粉煤灰掺量对磷酸钾镁水泥水化动力学的影响  

Effect of Fly Ash Content on Hydration Kinetics of Magnesium Potassium Phosphate Cement

作　　者：赵思勰 晏华[1] 汪宏涛[1] 李云涛[1] 戴丰乐 ZHAO Sixie;YAN Hua;WANG Hongtao;LI Yuntao;DAI Fengle(Department of Chemical and Materials Engineering, Logistical Engineering University, Chongqing 401311, China)

机构地区：[1]后勤工程学院化学与材料工程系,重庆401311

出　　处：《材料研究学报》2017年第11期839-846,共8页Chinese Journal of Materials Research

基　　金：国家自然科学基金(51272283)~~

摘　　要：使用等温微量热仪测定了粉煤灰掺量分别为0、5%、10%、15%、20%和25%的磷酸钾镁水泥((Magnesium potassium phosphate cement,MKPC)在20℃的水化放热速率和放热量。根据Knudsen和Kondo水化动力学公式计算了MKPC水化最终放热量Q_∞、各阶段的水化阻力N和反应速率常数K,研究了粉煤灰掺量对MKPC水化历程的影响机理。结果表明:对于不同粉煤灰掺量的MKPC最终放热量和动力学参数的计算,Knudsen和Kondo水化动力学公式都具有优异的适用性,拟合相关度很高。磷酸钾镁水泥的水化过程可分为6个阶段,水化反应始于第二阶段,水化进行至第四阶段时MKPC由结晶成核直接进入到扩散阶段。随着粉煤灰掺量从0提高到15%,MKPC体系中反应组分MgO和KH_2PO_4的含量减少,水化放热量降低,粉煤灰主要以物理填充作用参与MKPC水化,对磷酸镁水泥水化过程影响较小。当粉煤灰掺量为15%~25%、硼砂相对含量减少时,粉煤灰的火山灰效应显著,水化放热量增大,MKPC各水化阶段的N和K值的变化较大。The rate and quantity of heat release during hydration of magnesium potassium phosphate cement（MKPC） containing 0、5%、10%、15%、20% and 25% fly ash respectively were measured at 20℃ via isothermal calorimetry. The effect of fly ash content on the hydration process of MKPC was investigated in terms of the relevant kinetics parameters, as well as the final heat release Q∞、hydration resistance N and reaction constant K were calculated by the Knudsen and Kondo hydration kinetics formula. The results show that Knudsen and Kondo hydration kinetics formula presented a good applicability for calculation of the final heat release and kinetics parameters of MKPC, with very high relevance fitting.Hydration process of MKPC can be divided into 6 stages, and hydration reaction started from the second stage. At the fourth stage of hydration, MKPC changed from nucleation and crystal growth process to diffusion process directly. The content of reaction components of MgO and KH2PO4 decrease with the increasing fly ash content varied from 0-15%,resulting in decrease of hydration heat of MKPC. Fly ash participanted hydration as physical fitter and showed little influence on the hydration process of of MKPC.When the incorporation amount of fly ash content varied from 15% to 25%, an increase of hydration heat was matched and both content N and K for each hydration stage of MKPC presented huge variation due to the decrease of borax content and the pozzolanic effect of fly ash.

关 键 词：无机非金属材料 水化过程 水化动力学 粉煤灰 磷酸钾镁水泥 火山灰效应 

分 类 号：TU526[建筑科学—建筑技术科学]