过硫磷石膏矿渣水泥净浆微观力学性能表征

Characterization on Micro Mechanical Properties of Excess-sulfate Phosphogypsum Slag Cement Paste

基于纳米压痕测试,结合解卷积技术、微观力学理论和均匀化方法,分析了过硫磷石膏矿渣水泥(PPSC)净浆的微观力学性能和物相组成,表征了其主要水化产物的力学性质和微观结构。结果表明:在剔除异常数据点后,压痕点的力学性能分布相对集中,大多数压痕点的硬度在1 GPa左右,模量在10 GPa左右和30 GPa左右;PPSC净浆中主要水化产物占比69%,由不同含量的C-S-H凝胶、钙矾石和孔相组成;凝胶相中凝胶颗粒的模量值为56.47 GPa,由C-S-H凝胶颗粒和钙矾石晶体颗粒复合而成,两者含量之比约为3∶1;主要水化产物由低密度凝胶相(η=0.61)和高密度凝胶相(η=0.75)组成,两者对应的凝胶颗粒堆积方式类似球体的随机紧密堆积、六方紧密堆积和面心立方堆积。

Based on nanoindentation test,combined with deconvolution technology,micro mechanics theory and homogenization method,the micromechanical properties and phase composition of excess-sulfate phosphogypsum slag cement(PPSC)paste were analyzed,and the mechanical properties and microstructure of its main hydration products were characterized.The results show that after removing abnormal data points,the mechanical properties of the indentation points are relatively concentrated,with the hardness and the modulus of most indentation points around 1 GPa,10 GPa and 30 GPa,respectively.The main hydration products of PPSC paste accounted for 69%,and the main hydration products are composed of C-S-H gel,ettringite and pore phase with different contents.The modulus of gel particles in the gel phase is 56.47 GPa,which is composed of C-S-H gel particles and ettringite crystal particles with a content ratio of approximately 3∶1.The main hydration products are composed of low-density gel phase(η=0.61)and high-density gel phase(η=0.75),and the corresponding gel particles are stacked in a manner similar to the random compact packing of spheres,hexagonal compact packing and face centered cubic packing.