Question

Portland cement contains '$\text{X}$' to enhance the setting time. What is '$\text{X}$'?

• A. ${\text{CaSO}}_4$
• B. ${\text{CaSO}}_4\cdot \frac{1}{2}{\text{H}}_2\text{O}$
• C. ${\text{CaSO}}_4\cdot 2{\text{H}}_2\text{O}$
• D. ${\text{CaCO}}_3$

Answer 1

The correct option is C ${\text{CaSO}}_4\cdot 2{\text{H}}_2\text{O}$

Portland cement contains gypsum, $({\text{CaSO}}_4\cdot 2{\text{H}}_2\text{O})$, which is used to enhance the setting time of cement to avoid cracks.