结合M-T均匀化理论的钢纤维混凝土路面力学性能研究

Research on mechanical properties of steel fiber reinforced concrete pavement combined with M-T homogenization theory

钢纤维混凝土作为1种纤维增强水泥基复合材料,其宏观力学性能取决于真实微观结构。当前多采用试验测试得到其宏观弹性模量,成本高、离散性大、耗时长。运用Mori-Tanaka均匀化理论和细观有限元分析预测钢纤维掺量为0、0.5%、1%、1.5%、2%的钢纤维混凝土宏观弹性模量。针对某实际工程路面结构,建立三维有限元模型,根据混凝土配合比结合M-T均匀化理论预测钢纤维混凝土面层的宏观弹性模量,分析了钢纤维掺量、板厚、轴重等因素对路面板应力、应变和路表弯沉的影响。结果表明,钢纤维混凝土弹性模量预测值和试验结果吻合很好,钢纤维掺量对路面板板底最大拉应力、拉应变的影响较小,对路表弯沉值的影响很小,路面板厚度对其影响均较大,轴重对其影响最大。提出了结合均匀化细观理论和有限元方法研究钢纤维混凝土路面宏观力学性能的方法框架,供工程设计和分析参考。

Steel fiber reinforced concrete is a kind of cement-based composite material enhanced with fibers.Its macro-mechanical properties rely on its actual microstructure.Now the dominant method to obtain the material′s macro elasticity modulus is through tests,which are costly,time-consuming and have high discreteness.Mori-Tanaka homogenization theory and mesoscopic finite element method are used to estimate the macro elasticity modulus of steel fiber reinforced concrete,with steel fiber dosage of 0,0.5%,1%,1.5%and 2%,respectively.3D FE model was established referring to the pavement structure of a certain project.The macro elasticity modulus of steel fiber reinforced concrete pavement was predicted combining the concrete mixing proportion and M-T homogenization theory.How such factors including steel fiber dosage,slab thickness and axle load may affect the stress,strain,and deflection of the pavement structure were analyzed.The findings show that the predicted value of elastic modulus of steel fiber reinforced concrete coincides well with that obtained from tests.The steel fiber dosage plays little role in affecting the maximum tension stress and tension strain of the pavement slab bottom,as well as the pavement deflection.Whereas the slab thickness can affect all these factors to a larger degree,and the axle load has the greatest impact upon them.The method frame proposed combining homogenization mesoscopic theory and FE method to study the macro-mechanical properties of steel fiber concrete pavement,can shine some light for engineering design and analysis.