*Review* **A Review on the Effect of Mechanical Properties and Durability of Concrete with Construction and Demolition Waste (CDW) and Fly Ash in the Production of New Cement Concrete**

**Sérgio Roberto da Silva and Jairo José de Oliveira Andrade \***

Graduation Program in Materials Engineering and Technology, Pontifical Catholic University of Rio Grande do Sul (PGETEMA/PUCRS), Porto Alegre 90610-900, Brazil; sergio.roberto@acad.pucrs.br **\*** Correspondence: jairo.andrade@pucrs.br

**Abstract:** The search for new alternative materials for employment in the construction industry is necessary for more sustainable development. The construction demolition waste (CDW), as well as by-products generated by initiatives, such as slag, fly ash (FA), palm oil fuel ash (POFA), metakaolin (MK), silica fume (SF), and rice husk ash (RHA), are objects of studies in several segments of the civil construction sector. The addition of these wastes to the materials currently used to produce concrete and mortar can be one of the significant efforts to achieve more sustainable construction. The use of these wastes in the construction sector can bring considerable benefits in terms of costs, energy efficiency, and environmental and ecological benefits. Over the years, many types of research have been developed aiming at the possibility of a practical use of CDW as an aggregate and industrial by-product (FA, POFA, MK, SF, RHA) as pozzolans. Based on recent studies, this paper reviews the current state of knowledge about the production of concrete with partial replacement of natural aggregates by recycled aggregates from CDW and the use of fly ash (FA) as pozzolan in partial replacement with Portland cement. This work discussed the following concrete properties: compressive strength, water absorption, chloride penetration, carbonation, and modulus of elasticity.

**Keywords:** concrete; construction and demolition waste; fly ash; mechanical properties; carbonation
