普通硅酸盐-硫铝酸盐复合胶凝体系水化性能和机理研究

Hydration Properties and Mechanism of Portland Cement-Sulphoaluminate Cement Compound System

对普通硅酸盐(P·O)-硫铝酸盐(R·SAC)复合胶凝体系的凝结时间、胶砂强度进行了分析,利用等温量热仪、综合热分析仪(TG-DSC)、扫描电镜(SEM)、X射线衍射仪(XRD)等从水化速率及水化产物微观形貌等方面分析了复合胶凝体系的水化机理。结果表明:当R·SAC掺量约为10%时,复合胶凝体系的凝结时间相比P·O明显缩短,早期强度提高幅度较大,同时也能获得较大幅度的后期强度增长,力学性能较纯组分水泥性能优越。复合胶凝体系的早期水化速率和放热量高于单组分水泥。随着R·SAC的掺入,复合胶凝体系的水化产物中钙矾石(AFt)增多,Ca(OH)2晶体减少,且AFt的生成量越多,越有利于早期强度的发展,当R·SAC掺量超过30%时,Ca(OH)2消失。

The setting time and the mortar strength of the ordinary silicate(P·O)-sulphoaluminate(R·SAC)composite gelling system were analyzed.The hydration mechanism of the composite gelling system was analyzed by means of isothermal calorimeter and comprehensive thermal analysis(TG-DSC),scanning electron microscopy(SEM)and X-ray diffraction(XRD).The results show that the incorporation of about 10%R·SAC in P·O,setting time of composite cement was significantly shorter than P·O,the early strength was greatly increased,and the later strength of composite cement was also increased,the mechanical properties are superior to those of pure component cement.The early hydration rate and heat release of composite cement are higher than those of single component cement;The main hydration products of composite cement are calcium alunite(AFt),Ca(OH)2 crystals,C-S-H gel,etc.,and the more the amount of AFt is generated,the more favorable the development of early strength.