偏高岭土对天然水硬石灰净浆力学强度和水化反应的影响

Effect of metakaolin on mechanical strength and hydration reaction of natural hydraulic lime grouts

为了研究偏高岭土(MK)对天然水硬性石灰(NHL2)净浆和水化反应的影响,本文制备出了不同偏高岭土掺量的样品(掺入量为0%、10%、20%、30%、40%、50%和60%).采用万能材料试验机、X-射线荧光光谱仪(XRF)、X射线衍射(XRD)、傅里叶变换红外光谱(FT-IR)和扫描电子显微镜(SEM),对养护28天的样品进行了力学强度、化学组成、物相组成及微观结构的分析.结果表明,偏高岭土对天然水硬石灰净浆的力学强度影响显著,当偏高岭土掺量为50%时,养护28天的样品的力学强度最高;偏高岭土中的活性SiO 2与天然水硬性石灰中的Ca(OH)2发生水化反应,促进水化硅酸钙(C-S-H)的生成,抑制了Ca(OH)2的碳化反应,使样品的微观结构呈均匀化和致密化.

In order to study the effect of metakaolin(MK)on natural hydraulic lime(NHL2)grouts and hydration reaction,samples with different metakaolin content were prepared(incorporation of 0%,10%,20%,30%,40%,50%,and 60%),Based on the analysis of universal material testing machine,X-ray fluorescence spectrometer(XRF),X-ray diffraction(XRD),fourier transform infrared spectroscopy(FT-IR)and scanning electron microscopy(SEM),the mechanical strength,chemical compositions,phase composition and microstructure of the 28 days samples were investigated.The result indicated that the metakaolin influence is significant on the mechanical strength of natural hydraulic lime pulp.The 28-day mechanical strength of the sample with 50%metakaolin content is the highest.The hydration happened between the active SiO 2 of metakaolin and the Ca(OH)2 of natural hydraulic lime.The hydration reaction promotes the formation of hydrated calcium silicate(C-S-H)and inhibits the carbonization reaction of Ca(OH)2,and makes the microstructure of the sample uniform and densified.