碳化养护对钢渣-熟石灰固碳砖耐久性的影响

Effect of Carbonation Curing on Durability of Carbon Fixing Steel Slag-Slaked Lime Brick

摘要:

研究了碳化养护工序对钢渣-熟石灰固碳砖抗冻融性能、抗硫酸盐侵蚀性能和抗盐结晶压性能等耐久性的影响，并用X射线衍射分析、热分析、孔结构分析和扫描电子显微分析对硬化浆体的微观结构进行了表征，揭示了其耐久性的改善机理.结果表明：钢渣-熟石灰固碳砖具有优良的耐久性；碳化养护过程中，钢渣-熟石灰固碳砖中化学稳定性差的Ca（OH）₂转变为稳定性高的CaCO₃，硬化浆体的孔结构得以细化，因而钢渣-熟石灰固碳砖的耐久性得到显著改善；钢渣-熟石灰固碳砖的综合CO₂减排效益为179.4 kg/t， 钢渣利用率为238.0 kg/t，环保效果显著.

Abstract:

The effect of carbonation curing process on the durability of the carbon fixing steel slag-slaked lime brick， such as freezing-thawing resistance， sulfate resistance and salt crystallization resistance， were investigated. The microstructure of the hardened paste was characterized by X-ray diffraction analysis， thermal analysis， pore structure analysis and scanning electron microscopy analysis， and the mechanism of durability improvement was revealed. The results show that the durability of carbon fixing steel slag-slaked lime brick is excellent. During the carbonation process， Ca（OH）₂ with poor chemical stability in the carbon fixing steel slag-slaked lime brick is transformed into CaCO₃ with high stability， and the pore structure of the hardened paste is refined， thus the durability of the carbon fixing steel slag-slaked lime brick is significantly improved. The comprehensive CO₂ emission reduction efficiency of the carbon fixing steel slag-slaked lime brick is 179.4 kg/t， the utilization ratio of steel slag is 238.0 kg/t， and the environmental protection effect is remarkable.