Question

In cement, following compounds can be used as accelerators except

• A. $CaC{l}_2$
• B. $CaS{O}_4$
• C. $NaCl$
• D. $N{a}_{2}S{O}_4$

Answer 1

The correct option is B $CaS{O}_4$

Retarder is used to slow down the setting rate of concrete which is used to counteract the accelerating effect of hot weather on concrete setting.
$\text{Ex.}CaS{O}_4$
Accelerators make concrete set faster rapidly after mixing with concrete. At high temperature after causing an increased rate of hardening which makes placing and finishing difficult.
$\text{Ex.}CaC{l}_2$