Author : Mohamed R. Afify and Noha M. Soliman

Recently, it has been taken into consideration the use of the recycle aggregate from old concrete, clay brick and waste materials, the recycle concrete is considered as one of the most important materials in the special concrete groups. It has extensive applications in the architect and insolation work. Many research studied the effect of this recycle aggregates on the properties of concrete. Chemical admixtures and cement content play an important role in the production of recycle concrete. This research is to establish the improvement properties of recycle concrete using clay brick as a coarse aggregate. Plan concrete specimens cast with concrete containing such recycle aggregate were cast and tested in the research. Using crushed clay brick was manufactured by local factories as an aggregate with replacement ratio as 100 % by volume of coarse aggregate. The main variable taken into consideration were the aggregate type, cement and water content as well as the chemical and mineralogical admixtures content. The mechanical properties as the compressive strength, the tensile strength and flexural strength of fifteen concrete mixes were measured in the experimental work at 7, 28, 90 and 180 days when they curing in salt solution and in the water. The results show that the hardened properties of recycled concrete improved by reducing the water/ cement, increasing admixture/ cement and using silica fume. Curing in salts decreased the compressive strength of recycled concrete compared to curing in water.

Keywords: recycled concrete, clay brick, recycled aggregate, aggregate, curing conditions, durability, Polymer Matrix Composites, Injection Moulding, Flexural Strength, Hardness.

Article published in International Journal of Current  Engineering  and Technology, Vol.4,No.1 (Feb- 2014)