温度对高掺量矿渣水泥水化放热性能的影响

Effect of Temperature on Sulfate Resistance of Cement Paste with High Content of Blast Furnace Slag

采用TA Air等温微量热技术研究了不同温度对掺减水剂的矿渣-水泥浆体(Slag-Cement Paste,SCP)水化放热性能的影响规律,运用Krstulovic-Dabic模型,对不同反应温度下不同减水剂掺量的矿渣-水泥浆体水化反应动力学控制机制(NG-I-D)进行了表征,得到反应速率常数K、反应级数n等动力学参数以及各反应阶段的反应速率与反应程度之间的关系。结果表明:当养护温度为20℃时,随着矿渣掺量的增加,I(相边界反应)过程逐渐加强,掺50%矿渣的水泥浆体20℃时具有明显的NG-I-D反应过程,即反应初期为结晶成核与晶体生长(NG)机制,中后期转为相边界反应(I)和扩散(D)机制;35℃和50℃时主要由NG-D过程控制。

The influence of different temperatures on hydration exothermic performance of slag-cement paste was investigated using isothermal calorimetry. Based on the KrstulovimDabic model, hydration kinetics control mechanism （NG--I--D） of slag-cement paste with different reaction temperatures and different dosages of superplasticizer were characterized. The relationship between kinetic factors such as reaction rate constant K, reaction exponent n and reaction rate, the extent of reaction in different reaction stages were determined. The results show that, when the curing temperature is 20℃, with the slag content increasing, I process gradually strengthened, cement paste mixed with 50% slag is NG--I--D reaction process at 20℃, nucleation and crystal growth （NG）in the initial stage of the reaction, interactions at phase boundaries （I） and diffusion （D） in the late. NG-D reaction process mainly dominates at 35℃ and 50 ℃.