Question:
\(\ldots\ldots\ldots\ldots\ldots\) is used to control the setting time of cement.
\(\ldots\ldots\ldots\ldots\ldots\) is used to control the setting time of cement.
Show Hint
Gypsum is added to cement to prevent flash setting and control the setting time.
Updated On: May 7, 2026
- Lime
- Silica
- Gypsum
- Magnesia
Show Solution
Verified By Collegedunia
The Correct Option is C
Solution and Explanation
Cement contains a phase called tricalcium aluminate:
\[
C_3A.
\]
This phase reacts very quickly with water.
If no controlling agent is added, cement may set too rapidly.
This is called flash setting.
To prevent flash setting and to control setting time, gypsum is added to cement.
Gypsum has the chemical formula:
\[
CaSO_4\cdot 2H_2O.
\]
Gypsum reacts with \(C_3A\) and slows down its hydration.
Because of this, cement remains workable for sufficient time after mixing with water.
Lime, silica, and magnesia are important oxides in cement chemistry, but they are not used specifically to control setting time.
Therefore, the material used to control setting time of cement is:
\[
\text{Gypsum}.
\]
Was this answer helpful?
0
0
Top AP ECET Ceramic Technology Questions
- The Earth's core is primarily composed of
- Which type of rock is formed from cooling Lava or Magma?
- Granite is an example of
- Which of the following is a Metamorphic rock?
- The hardest mineral on the Moh's scale is
View More Questions
Top AP ECET materials science Questions
- The Earth's core is primarily composed of
- Which type of rock is formed from cooling Lava or Magma?
- Granite is an example of
- Which of the following is a Metamorphic rock?
- The hardest mineral on the Moh's scale is
View More Questions
Top AP ECET Questions
- The sum of the four digit even numbers that can be formed with the digits 0,3,5,4 with out repetition is
- Thermal decomposition of $HCOOH$ is a first order reaction and the rate constant at T(K) is $4.606 \times 10^{-3}\, s^{-1}$. The time required to decompose $90\%$ of initial quantity of $HCOOH$ at $T(K)$ in seconds is
- Three rods of same dimensions have thermal conductivities 3 K, 2 K and K. They are arranged as shown below:What will be the temperature T of the junction?
- To which group and period does the element belong if the electronic configuration of an element in its $-2$ oxidation state is $1s^{2} 2s^{2} 2p^{6} 3s^{2} 3p^{6}$ ?
- A ball of mass 0.6 kg attached to a light inextensible string rotates in a vertical circle of radius 0.75 m such that it has a speed of $ 5\text{ }m{{s}^{-1}} $ when the string is horizontal. Tension in string when it h horizontal on other side is $ (g=10m{{s}^{-}}2) $
View More Questions