Eco-efficient alkali-activated cement based on red clay brick wastes suitable for the manufacturing of building materials

Abstract

The objective of this study was to obtain hybrid-type binders at room temperature (25 °C) from the alkaline activation of a red clay brick waste and the addition of a reduced amount (≤30%) of Portland cement. Different types of activators were used, including solids (Na2SO4, Na2CO3, NaOH) and liquids (Na2SiO3xH2O). The results highlight the possibility of obtaining an eco-efficient, hybrid cement with compressive strengths of up to 102 MPa at 28 days and reductions of up to 73% in the global warming potential (expressed in kg·CO2·eq/MPa) associated with a Portland cement paste. Based on the optimum hybrid cement, a mortar was developed and used as a base material for the production of block and paver construction elements that comply with construction industry standards.