Microstructure and properties of recycled concretes using ceramic sanitary ware industry waste as coarse aggregate

Due to its physical, chemical and mechanical properties, the waste inevitably generated by the ceramic sanitary ware industry can be used in the production of concrete. This article reports the possibility of substituting 15%, 20% and 25% of natural coarse aggregate with recycled ceramic coarse aggregate, and presents an analysis of the resultant effects on the morphology and microstructure of recycled concretes, and consequently, on the mechanical behaviour of these ecoefficient concretes. The results demonstrate that ceramic waste does not interfere in either the hydration process or in the morphology of the hydrated products. The microstructure present in the interfacial transition zone (ITZ) of the recycled aggregate–paste is more compact and stable than that of the natural aggregate–paste. As regards mechanical behaviour, it was observed that as the percentage of substitution rose, the compressive strength of these concretes improved.

► The ceramic waste analysed from the sanitary ware industry.
► This waste is used as a coarse aggregate in the manufacture of concretes.
► The mechanical behaviour of these concretes is better than convectional concretes.
► ITZ of the new aggregate/paste is more compact and stable than natural aggregate.
► The new aggregate does not interfere in the microstructure of recycled concretes.