掺珊瑚砂粉砂浆抗硫酸镁侵蚀性能研究OA北大核心CSTPCD

This paper investigated the magnesium sulfate resistance of mortar incorporating coral sand powder(CSP)combined with supplementary cementitious materials(SCMs).With erosion in magnesium sulfate(MgSO4)solution at 5 and 20 ℃ for 365 d,the magnesium sulfate attack resistance of mortar was analyzed through appearance,length change,compressive strength,X-ray diffraction pattern and Fourier transform infrared spectroscopy.It is found that the mortar with CSP deteriorates seriously when it is eroded to 365 d in magnesium sulfate solution at 5 ℃.Sulfate resistantance Portland cement(SRPC)with 20％(mass fraction)CSP exhibits better magnesium sulfate attack resistance than ordinary Portland cement(OPC)with 20％(mass fraction)CSP.Fly ash and slag can effectively improve the magnesium sulfate attack resistance of mortar with CSP at 5 ℃,while silica fume reduces the magnesium sulfate attack resistance at 20 ℃.At 5 ℃,the mortar with CSP mainly undergos magnesium and thaumasite sulfate corrosion accompanied by a small amount of gypsum generation,while at 20 ℃,magnesium and gypsum-type sulfate corrosion mainly occurs.