Question

Which of the following pairs are correct related to rapid hardening cement?
(1) Fineness: 10%
(2) Final setting time : 10 hours
(3) Initial setting time : 30 minutes
The correct answer is-

• A. 1, 2 and 3
• B. 1 and 2
• C. 2 and 3
• D. 1 and 3

Answer 1

The correct option is C 2 and 3

Ans : (c) Fineness is the measure of the size of the cement particles in terms of specific surface (i.e. surface area per unit mass). The sample is placed on a 90 $\mu$ sieve and continuously sieved for 15 minutes.

The residue should not exceed the limits specified below

Type of cement % residue by weight
1. Ordinary Portland cement 10%
2. Rapid hardening cement 5%
3. Portland Pozzolana cement 5%

$\Rightarrow$ Final setting time :10 hours
$\Rightarrow$Initial setting time : 30 minutes