Al2O3掺杂对γ-C2S碳化性能的影响

本文研究了Al₂O₃掺杂对γ-C₂S熟料粒径、微观结构和力学性能的影响。试验结果表明:Al₂O₃掺杂不会改变γ-C₂S的晶型,但显著改变了其形貌;纯相γ-C₂S颗粒表面褶皱较多,颗粒尺寸较大,掺杂Al₂O₃后γ-C₂S颗粒表面褶皱消失而变得光滑;γ-C₂S碳化体的抗压强度与碳化程度随着Al₂O₃掺量的提高逐渐增加。通过碳化反应温升并结合碳酸钙衍射峰的半峰宽和X射线衍射仪(XRD)定量分析表明,Al₂O₃掺杂延缓了碳化放热,有利于碳化反应的持久进行,同时促进了碳酸钙晶粒的生长和数量的增加,从而使碳化程度更高,基体结构更加密实,因而抗压强度更高。

Effect of Al2O3 Doping on Carbonation Performance of γ-C2S

The effect of Al₂O₃ doping on the particle size, microstructure and mechanical properties of calcined γ-C₂S clinker was investigated. Results indicate that Al₂O₃ doping has no influence on the crystal form of γ-C₂S, but significantly changes its morphology. The undoped γ-C₂S grains exhibit wrinkly surface morphology and the particle size is larger. After Al₂O₃ doping, the grain surface becomes smooth. The compressive strength and the degree of carbonation of γ-C₂S carbonated for 24 h gradually increase with the increasing content of Al₂O₃. Based on the carbonation temperature rise, full width at half maximum of the diffraction peaks of calcium carbonate and the quantitative XRD analysis, Al₂O₃ doping retards the heat release of carbonation, which is beneficial for a more sustained carbonation reaction. Al₂O₃ doping also promotes the growth and the number of calcium carbonate crystals, which increases the degree of carbonation, densifies the carbonated matrix and increases the compressive strength.