高石粉含量下C80混凝土力学性能数值模拟研究

Numerical Simulation Study on Mechanical Properties of C80 Concrete with High Stone Powder Content

为研究石粉含量和纤维掺量对C80混凝土基本力学性能(包括立方体抗压强度、轴心抗压强度、抗折强度、劈裂抗拉强度和弹性模量)的影响,结合Digimat和Abaqus建立2D随机骨料模型、3D纤维混凝土细观模型,将不同石粉含量、纤维掺量下混凝土的数值模拟与同等条件下基本力学试验结果进行对比分析。结果显示:2D随机骨料模型中过高(石粉含量大于5%时称为高石粉含量)的石粉含量会降低混凝土的整体力学性能,石粉含量越低模拟值与试验值越接近,当石粉含量为5%时混凝土的整体力学性能达到最佳。3D纤维混凝土细观模型中不同纤维类型对高石粉含量混凝土的强度有不同影响,与玄武岩纤维相比,铜镀纤维的掺入对高石粉含量下混凝土力学性能的增幅更明显。铜镀纤维体积掺量为0.4%和0.6%时均能提高混凝土力学性能,当掺量为0.6%时,混凝土数值模拟与试验结果误差小于7.1%且力学性能达到最优;玄武岩纤维混凝土的抗压性能随纤维体积掺量的增加而降低,当掺量为0.03%时数值模拟结果与试验结果误差范围在0.4%-8.7%,但对混凝土整体力学性能的提升较小。

In order to study the effects of stone powder content and fiber content on the basic mechanical properties of C80 concrete(including cube compressive strength, axial compressive strength, flexural strength, splitting tensile strength and elastic modulus), 2D random aggregate model and 3D fiber concrete meso model were established by combining Digimat and Abaqus, the numerical simulation of concrete under different stone powder content and fiber content was compared with the basic mechanical test results under the same conditions. Results show these as follows. In 2D random aggregate model, high stone powder content(when stone powder content is greater than 5%, it is called high stone powder content) will reduce the overall mechanical properties of concrete. The lower the stone powder content is, the closer the simulated value is to the experimental value. When stone powder content is 5%, the overall mechanical properties of concrete reach the best. In the 3D fiber concrete meso-model, different fiber types have different effects on the strength of concrete with high stone powder content. Compared with basalt fibers, the addition of copper-coated fibers creates a more positive effect in the mechanical properties of concrete with high stone powder content. The mechanical properties of concrete can be enhanced by adding 0.4% and 0.6% copper-coated fibers. When the fiber volume content is 0.6%, the error between numerical simulation and experimental results is less than 7.1%, and the mechanical properties of concrete are optimal. The compressive properties of basalt fiber concrete decrease with the increase of fiber volume ratio. When the fiber volume ratio is 1 kg/m~3, the error range between numerical simulation results and experimental results is 0.4%~8.7%, but the improvement of the overall mechanical properties of concrete is small.