硅灰石粉对水泥基砂浆力学性能影响的研究

摘要

Based on the activity index experiment of wollastonite paste,the paper makes a systematic studyon the mechanical properties of wollastonite-cement mortar such as flexural strength,compressive strength,shock resistance and elasticity modulus. According to the re-sults,the compressive activity index of wollastonite powder is 67%.The XRD analysis indicates that in the later hydration process of mor-tar,wollastonite powder takes part in the hydration reaction,whose characteristic peak strength drops somewhat;compared with the perfor-mance of reference mortar,under the premise of same compressive strength,wollastonite powder can enhance the flexural strength,shock resistance and the elasticity modulus of the mortar while reduce reduce the load deformation.The SEM analysis indicates that wollastonite powder generates hydration products at the surface and forms compact interlocked mass with cement mortar.The structure has a distinctive effect of micro-fiber reinforcement on the mortar;besides,when the amount of admixture reaches or exceeds 25%,wollastonite powder will form 3D network framework in the paste.%基于硅灰石胶砂活性指数试验的基础上，对硅灰石-水泥砂浆抗折强度、抗压强度、抗冲击性能和弹性模量等力学性能进行了系统研究。结果表明，硅灰石胶砂抗压活性指数为67%。通过XRD分析表明，在胶砂后期水化过程中，硅灰石粉参与水化反应，特征峰强度有所降低；与基准砂浆性能对比，在抗压强度相同前提下，硅灰石粉能提高砂浆抗折强度、抗冲击性能和弹性模量，并降低试件荷载变形。通过SEM分析表明，硅灰石颗粒表面生成水化产物并与水泥浆体形成致密的连生体，该结构对砂浆起到了显著的微筋增强作用；且当掺量达到或超过25%时，硅灰石粉在浆体中形成三维网络骨架。