三乙醇胺对水泥-粉煤灰体系水化进程与强度的影响机制

Effect of Triethanolamine on Hydration Process and Strength of Cement-Fly Ash System

为掌握三乙醇胺(TEA)水泥-粉煤灰体系水化与强度的影响规律及其机理,促进粉煤灰的有效利用,采用等温量热法测试分析了不同温度条件下TEA对水泥-粉煤灰体系水化放热行为和体系活化能的变化,通过热重和X射线衍射分析了掺TEA水泥-粉煤灰体系的物相组成及其变化,研究了TEA对水泥-粉煤灰体系水化进程和强度的影响规律。结果表明,TEA和温度均水泥-粉煤灰体系水化放热和强度发展存在较大影响。TEA提高了粉煤灰在72 h内的反应热,促进了水泥-粉煤灰体系早期的水化放热,并且在高温下更加明显,水泥-粉煤灰体系活化能随着TEA掺量增加而降低,TEA对水泥熟料矿物铝酸三钙(C3A)、硅酸三钙(C3S)和硅酸二钙(C2S)在不同龄期内的水化进程影响不同,TEA在早期对C3A熟料的水化具有明显的促进作用,而对C3S和C2S的水化则有延缓作用。

In order to obtain the influence of triethanolamine(TEA)on hydration and strength of cement-fly ash system and its mechanism,and to promote the effective utilization of fly ash,the changes of hydration exothermic behavior and activation energy of cement-fly ash system by TEA at different temperatures were measured and analyzed by means of isotherm calorimetric method.The phase composition and change of cement-fly ash system mixed with TEA were investigated by thermogravimetry and X-ray diffraction.The effect of TEA on hydration process and strength of cement-fly ash system was studied.The results show that TEA and curing temperature has a great influence on the hydration exothermic and strength development of cement-fly ash system.TEA increases the reaction heat of fly ash within 72 h promotes the early hydration heat release of cement-fly ash system,and becomes more obvious at high temperature.The activation energy of cement-fly ash system decreases with the increase of TEA content.TEA has different effects on the hydration process of cement clinker minerals C3A,C3S and C2S at different ages.TEA can obviously promote the hydration of C3A clinker in the early stage,but delay the hydration of C3S and C2S.