跨尺度模拟硬化水泥净浆力学性能:微观物相的影响  

Modeling the mechanical properties of cement paste:Effect of different phases

作　　者：高翔[1,2] 魏亚[2] 黄卫[1] GAO Xiang;WEI Ya;HUANG Wei(Ministry of Education ITS Engineering Research Center, Southeast University, Nanjing 210096,China;Key Laboratory of Civil Engineering Safety and Durability of China Education Ministry, Department of Civil Engineering, Tsinghua University, Beijing 100084, China)

机构地区：[1]东南大学教育部智能运输系统研究中心,南京210096 [2]清华大学土木工程系土木工程安全与耐久教育部重点实验室,北京100084

出　　处：《复合材料学报》2018年第5期1339-1348,共10页Acta Materiae Compositae Sinica

基　　金：国家自然科学基金(51578316;51778331)

摘　　要：采用纳米压痕实验测量硬化水泥净浆中未水化物、水化产物和孔隙等微观物相的力学性能,并基于背散射电镜(BSE)图像的灰度分析计算各微观物相的含量。在得到各微观物相含量和力学性能的基础上,针对水泥净浆的弹性模量进行均一化建模,并讨论各微观物相及其模量的选取对跨尺度模拟硬化水泥净浆力学性能的影响。通过微米压痕的实测净浆模量验证模型及参数选取的可靠性。提出在硬化水泥净浆力学性能的多尺度模型中,需要选取12GPa作为孔隙有效模量,并将水化产物划分为低密度的水化硅酸钙凝胶(LD-CSH)和高密度的水化硅酸钙凝胶(HD-CSH)两种物相,而不同种类的未水化物可被视作一种物相。在此基础上,使用Mori-Tanaka模型或自洽模型计算得到的净浆模量与实测净浆模量吻合。The mechanical properties and the fractions of individual phases at microscale were measured by nanoindentation and back scattered electron（BSE）image analysis,and they can be used as the input in modeling the mechanical properties of cement paste.The mechanical properties of cement paste were measured by microindentation.The effect of individual phases on the effective modulus of hardened cement paste was quantified by comparing the measured and homogenized paste modulus.It is found that the effective modulus of pore needs to be set to 12 GPa as input for homogenization.Meanwhile,the high density hydrated calcium silicate gel（HD-CSH）and the low density hydrated calcium silicate gel（LD-CSH）need to be viewed as two different phases in modeling.Whereas,different clinkers can be regarded a single phase.The effective paste moduli calculated by both Mori-Tanaka scheme and selfconsistent scheme agree well with the measured paste modulus.

关 键 词：硬化水泥净浆 弹性模量 仪器化压痕 孔隙有效模量 多尺度模型 

分 类 号：TB321[一般工业技术—材料科学与工程]