钛石膏基复合胶凝材料抗碳化性能的研究

RESEARCH ON ANTI-CARBONATION PERFORMANCE OF TITANIUM GYPSUM-BASED COMPOSITE CEMENTITIOUS MATERIAL

为了解决钛石膏综合利用率低、堆放或填埋会污染环境的问题,以钛石膏为原料制备复合胶凝材料。通过改变矿粉、粉煤灰等矿物掺合料与钛石膏掺量间的变化,研究钛石膏基复合胶凝材料碳化前后碳化深度和强度的变化规律,同时通过XRD、SEM对其性能变化的原因进行分析,研究该胶凝材料碳化前后的晶相组成和微观结构的变化。结果表明该胶凝材料碳化性能较P·C32.5复合水泥弱,28d后已完全碳化,且矿粉、粉煤灰矿物掺合料比例越大,碳化深度越浅,碳化后抗压强度越大,其抗碳化性能越好。通过XRD、SEM微观分析发现,钙矾石和CSH凝胶脱钙分解是碳化后抗压强度下降的主要原因。

In order to solve the problem of low comprehensive utilization rate of titanium gypsum and environmental pollution due to stacking or landfilling,titanium gypsum is used as a raw material to prepare composite cementitious materials. By changing the changes between mineral admixtures such as mineral powders and fly ash and the content of titanium gypsum,the changes in the carbonation depth and strength of the titanium gypsum-based composite cementitious materials before and after carbonation are studied. At the same time, the changes in the properties of the titanium gypsum-based composite cementitious materials The reasons are analyzed and the changes in the crystal phase composition and microstructure of the cementitious material before and after carbonation are studied. The results show that the carbonation performance of the cementitious material is weaker than that of 32.5 composite cement. It has been fully carbonized after 28 days. The greater the proportion of slag and fly ash mineral admixtures,the shallower the carbonation depth and the greater the compressive strength after carbonation. The better the carbonation resistance. Through XRD and SEM microscopic analysis,it is found that the decalcification and decomposition of ettringite and CSH gel are the main reasons for the decrease in compressive strength after carbonation.