(i) and (ii)

(i)and(iv)

(ii) and (iii)

(iii) and (iv)

gypsum

calcium chloride

calcium carbonate

none of the above

1

2

3

4

to increase the initial setting time of cement paste in concrete

to decrease the initial setting time of cement paste in concrete

to render the concrete more water tight

to improve the workability of concrete mix

ordinary Portland cement

low heat cement

rapid hardening cement

sulphate resisting cement