Properties of foam concrete prepared from magnesium oxychloride cement

Abstract

To broaden the application of magnesium oxychloride cement (MOC) in thermal insulation materials, lightly burned magnesia powder and magnesium chloride hexahydrate were used as the main raw materials of cement and a chemical foaming method was used to prepare a magnesium oxychloride cement foam concrete (MOCFC) with fast hardness and early strength. By changing the molar ratio (M) of the MOCFC and adding different dosages of hydrogen peroxide (H2O2), fly ash (FA), potassium dihydrogen phosphate (KDP) and other admixtures, while measuring and observing the compressive strength and flexural strength at 3, 7, and 28 days, the thermal conductivity, dry apparent density, volume water absorption, softening coefficient, and other parameters, combined with its hydration phase composition and microscopic appearance, the effect of the molar ratio and the admixtures on the properties of MOCFC were studied. The results show that with an increase in the molar ratio and the dosage of H2O2, FA and KDP, the internal pore structure of the slurry changes significantly, which affects its mechanical properties, water resistance, and thermal insulation performance.