Influence of cenospheres on properties of magnesium oxychloride cement-based composites

In this study, influence of cenospheres on density, compressive strength, water resistance property and thermal conductivity of magnesium oxychloride cement (MOC)-based composites was systematically investigated, which could provide useful information for the further development of light-weight thermal insulation MOC-based composites. Addition levels of the cenospheres in this study are 0, 5, 15 and 25 %, by weight of magnesia powder. It shows that although compressive strengths of the MOC-based composites are clearly reduced by the incorporation of the cenospheres, they are still maintained at high strength levels above 60 MPa at 28 days. In addition, the use of the cenospheres causes obvious reductions on both composite density and thermal conductivity, demonstrating favorable effects for the further development of light-weight thermal insulation MOC-based composites. However, water resistance property of the MOC-based composites is deteriorated by incorporation of the cenospheres, especially at high addition levels. It suggests that when the cenospheres are used for making light-weight thermal insulation MOC-based composites, their influence on this property should be highly considered.