纤维改性重载路基混凝土的试验研究

Experimental Study of Fiber Modified Heavy Haul Subgrade Concrete

针对传统重载铁路路基混凝土韧性差的问题,提出通过纤维对路基混凝土进行改性,增强路基混凝土的韧性,并对改性后混凝土性能进行研究。试验结果表明,钢纤维和聚丙烯腈纤维掺量分别为0.6%和0.2%时混凝土性能最佳,此时混凝土抗压和劈裂抗拉强度分别为57.8MPa和6.5MPa。混凝土受荷载影响时,纤维在混凝土内部发挥协同作用、跨越裂缝、连接集料,抑制了裂缝的萌生和发展。同时纤维与骨料缠结,在混凝土内部形成支撑,增强了混凝土的整体性,因此在受荷载作用时,不会出现脆性断裂、大面积脱落的情况,表现出良好的强度和韧性。

In view of the poor toughness of the traditional heavy haul railway subgrade concrete,this paper puts forward that the subgrade concrete was modified by fiber to enhance the toughness of the subgrade concrete,and the performance of the modified concrete was studied.The test results show that when the content of steel fiber is 0.6%and the content of polyacrylonitrile fiber is 0.2%,the performance of concrete is the best.Among them,the compressive strength of concrete is 57.8MPa,and the splitting tensile strength of concrete is 6.5MPa.When the concrete is affected by the load,the fibers play a synergistic role in the concrete,across the crack,connect the aggregate,and inhibit the initiation and development of cracks.At the same time,fiber and aggregate are entangled to form a support inside the concrete,which enhances the integrity of the concrete.Therefore,when the concrete subjects to load,there is no brittle fracture and large-area falling off,showing good strength and toughness.