1 m3 concrete means that in 1 m3 concrete contained cement,sand and aggrigate with water.Mix together by mixer to produce 1 m3 of concrete.
How to calculate the volume or weight of every material in the concrete follow the ratio or grade.
Concrete has many grade from 15.20,25,30 and so on.Every grade of concrete have different ratio of material.Let say to calculate grade 20 of concrete.
Ratio 1:2;4 mean 1 part of cement 2 part of sand and 4 part of aggrigate.Caculate by weight
1m3 of concrete= 2400 kg,that mean for cement 1/7 x 2400 kg=328 kg of cement / 50= 7 bags of cement
For sand 2/7 x2400=660 kg of sand and for aggrigate 4/7 x2400 kg=1320 kg of aggrigate.
Grade 25:1:1.5:3
For cement 1/5.5 x 2400 kg=436.36 kg,sand =644 kg and aggrigate 1200 kg
For grade 30,ratio 1:1:3
For cement 1/5x2400kg=480 kg,sand=480 kg and aggrigate= 1440 kg
So from that calculation,cement part are the most important ingredient to get stronger grade for concrete
Water cement also important for binding,the cement ratio depending on the condition of exposured,take 0.55
Weight of water 0.55x328 for grade 20=165 kg
Caculation by volume,last time no ready mix and using site mixed,where got timbang to measure the weight of every materialbso use a volume calculation
For grade 20,cement 328/2400=0.136m3,sand=660/2400=0.0275 m3,aggrigate 1320/2400=0.55m3 and water 165/2400,=0.67m3,how to measure at site,Jkr method
Make a 300mmx300mmx300mm timber box,0.027m3,let say 50kg/2400 kg=0.0208m3+200kg/2400kg=0.042m3 and 0.083m3 of aggrigate
Cement= 1box
Sand=0.042/0.027=1.56 box
Aggrigate=165/2400/pail size to mix together in tne mixer about 15 minute before pouring.
Too difficult to recongnise a grade of concrete by visual only depending on delivery sheet and a 7 days of concrete cube result test.
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