# Material consumption for Concrete

Do you know how happy am I today ?

One of my students has asked me this question through  a web site

Oh, its quite simple. That student shall have his required answer and as a bonus , I am having this blog post which I can present to you . You can also go through this .

———————————————————————————————————————————————-

Thank you sir ! anticipating lot of guidance..

1 question.. If on site for 900 cft slab casting material ratio is M20 as per drawing but mixing on site is 3 tagari cement=1 bag of cement.. 6 tagari of sand… 7 tagari of aggregate. .
How to estimate how much cement sand aggregate required on such base (on tagari base 1:6:7) for 900 cft or in cum.. Looking forward for your response. .Thank u.

————————————————————————————————————————————————————Solution :

Data :
1.Volume of the slab : 900 Cft  .= 900/ 35.29 = 25.50 CuM.
2. Mix of concrete : M20
3. Actual mix at site :
1 bag of cement : 6 tagari of sand. : 7 tagari of aggregate.

4. 1 bag of cement = 3 tagari
5.Actual ratio at site :
3 tagari : 6 tagari : 7 tagari
or , it can be written as :
3/3 :6/3 :7/3
or 1 : 2 : 2.33
6. Actual nominal mix at site : 1 : 2 : 2.33
7. Let is first calculate the cement , sand and aggregate required for 1 CuM of Concrete.
8. By dry mix method ,

Cement = 1.52 *28.8 /( 1 : 2 : 2.33) = 8.21 Bags
Sand = 0.3529 * 1.52 *2 /( 1 : 2 : 2.33) = 0.201 Brass of sand
Aggregate = 0.3529 * 1.52 *2.33 /( 1 : 2 : 2.33) = 0.234 Brass of Aggregate

9. Material constants :
Cement = 8.21 Bags
Sand =    0.201 Brass of sand
Aggregate = 0.234 Brass of Aggregate

10.Material consumption for 25.5 CuM ( 900 Cft ) of concrete :

Cement = 8.21*25.5 Bags = 209.36 Bags
Sand = 0.201*25.5 Brass of sand = 5.13 Brass
Aggregate = 0.234*25.5 Brass of Aggregate = 5.97 Brass