Question

7. Initial and final set of cement occurs during:

1. Stage I(b) Stage II(c) Stage III(d) Stage IV

8. A sample of aggregate has a moisture content of 8%. Its absorption capacity is 3%. The free moisture for this sample is:

1. 8%(b) 5%(c) 3%(d) Need more information

9. Which of the following is the most important measure of concrete performance?  

1. Slump test    (b) Compressive strength test(c) Concrete durability test  (d) All  

10. Given a concrete mix with a w/c of 0.4. Adding a water reducer to this mix leads to:

1. higher workability   (b) higher compressive strength(c) better durability (d) All  

Answer 1

1) c) stage III

The initial setting time which takes 30 min and the final setting time which takes 10 hr occurs in stage III

2) Given data : Total moisture content, F=8%

Absorption capacity factor, G=3%

Free moisture content, H=F-G

H =8-3=5%

option(b) 5%

3) option (b) Compressive strength test

Compressive strength is the most important measure of concrete. It is the ability of any material to carry the loads on its surface without any crack or deflection .

4) option(d) All

A water reducer is an admixture, it is made up of some chemical products which reduces the water content in mix upto 5 to 10% thus increse its workability, compressive strength and gives better durability.