自流平MKPC浆体组成结构设计及性能试验研究

Composition structure design and performance test study of self-leveling MKPC Paste

通过物理力学性能测试和微观分析,设计了自流平磷酸钾镁水泥(MKPC)浆体的组成结构,并研究了水玻璃、粉煤灰和偏高岭土对其性能的影响。结果表明:在水胶比上限时掺适量水玻璃可提高新拌MKPC浆体的流动度(300 mm),满足浆体自流平要求,且5 h抗压强度达到15.0 MPa以上,硬化过程由体积收缩转为微膨胀变形;用10%粉煤灰等量替代重烧氧化镁粉,新拌MKPC浆体的流动度略减(270 mm),但仍满足浆体自流平要求,且早期和后期强度略有提高,硬化过程微膨胀特性增强;用10%偏高岭土等量替代重烧氧化镁粉,新拌MKPC浆体的流动度略减(250 mm),但仍满足浆体自流平要求,MKPC浆体的早期和后期强度明显提高,硬化时微膨胀特性明显增强。

Through physical and mechanical properties testing and micro-analysis,the composition structure of self-leveling potassium magnesium phosphate cement(MKPC)pastes was designed,and the effect of water glass,fly ash and Metakaolin on its performance was studied.The results are as follows:the appropriate amount of water glass at the upper limit of the water-binder ratio can improve the fluidity of the freshly mixed MKPC paste(300 mm,meet the self-leveling requirements of the paste).When the 5 h compressive strength reaches 15.0 MPa or more,the hardening process changes from volume shrinkage deformation to micro-expansion deformation.If another 10%fly ash is used to replace the dead burned magnesia powders,the fluidity of the freshly mixed MKPC paste is slightly reduced(270 mm,meet the self-leveling requirements of the paste),but its early and late strengths are slightly increased,and the micro-expansion characteristics of the hardening process are enhanced.Or use 10%metakaolin to replace dead burned magnesia powders.The fluidity of the freshly mixed MKPC slurry is slightly reduced(250 mm,meet the self-leveling requirements of the paste),but the early and late strength of the MKPC paste is significantly increased,and the micro-expansion characteristics are significantly enhanced when hardened.