关键词: 轻烧氧化镁;活性含量;碱式硫酸镁水泥;强度;水化产物

Abstract: In order to study the influence of reactive magnesium oxide(MgO)content on strength and hydration products of basic magnesium sulfate cement(BMSC),the flexural and compressive strength of BMSC mixed with different content of reactive MgO were tested.And hydration products were analyzed by X-ray diffraction method.The results show that the compressive strength of specimens with 60％reactive MgO is highest than the specimens with reactive MgO content of 43.2％and 70％at curing age of 28 d when the modifier addition amount of 1％by weight of reactive MgO.And large amounts of 5·1·7 phase whiskers were formed in hydration products of specimens with 60％reactive MgO.Higher content of reactive MgO of 70％is more liable to the formation of Mg(OH)2 in hydration reaction for less content of modifier additive.So the strength is lower than the specimens with 60％reactive MgO by 60％.The hydration products in the paste mixed with lower content of reactive MgO of 43.2％are less 5·1·7 phase,more Mg(OH)2,residual MgCO3 and MgO.Increasing the modifier addition amount to 2％by weight of reactive MgO,the compressive strength of the phase mixed with reactive MgO content of 70％was improved greatly at each curing age.

Key words: light-burnt magnesium oxide;reactive oxide content;basic magnesium sulfate cement;strength;hydration product