Development of alternative porous magnesium potassium phosphate cements as thermal insulating materials

Abstract

Magnesium potassium phosphate cement (MKPC), a type of chemically bonded phosphate ceramic (CBPC), presents a promising alternative to ordinary Portland cement (OPC). This study focuses on developing sustainable MKPC (sust-MKPC) as a thermally passive material for building applications. A low-grade magnesium oxide (LG-MgO) industrial by-product was utilized to formulate sust-MKPC, with hydrogen peroxide employed as an air-entraining agent (AEA) to induce high porosity and enhance thermal insulation while supporting sustainability goals by reducing energy consumption in climate control systems. Seven formulations incorporating varying hydrogen peroxide contents (0, 1, 2, 3, 5, 7.5, and 10 wt.%) were prepared to evaluate the impact of AEA on the thermal and physicomechanical properties. Comprehensive characterization, including porosity and thermal conductivity measurements, revealed that increasing the AEA content significantly improved thermal inertia and lowered thermal conductivity due to porosity. However, this enhancement was accompanied by a marked reduction in mechanical strength and density, highlighting the trade-off between thermal performance and structural integrity in porous sust-MKPC formulations.

The authors of the Universitat de Barcelona would like to thank the Catalan Government for the quality accreditation given to their research group DIOPMA (2021 SGR 00708). DIOPMA is a certified agent of TECNIO in the category of technology developers from the Government of Catalonia. The authors acknowledge the support of CYTED Network ECoEICo-Circular Economy as a Strategy for a More Sustainable Construction Industry and the COST Action CircularBImplementation of a Circular Economy in the Built Environment. This research was supported by the Spanish Government with the Grant PID2021-125810OBC21 funded by MCIN/AEI/10.13039/501100011033 and by “ERDF A way of making Europe”, and with the grant CNS2022-135800 funded by MICIU/AEI/10.13039/501100011033 and by the “European Union NextGenerationEU/PRTR”. The authors would like to thank the Catalan Government for the quality accreditation and funding given to their research group DIOPMA (2021 SGR 00708). This work is also partially supported by Magnesitas Navarras, S.A. (FBG312160).

Peer Reviewed

Postprint (published version)