Cui Tao, He Haoxiang, Yan Weiming
Beijing Key Laboratory of Earthquake Engineering and Structural Retrofit, Beijing University of Technology, Beijing 100124, China.
Materials (Basel). 2019 Jul 25;12(15):2370. doi: 10.3390/ma12152370.
In order to establish accurate compressive constitutive model of Hybrid Fiber-Reinforced Concrete (HFRC), 10 groups of HFRC specimens containing polyvinyl alcohol (PVA), polypropylene (PP), and steel fibers are designed and compressive testing is conducted. On the basis of summarizing and comparing the existing research, accuracy of various stress-strain constitutive model is compared and the method of calculating fitting parameters is put forward, peak stress, peak strain, and elastic modulus of specimens with different fiber proportion are analyzed, the calculation expressions of each fitting parameter are given. The results show that, under the condition that the volume of the hybrid fiber is 2% with the proportion of the steel fiber increase, the strength of the specimen increases, the peak strain decreases slightly, and the elastic modulus increases significantly. In specimens mixed with PVA-PP hybrid fiber, with the increase of PVA fiber proportion, the peak stress and elastic modulus of the material are improved, and the peak strain are decreased. The existing stress-strain expressions agree well with the tests. Accuracy of exponential model proposed in this paper is the highest, which can be applied in engineering and nonlinear finite element analysis of components.
为建立混杂纤维混凝土（HFRC）精确的抗压本构模型，设计了10组包含聚乙烯醇（PVA）、聚丙烯（PP）和钢纤维的HFRC试件，并进行了抗压试验。在总结和比较现有研究的基础上，对比了各种应力-应变本构模型的精度，提出了拟合参数的计算方法，分析了不同纤维掺量试件的峰值应力、峰值应变和弹性模量，给出了各拟合参数的计算表达式。结果表明，在混杂纤维体积为2%的条件下，随着钢纤维掺量的增加，试件强度提高，峰值应变略有降低，弹性模量显著增大。在PVA-PP混杂纤维掺量的试件中，随着PVA纤维掺量的增加，材料的峰值应力和弹性模量提高，峰值应变降低。现有应力-应变表达式与试验结果吻合良好。本文提出的指数模型精度最高，可应用于工程及构件的非线性有限元分析。
