Recycled aggregate concrete produced with red granite dust as a partial cement replacement

Sustainable development involves reducing natural resource consumption by appropriate recycling. To reduce the amount of waste going to landfill, red granite dust arising from the rock-crushing process was assessed for suitability as a replacement for up to 30% by mass of the cement content of structural grade concretes made with recycled coarse aggregates. While the impact on worldwide cement demand will be minimal, the contribution to waste reduction may be valuable. Laboratory trials showed that this red granite dust rendered it suitable in terms of workability, stiffness and strength compared to normal aggregate and Portland cement concretes. The potential for thereby overcoming the problem of low early strength in some pulverised fuel ash concretes was demonstrated.

► Use of a new recycled material (red granite dust) as a partial cement replacement in concrete mixes.
► Selection of optimum recycled material content and the evaluation of fresh and hardened properties.
► RGD addition beyond 30% caused a strength decrease: mechanical properties remained acceptable up to 50% RGD-for-cement replacement.