水泥的碳酸化工艺研究

Study on carbonation process of cement

通过设计正交实验,测定碳酸化水泥复合胶凝材料与纯水泥的水化产物及观察硬化浆体的微观形貌,研究了水泥的碳酸化工艺条件。结果表明:碳酸化水泥复合胶凝材料3d、28d的抗压强度普遍高于纯水泥,且强度等级由42.5提高至52.5;水量、碳酸化温度对碳酸化复合胶凝材料3d抗压强度有显著影响,且水量的影响作用较大;水泥的碳酸化最佳工艺条件为水量:0.2%、CO2压力:0.2MPa、碳酸化温度:25℃、碳酸化时间:30min;复合胶凝材料3d水化产物中有CaCO3微晶析出,28d水化产物中有较多的碳铝酸钙生成。

Carbonation process of cement was studied by designing orthogonal experiment, determinating the hydration products of carbonation composite cementing material and pure cement and observing the micromorphology of hardened paste. The results showed that the 3 d and 28 d compressive strength of carbonation composite cementing material was higher than that of the pure cement,so its strength grade increased from 42.5 to 52.5; water volume and carbonation temperature both had great impact on the 3d compressive strength of composite cementing material though the impact of water volume was greater; and the optimal carbonation condition of pure cement was 0.2% water content, 0.2 MPa CO2 gas pressure, 25℃ carbonation temperature and 30 min carbonation time; and there was CaCO3 micro-crystal separated out in the 3d hydration products and much calcium carboaluminate in the 28d hydration products of the composite cementing material.