Building Materials - Study Mode
[#146] For preparing porcelains, the clay should be
Correct Answer
(D) All the above
[#147] Bessemer process is used for the manufacture of
Correct Answer
(D) Steel
[#148] For testing compressive and tensile strength of cement, the cement mortar is made by mixing cement and standard sand in the proportions of
Correct Answer
(B) 1 : 3
[#149] Bullet proof glass is made of thick glass sheet sandwiched by a layer of
Correct Answer
(C) High test plastic
[#150] Good quality cement contains higher percentage of
Correct Answer
(A) Tri-calcium silicate
Explanation
Solution: Option A: Tri-calcium silicate (C3S) - This is the most important compound in cement. It's responsible for the early strength development (within the first week). A higher percentage of C3S means faster setting and hardening , which is generally desired in good quality cement. Option B: Di-calcium silicate (C2S) - This contributes to strength gain over a longer period (after the first week). While important, it's not the primary factor determining early strength and overall cement quality as much as C3S. Option C: Tri-calcium aluminate (C3A) - This contributes to very early hydration and heat generation. A high percentage of C3A can lead to flash set and reduced durability, especially in sulfate-rich environments. Good quality cement generally has a controlled amount of C3A , not a higher percentage. Option D: Tetra calcium alumino ferrite (C4AF) - This reduces the clinkering temperature during cement production. It has minimal contribution to the strength of cement. Therefore, the correct answer is: Option A: Tri-calcium silicate , as it contributes to faster setting and hardening and higher early strength of the cement.