Strukar Kristina, Kalman Šipoš Tanja, Dokšanović Tihomir, Rodrigues Hugo
Faculty of Civil Engineering and Architecture Osijek, Department for Technical Mechanics, Vladimira Preloga 3, Osijek HR-31000, Croatia.
Faculty of Civil Engineering and Architecture Osijek, Department for Materials and Structures, Vladimira Preloga 3, Osijek HR-31000, Croatia.
Materials (Basel). 2018 Nov 11;11(11):2245. doi: 10.3390/ma11112245.
Inclusion of rubber into concrete changes its behavior and the established shape of its stress-strain curve. Existing constitutive stress-strain models for concrete are not valid in case of rubberized concrete, and currently available modified models require additional validation on a larger database of experimental results, with a wider set of influential parameters. By executing uniaxial compressive tests on concrete with rubber substituting 10%, 20%, 30%, and 40% of aggregate, it was possible to study and evaluate the influence of rubber content on its mechanical behavior. The stress-strain curve was investigated in its entirety, including compressive strength, elastic modulus, strains at significant levels of stress, and failure patterns. Experimental results indicated that increase of rubber content linearly decreases compressive strength and elastic modulus, but increases ductility. By comparing experimental stress-strain curves with those plotted using available constitutive stress-strain models it was concluded that they are inadequate for rubberized concrete with high rubber content. Based on determined deviations an improvement of an existing model was proposed, which provides better agreement with experimental curves. Obtained research results enabled important insights into correlations between rubber content and changes of the stress-strain curve required when utilizing nonlinear material properties.
在混凝土中掺入橡胶会改变其性能以及应力-应变曲线的既定形状。现有的混凝土本构应力-应变模型对于橡胶混凝土并不适用，目前可用的改进模型需要在更大的实验结果数据库上进行额外验证，且要有更广泛的影响参数集。通过对用橡胶替代10%、20%、30%和40%骨料的混凝土进行单轴压缩试验，得以研究和评估橡胶含量对其力学性能的影响。对应力-应变曲线进行了全面研究，包括抗压强度、弹性模量、显著应力水平下的应变以及破坏模式。实验结果表明，橡胶含量的增加会使抗压强度和弹性模量线性降低，但会提高延性。通过将实验应力-应变曲线与使用现有本构应力-应变模型绘制的曲线进行比较，得出这些模型对于高橡胶含量的橡胶混凝土并不适用的结论。基于确定的偏差，提出了对现有模型的改进，该改进与实验曲线的吻合度更好。获得的研究结果使人们能够深入了解橡胶含量与利用非线性材料特性时应力-应变曲线变化之间的相关性。
