Synergistic Effect of CDWs as Eco-Pozzolans: Ternary Cements

Sustainable development and circular economy policies currently prioritize the recovery of industrial waste and rubble as secondary raw materials. CDWs fine fractions of concrete nature are focusing special attention due to their accumulation, subjected to weather conditions and without any industrial application at present. These wastes have little pozzolanic activity which is why it is necessary to combine it with other active additions for the ternary cements manufacture. In the present, a laminar glass waste from the deconstruction has been selected in order to obtain the binary mix. A binary mixture of pozzolan recycled concrete/glass with a 1:2 ratio has been prepared to evaluate the synergy of both wastes in the pozzolanic reaction, and its possible commercialization for future ternary cements that are more sustainable. The characterization of materials and reaction kinetics mainly in the ternary pastes have been characterized by XRF, ICP/MS, NMR, FTIR, XRD-Rietveld and SEM/EDX, detecting calcite, quartz, mica, feldspar and clay minerals and as hydrated phases ettringite, aluminates and C-S-H gels. According to these results, it can be highlighted that from the scientific point of view, this mixture of pozzolans from CDWs are viable for use as ecoefficient pozzolans for the more sustainable ternary cements.