碱激发改性矿粉/砒砂岩复合材料

为了实现砒砂岩的资源化利用,首先,通过碱激发法并掺入适量的矿粉将砒砂岩转变成了力学性能较好的改性矿粉/砒砂岩复合材料;然后,系统地研究了矿粉、碱激发剂掺量和龄期对改性矿粉/砒砂岩复合材料抗压强度和软化系数的影响;最后,利用SEM/EDS、FTIR和XRD分析了改性矿粉/砒砂岩复合材料的水化进程和碳化进程。结果表明:改性矿粉/砒砂岩复合材料的90d抗压强度和软化系数分别达到46.0 MPa和0.94,完全满足工程应用的需求;改性矿粉/砒砂岩复合材料主要的水化产物为C-S-H凝胶和地聚物胶体,且C-S-H凝胶存在比较严重的碳化现象;当矿粉和NaOH的掺量分别为20.0wt%和1.5wt%时,C-S-H凝胶的28d碳化率达30.1%,且碳化率随矿粉及NaOH掺量的增加而减小,但碳化率对强度几乎没有影响。改性矿粉/砒砂岩复合材料拥有良好的力学性能及耐水性。 

Alkali-activated modified steel slag/Pisha sandstone composites

In order to realize the recycling utilization of Pisha sandstone, Pisha sandstone was transformed to modified steel slag/Pisha sandstone composites which had good mechanical properties by alkali-activated method and mixing with suitable amount of steel slag. Then, the effects of dosages of steel slag, alkali-activator and age on compressive strength and softening coefficients of modified steel slag/Pisha sandstone composites were investigated systematacially. Finally, SEM/EDS, FTIR and XRD were used to analyze the hydration process and carbonation process of modified steel slag/Pisha sandstone composites. The results show that the 90 d compressive strength and softening coefficient of modified steel slag/Pisha sandstone composites achieve 46.0 MPa and 0.94 respectively, which fully meet the requirements of engineering application. The main hydration products of modified steel slag/Pisha sandstone composites are C-S-H gel and geopolymer gel, and C-S-H gel has relatively serious carbonation phenomena. When the dosages of steel slag and NaOH are 20.0wt% and 1.5wt% respectively, the 28 d carbonation rate of C-S-H gel reaches 30.1%, and carbonation rate decreases with the dosages of steel slag and NaOH increasing, but carbonation rate has little effect on strength. Modified steel slag/Pisha sandstone composites have good mechanical properties and water resistance.