Question

It results in the failure of concrete made from the cement if the amount of alkali oxides in it exceeds _________

(a) 1%

(b) 5%

(c) 12%

(d) 17%

I have been asked this question by my college professor while I was bunking the class.

Asked question is from Plain and Reinforced topic in division Miscellaneous Materials, Plain and Reinforced Cement Concrete of Construction & Building Materials

Answer 1

Correct option is (a) 1%

The explanation is: The presence of alkali oxides and magnesium oxide badly affects the quality of the cement. It results in the failure of concrete made from the cement if the amount of alkali oxides in it exceeds 1%.