Application of construction and demolition waste in mortars and after heat treatment: A review

Construction and demolition waste (CDW) usually accumulates during various stages of the construction, renovation and demolition process. It might constitute a major environmental problem due to its high volume, poor management and inadequate disposal. An efficient alternative is waste recycling, CDW stands out with great potential for recycling and sustainable development. This article reviews previous studies that applied construction and demolition waste in mortars as a partial substitute for cement and sand and after heat treatment. For that, a survey was carried out in the following databases: Science Direct, Scopus and Web of Science. It is concluded that the CDW type and the degree of replacement used influence the mechanical resistance of the mortars. In particular, fine residual mortar powders contribute to the CDW strength due to the filling effect. In addition to the filling effect, heat-treated CDWs contribute to mechanical strength owing to the rehydration of the products, through the new C-S-H gel formed when exposed to water again. Considering the variety of CDW and its influence on mortar properties, studies are still needed to provide a better understanding for possible applications, such as its useful life, the durability of mortars with partial replacements by thermoactivated CDW, which are the gaps found.