EVA对硫铝酸盐水泥净浆微观结构和力学性能的影响

Effect of EVA on Microstructure and Mechanical Properties of Calcium Sulfoaluminate Cement Paste

研究了乙烯-醋酸乙烯酯(EVA)对硫铝酸盐水泥(CSA)净浆抗压强度、凝结时间、干燥收缩、质量损失及浆体内部温度的影响规律,并通过XRD、FTIR、SEM及EDS等测试手段对6 h、28 d龄期时的水化产物及微观结构进行分析。结果表明:掺入EVA后CSA净浆的凝结时间显著缩短,6 h的抗压强度升高,而1 d、3 d、28 d的抗压强度降低;CSA净浆的干燥收缩和质量损失率随着EVA掺量的增加逐渐减小;EVA的掺入提高了CSA净浆内部温度曲线的峰值,加快了峰值出现的时间。微观分析表明:EVA对CSA净浆6 h的水化具有促进作用,使其生成了更多的钙矾石,而对其28 d的水化具有抑制作用,水化产物有所减少。

The effect of ethylene-vingyl acetate(EVA)on compressive strength,setting time,drying shrinkage,mass loss and internal temperature of calcium sulfoaluminate cement(CSA)paste was studied,and the hydration products and microstructure at the age of 6 h and 28 d were analyzed by X-ray diffraction(XRD),Fourier transform infrared spectroscopy(FTIR),scanning electron microscope(SEM)and energy dispersive spectroscopy(EDS).The results show that the setting time of CSA paste decreases significantly with the addition of EVA,and the compressive strength increases at 6 h,but decreases at 1 d,3 d,and 28 d.The drying shrinkage and mass loss ratio of CSA paste gradually decrease with the increases of EVA.The addition of EVA improves the peak value of the internal temperature curve of CSA paste,and accelerates the appearance time of the peak value.Microscopic analysis shows that EVA could promote the hydration of CSA paste at 6 h,resulting in the formation of more ettringite,while it has inhibitory effect on the hydration of CSA paste at 28 d,and the hydration products reduce.