混杂纤维再生混凝土力学性能试验研究

Experimental Study on Mechanical Properties of Recycled Coarse Aggregate Concrete with Hybrid Fibers

摘要: 考虑到再生混凝土存在强度低等固有缺陷，可考虑采用掺纤维的方式改善其力学强度。为了研究纤维对RAC性能的改善效果，本文选取低弹性模量的聚丙烯纤维和高弹性模量的钢纤维，以混掺的方式掺入RAC中，研究了纤维掺量对RAC立方体抗压、劈裂抗拉、抗折强度和轴心抗压强度的影响。试验结果表明：混杂掺入钢、聚丙烯纤维均提高RAC的抗压、劈裂抗拉、抗折和轴心抗压强度；与单掺聚丙烯纤维相比，混合掺入钢、聚丙烯纤维对RAC的改善效果较佳，在聚丙烯纤维体积掺量为0.1%和钢纤维体积掺量为1.0%时，混杂纤维再生混凝土表现出较好的增强效果。

Abstract: Considering the inherent defects such as low strength of recycled aggregate concrete (RAC), fiber incorporation can be adopted to modify its mechanical properties. To investigate the improvement effect of fibers on RAC performance, this study selected polypropylene fibers with low elastic modulus and high-elastic-modulus steel fibers, which were mixed into RAC in a hybrid form. The influence of fiber hybridization on the cubic compressive strength, splitting tensile strength, and flexural and axial compressive strength of RAC was analyzed. The results show that the incorporation of steel fibers and polypropylene fibers can enhance the cubic compressive strength, splitting tensile strength, and flexural and axial compressive strength of RAC. Compared with single polypropylene fiber, the hybrid incorporation of steel fibers and polypropylene fibers yields a better improvement effect on RAC. Within the scope of the test, when the steel fiber volume fraction is 0.1% and the polypropylene fiber volume fraction is 1.0%, the hybrid fibers exhibit a superior reinforcement effect on the performance of RAC.