Mortars with the incorporation of treated ceramic molds shells wastes

About 48 billion tons of aggregates are consumed in the construction, causing a depletion of natural resources. Thus, it is important to apply new solutions that suppress these needs, without environmental impacts and preferably reversing negative impacts associated to other industries, such as foundry industry, a large waste producer commonly deposited in landfills. The main objective of this work was the evaluation of the waste treatment methods effectiveness in the physical and mechanical mortar properties. Fourteen compositions were developed with different contents of ceramic mold shells (0%, 25%, 50%, 75% and 100%) and different types of treatment (series 1 – unwashed ceramic mold shells, series 2 – washed ceramic molds shells and series 3 – washed ceramic mold shells and fibers). The results showed that the treatment of washing residues was quite effective, resulting in an elimination of the expandability and water absorption of the mortars, which led to an increase in the flexural and compression strength, since the microstructure of the mortars was no longer fragile.
This work was supported by FCT/MCTES concerning the Pluriannual funding of R&D Units 2020-2023 for the Centre for Territory, Environment and Construction (CTAC), with reference UIDB/04047/2020 and UIDP/04047/2020.