINE AGGREGATE VOLUME
FROM TABLE 3 IS 10262, FOR 20MM SIZE AGGREGATE, ZONE II, W/C = 0.6, NOW WE HAVE W/C = 0.34,
CA = 0.59 , FA = 0.41
MIX CALCULATIONS
- Vol of Concrete = 1 m3
- Vol of Cement = Mass/ Specific Gravity * 1/1000 = 271/3.10*1/1000 = 0.08 m3
- Vol of Flyash = 116/2.2*1/1000 =0.052 m3
- Vol of Water = 134/1000= 0.134 m3
- Vol of Chemical admixture =2% mass of cementatious material /Sp.Gr *1/1000 =7.74/1.1145*1/1000 =0.006 m3
- Volume of Aggregates = 1- 0.08-0.052-0.134-0.006=0.728 m3
- Mass of CA = 0.728 * 0.59*2.74*1000 = 1177 kg/m3
- Mass of FA = 0.728*0.41*2.74*1000 =818 kg/m3
Mix proportion = Mass of Cement : Mass of FA : Mass of Ca = 271:818:1177 = 1:3:4.34
MIX DESIGN FOR M50 GRADE WITHOUT FLYASH
Stipulations
- Grade : M50
- Cement : OPC 43
- Max Nominal Size of Aggregates = 20mm
- Exposure Condition - Severe
- Method of Placing Pumping
- Chemical Admixture - Super Plasticizers
STEP 1 : TARGET STRENGTH
TARGET STRENGTH = Fck + 1.65 S = 50+1.65*5 ( S from IS code 10262 :2019)
= 58.25 N/mm2
STEP 2 : WATER CONTENT
From Table 2 of IS 10262:2019, Water content for Aggregate size 20 mm and Slump Value 25-50mm is 186 litres
Whereas the slump value here is 75 mm and we should increase the water content by 3 % for every 25mm increase in slump value
Therefore Water content = 186 + 186*3/100 = 192 Kg approx
Here we have superplasticizer as chemical admixture, therefore it reduces the water content upto 30%,
Water content = 192*0.7 = 134 litres
STEP 3 : CALCULATION OF CEMENT CONTENT
W/C FROM GRAPH IN IS CODE 10262: 2019 & EXPOSURE CONDITION IS 0.38 & 0.45 RESPECTIVELY CONSIDER THE LOWEST 0.38
W/C = 0.38 , CEMENT CONTENT = 134/0.38 = 352 KG
W/C = 134/352 = 0.38
STEP 4 : COARSE AGGREGATE & FINE AGGREGATE VOLUME
FROM TABLE 3 IS 10262, FOR 20MM SIZE AGGREGATE, ZONE II, W/C = 0.6, NOW WE HAVE W/C = 0.38,
CA = 0.59 , FA = 0.41
MIX CALCULATIONS
- Vol of Concrete = 1 m3
- Vol of Cement = Mass/ Specific Gravity * 1/1000 = 352/3.10*1/1000 = 0.113 m3
- Vol of Water = 134/1000= 0.134 m3
- Vol of Chemical admixture =2% mass of cementatious material /Sp.Gr *1/1000 =7.04/1.1145*1/1000 =0.006 m3
- Volume of Aggregates = 1- 0.113-0.134-0.006=0.747 m3
- Mass of CA = 0.747 * 0.59*2.74*1000 = 1208 kg/m3
- Mass of FA = 0.747*0.41*2.74*1000 =840 kg/m3
Mix proportion = Mass of Cement : Mass of FA : Mass of Ca = 352:840:1208= 1:2.39:3.43