1.宁夏大学土木与水利工程学院;2.辽宁科技大学材料与冶金学院
国家自然科学基金资助项目
1.School of Civil &2.Water Conservancy Engineering, Ningxia University;3.College of Materials and Metallurgy, University of Science and Technology Liaoning
National Natural Science Foundation of China
以CO2气氛作为养护条件，研究了不同掺量的花岗岩石粉（GP）对硫氧镁（MOS）水泥性能的影响，结合X射线衍射仪（XRD）、同步综合热分析仪（TG-DSC）、扫描电镜（SEM）、压汞仪（MIP）对MOS水泥水化产物及微观结构做了分析。结果表明：碳化28 d后的掺加40% GP的MOS水泥强度保留系数提高至1.12；碳化28 d后浸水120 d强度保留系数为0.94，较空白样提高了123.8%；MOS水泥碳化过程中基体内Mg(OH)2转化为MgCO3·zH2O晶体，降低了基体膨胀；GP改善了MOS水泥孔结构，提高了密实度，降低了CO2吸收率，减弱了CO2的侵蚀作用；GP和MgCO3·zH2O改善了MOS水泥抗碳化性能和耐水性能。
The properties of magnesium oxysulfate (MOS) cement with different granite powder (GP) contents with CO2 curing were studied. The hydration products and microstructure of MOS cement were conducted by X-ray diffraction (XRD), simultaneous comprehensive thermal analyzer (TG-DSC), scanning electron microscope (SEM) and mercury porosimeter (MIP). The results shows that: the strength retention coefficient of MOS cement containing 40% GP reaches 1.12 with standard curing 28 d and then in CO2 for 28 d; when MOS cement with CO2 curing 28 d and then immersion in water for 120 d, the strength retention coefficient reaches 0.94, which is 123.8% higher than blank samples; MgCO3·zH2O crystals generated after MOS cement with CO2 curing, which has a positive effect on mechanical properties and water resistance of that via reducing matrix expansion caused by MgO hydrated to Mg(OH)2; GP increases the matrix dense, reduces CO2 capture rate and decreases CO2 erosion of MOS cement by optimizing the pore structure; GP and MgCO3·zH2O improves the carbonation resistance and water resistance of MOS cement.
