190 mm x 90mmx 80 mm

190 mm x 190 mm x 90 mm

200 mm x 100 mm x 100 mm

200 mm x 200 mm x 100 mm

5 to 10%

20 to 30%

50 to 60%

70 to 80%

cracking and warping of bricks

loss of cohesion

enhancing the impermeability of bricks

none of the above

alumina

silica

iron

magnesia

lime stone and alumina

silica and alkalies

alumina and iron

alkalies and magnesium