考虑不均匀界面时混凝土弹性模量预测  

Prediction of the elastic modulus of concrete with inhomogeneous ITZ

作　　者：郑建军[1] 吕建平[1] 吴智敏[2] 

机构地区：[1]浙江工业大学建筑工程学院,杭州310014 [2]大连理工大学海岸与近海工程国家重点实验室,大连116024

出　　处：《复合材料学报》2008年第5期141-146,共6页Acta Materiae Compositae Sinica

基　　金：国家自然科学基金(50578147);浙江省自然科学基金(Y107638)

摘　　要：提出了考虑不均匀界面时混凝土弹性模量预测的解析法。根据界面层上水泥颗粒的分布特性,给出了界面层上任一点处的局部水灰比和孔隙率。将不均匀界面层划分成一系列同心球壳单元,通过反演方法确定了每个球壳单元和水泥石基体的弹性模量。将三相混凝土分解成一系列两相复合子结构,应用两相复合球模型的正确解导出混凝土弹性模量。通过与文献中的两组实验结果比较验证了本文方法的有效性。数值结果表明,对于给定的骨料体积分数,混凝土弹性模量随着最大水泥颗粒直径和水灰比的增大而减小,但随着最大骨料直径的增大而增大,骨料级配对混凝土弹性模量也有一定的影响。An analytical method is presented for predicting the elastic modulus of concrete with the inhomogeneous interfacial transition zone （ITZ）. Based on the characteristics of distribution of cement grains in the ITZ layer, the local water/cement ratio and porosity at any point in the ITZ layer were given. By dividing the inhomogeneous ITZ into a series of concentric spherical shell elements, the elastic moduli of each spherical shell element and the cement paste matrix were determined through the inverse method. The three-phase concrete was decomposed into a series of two-phase composite substructures. The elastic modulus of concrete was derived by applying the solution for a two- phase composite sphere model. The validity of the method presented in this paper was verified with two sets of experimental results reported in the literature. It demonstrates that, for a given aggregate volume fraction, the elastic modulus of concrete decreases with the increase of the maximum cement diameter and water/cement ratio, but increases with the increase of the maximum aggregate diameter. The aggregate gradation also has a certain influence on the elastic modulus of concrete.

关 键 词：混凝土 不均匀界面 弹性模量 水灰比 最大骨料直径 最大水泥颗粒直径 

分 类 号：TU528.01[建筑科学—建筑技术科学]