Physico-mechanical properties of solid cement bricks containing recycled aggregates

Recycling and reuse of solid wastes as alternative building materials present interesting possibilities for economy on waste disposal sites and conservation of natural resources. This paper investigates the physical and mechanical properties of solid cement bricks manufactured with crushed clay bricks as recycled aggregates. Four series of mixtures with cement content 100, 150, 200 and 300 kg/m^3 were prepared. In each series, either natural fine aggregate, coarse aggregate or both were replaced with crushed brick aggregates (CBA) at 0%, 50% and 100% by volume. Compressive strength, unit weight and water absorption were determined and compared with the relevant national and international standards for load bearing and non-load bearing units, respectively. The experimental results showed that as the replacement level of natural aggregates increased, the unit weight and compressive strength of solid cement bricks decreased and the water absorption increased regardless of cement content. Furthermore, it is possible to manufacture different grades of solid cement bricks with CBA to be used as load bearing and non-load bearing units depending on the size of the crushed bricks and the replacement percentage of natural aggregates.