Question

Percentage of silica in good brick earth should be about _________

(a) 10-15%

(b) 20-35%

(c) 50-60%

(d) 80-90%

The question was posed to me in an interview for internship.

This key question is from Bricks topic in portion Glass, Lime, Clay Products & Bricks of Construction & Building Materials

Answer 1

The correct option is (c) 50-60%

To explain I would say: Percentage of silica in good brick earth should be about 50-60%. Silica exists in clay either in the combined state or in the free state. Its presence prevents shrinking and cracking of raw bricks.