Question

At normal temperatures addition of sugar _____________ per cent have little effect on the rate of hydration.

(a) .5-1

(b) 1-2

(c) .05-.1

(d) .1-.2

I got this question in semester exam.

The origin of the question is Accelerators and Retarders topic in portion Admixtures and Construction Chemicals of Concrete Technology

Answer 1

Correct answer is (c) .05-.1

Easy explanation: At normal temperatures addition of sugar .05-.1% have little effect on the rate of hydration, but if the quantity is increased to 0.2 percent, hydration can be retarded to such an extent that final set may not take place for 72 hrs.