Influence of metasteatite on strength and porosity of magnesium oxychloride cement: An experimental and image processing approach

Abstract

In this study work, the impact of metasteatite on the mechanical and microstructural properties of magnesium oxychloride cement (MOC) is investigated. The MOC paste cubes with metasteatite concentrations ranging from 0% to 25% with 5% interval was tested to compressive strength at curing ages of 3, 14, and 28 days. The microstructural properties of MOC matrix with varying content of metasteatite replacement were analyzed utilizing scanning electron microscopy (SEM) images through image processing technique. Further, it is quantified with porosity values and pore size distributions. TGA was performed to elucidate the mechanism underlying the improved water resistance of the novel MOC. The results showed that incorporating metasteatite into the MOC matrix significantly reduced the compressive strength at all curing ages compared with the control sample. Each mixture exhibited a notable pattern of prolonged hydration time, with a substantial increase in strength at 14 and 28 days containing 10–25wt.% of metasteatite. The potential for strength retention in MOC specimens containing metasteatite of 10% was significantly enhanced compared with that of the control specimen. The addition of metasteatite enhanced the porosity and pore structure, and the best results were achieved with a replacement rate of 10% in the MOC matrix.