Consider the following statements: 1) workability of concrete in

Consider the following statements:

1) workability of concrete increases with the increase in the proportion of water content

2) Concrete having small-sized aggregates is more workable than that containing large-sized aggregate

3) For the same quantity of water, rounded aggregates produce a more workable concrete mix as compared to angular and flaky aggregates

4) A concrete mix with no slump shown in the slump cone test indicates its very poor workability

Which of the above statements are correct?

A. 1, 2 and 3 only

B. 1, 2 and 4 only

C. 1, 3 and 4 only

D. 2, 3 and 4 only

Please scroll down to see the correct answer and solution guide.

Factors affecting the workability of concrete	Key points
Water content	It is generally expressed in terms of the water-cement ratio. High water content indicates a high workability of concrete and vice versa.
Rich mix proportion	Rich mix has sufficient cement aggregates, hence it will have a proper lubrication, thus increasing workability.
Size of aggregate	Aggregate with Finer particles have more surface area, hence requires more water to make it workable. Aggregate with coarser particles requires less water to make it workable. Hence for fixed water content large-sized particles are more workable.
Shape of aggregate	The irregular shape of aggregate requires more water to make it workable, due to greater surface area. Rounded shape aggregate requires less water to make it workable, due to less surface area. Hence for fixed water content rounded aggregate has more workability.
Temperature	High temperature reduces the workability of concrete and increases the slump loss.
Use of admixtures	Admixtures such as air-entraining admixtures increase the workability of concrete.