Mortar Based on Sludge from Carbonate Dimension Stone Processing Industry - an Experimental and Feasibility Approach

Abstract

The extractive and processing of carbonate dimension stone, such as limestone and marble is particularly important in Portugal. The main extractive centres are in the marble triangle formed by Estremoz, Borba, Vila Viçosa and also the Estremenho Limestone Massif. The large number of quarries and processing units, given the techniques used, both in extraction and processing, and the high-quality criteria required for final ornamental stone products, inevitably lead to the production of stone waste and carbonate sludge. The Geosciences Department at the University of Évora, has a research programme that studies the potential of these wastes as raw materials in other industrial applications. The Calcinata project is the most recent project in this scope which explores this potential. Carbonate sludge has relevant physical and chemical characteristics, which means that they have a strong binding capacity with aggregates, thus allowing their use as a raw material in mortars that can later be used to produce more sustainable composites of stone origin. This research is focused on the study of more sustainable natural stone composite materials that will help to decrease the threatens to natural environment by reducind the amount of carbonate sludges deposited in opend fields and the related geohazards. This work clearly opens a field of investigation regarding the circular use of the natural stone extractive industry residues pointing to innovative solutions for carbonate sludges with obvious positive environmental impacts.