水泥砂浆塑性收缩开裂本构方程初探  

Preliminary Research on Constitutive Equation of Plastic Shrinkage Cracking for Cement Mortar

作　　者：张志亮[1] 马一平[1] 王培铭[1] 杨晓杰[1] 

机构地区：[1]同济大学先进土木工程材料教育部重点实验室,上海200092

出　　处：《材料导报（纳米与新材料专辑）》2008年第3期180-183,186,共5页

基　　金：国家重点基础研究发展规划项目(2009CB623104)

摘　　要：采用自行设计的塑性抗拉强度及塑性毛细管收缩应力测试装置分别测试了不同灰砂比和不同聚乙烯醇纤维掺量时砂浆的塑性抗拉强度及塑性毛细管收缩应力,对实验结果进行了线性回归分析。结果表明,当抗裂指数K大于1.62时,试件不开裂,当K值小于1.38时,试件开裂,当K值介于1.38和1.62之间时,试件有一定概率开裂。灰砂比和纤维掺量对塑性抗拉强度以及塑性毛细管收缩应力的线性影响是显著的,抗裂指数关于灰砂比及纤维掺量的本构方程分别为K_(c/s)=(-0.00207R_(c/s)+0.0383)/(0.00879R_(c/s)+0.0227)和K_f=(0.00379V_f+0.0359)/(-0.00373V_f+0.0345)。经实验检验,这2个方程的计算结果与实验结果相吻合。The plastic tensile strength and the plastic shrinkage capillary stress of mortar with different cement-sand ratios and different PVA fiber volumes are investigated by the use of a self-designed measuring device. The results are analyzed by the method of linear regression. The results show that the testing model doesn＇t crack when the plastic shrinkage cracking index is more than 1.62,while the testing model cracks when the plastic shrinkage cracking index is less than 1.38 ; the testing model may crack according to a certain probability when the plastic shrinkage crack- ing index is between 1.38 and 1.62. The linear effects of the cement-sand the ratio and the fiber volume on the plastic tensile strength and the plastic shrinkage capillary stress are notable. The constitutive equations of the plastic shrinkage cracking index to the cement-sand ratio and the fiber volume are Kc/s=-0.00207Rc/s＋0.0383/0.00879Rc/s＋0.0227和Kf=0.00379Vf＋0.0359/-0.00373Vf＋0.0345,respectively, which are identical with the test results.

关 键 词：塑性抗拉强度 塑性毛细管收缩应力 抗裂指数 本构方程 水泥砂浆 

分 类 号：TB301[一般工业技术—材料科学与工程] TU528.58[建筑科学—建筑技术科学]