Effect of Water-Cement Ratio on the Compressive Strength of gravel - crushed over burnt bricks concrete.

The research was conducted to study the effect of water-cement ratio on the compressive strength of gravel-crushed over burnt bricks concrete. Trial mixes were prepared using the crushed over burnt bricks as coarse aggregates only (control), mixture of crushed over burnt bricks and river wash gravel as coarse aggregates and river washed gravel as coarse aggregates only (control) at water – cement ratios of 0.4, 0.5,0.55 and 0.6. Cubes of concrete were prepared and tested to study the compressive strength in relation to the water-cement ratio. The results indicate that the concrete having over burnt bricks as aggregates may be termed as medium light weight concrete having a density between 2000-2200 kg/m3 and that by reducing the water-cement ratio from 0.6 to 0.4 increases the compressive strength from by more than 30%. Use of broken over burnt bricks as coarse aggregate for structural concrete is recommended when natural aggregate is not easily available, high strength of concrete is not required and the bearing capacity of the soil is low. Key words: Aggregates, concrete, compressive strength, water-cement ratio, crushed over burnt brick