Microstructural investigation for micro - nano-silica engineered magnesium oxychloride cement

Eco-friendly and energy-saving cement products can be manufactured by adding silica fume into magnesium oxychloride cement (MOC). A previous piece of research investigated the addition of silica fume to increase the compactness of cement and consequently the strength and resistance to water erosion. Unfortunately, the results were not as expected; although the water resistance improved and the compressive strength decreased, the current research aims to thoroughly investigate the reasons behind those results besides investigating the influence of nano-silica addition on the MOC performance. The results revealed that using nano-silica in replacement for the silica fume was very beneficial to improving the matrix performance. The addition of nano-silica increases the amount of produced M−S−H and forsterite phases concerning silica fume and improves the mechanical properties.