Strength and durability of self-compacting mortar with waste marble as sand substitution

The growing demand for infrastructure has led to an excessive use of natural resources. On the other hand, marble industry generates large quantities of wastes that could be recycled. In order to preserve natural resources, various methods can be used, including recycling waste into materials that can replace cement or aggregates. This paper investigates the effect of substituting various proportions by weight of natural sand (0 %, 15 %, 30 %, 75 % and 100 %) by marble waste fine particles (MW) on the behavior of a self-compacting mortar (SCM) in the fresh and hardened states. In addition, durability under sulfate attack was assessed. The results show that for an amount of substitution of natural sand by marble wastes not exceeding the proportion of 50 % by weight, a good workability and a flow time are obtained in the fresh state. An increase in compressive and flexural strength is obvious at 90 days of curing for 30 % and 50 % substitution of natural sand by marble waste. A decrease in the porosity at 30 % substitution, is observed. The durability against sulfate attacks was improved as the mortars with 0 % marble presented a decrease in strength, while those with 15 %, 30 % and 50 % marble substitution presented an increase in strength at 180 days of immersion. The specimens were examined by SEM and EDX to detect the possible presence of ettringite.