DefinePK

Abstract

In the last 15 years marble, granite and natural stones wastes were estimated in Egypt as 100 million ton. These wastes were accumulated in wide areas that have a potential for new quarries thus hinder the sustainable development in the quarry areas. This study presents efforts undertaken in Egypt as well as other stone producing countries with an aim to adopt new ideas of re-using these wastes in the production of green concrete. Several attempts concluded the advantage of substituting these wastes to sand and cement in the concrete mix. Wastes improved the physical and mechanical properties of concrete due to its high fineness which provided good cohesiveness of concrete. Many tests revealed that 10% substitution of sand by the marble waste in the presence of a super-plasticizing admixture provided maximum compressive strength at the same workability level, comparable to that of the reference mixture after 28 days of curing. Regarding higher contents of stone slurry (substitution of more than 20% of sand), the decrease of compressive strength values was significant. Concrete mixes containing 30% red granite dust showed comparable compressive strength using natural or recycled aggregates, good workability, and excellent reddish colored surface finish. In general, the use of marble dust as sand replacement has more significant effect on the mechanical properties of concrete compared with using it as cement replacement.