冻融作用对纤维混凝土韧性和渗水性影响

Research on water permeability and tenacity of fiber concrete influence by freeze-thaw

为探究冻融作用对聚丙烯纤维混凝土韧性和渗水性能的影响,通过EFNARC方板试验和混凝土抗渗等级试验,分析了冻融前后纤维混凝土两种性能的变化规律,试验结果表明:混凝土中掺入聚丙烯纤维能有效的提高变形过程中的能量吸收能力,从而提高混凝土的韧性,并使得原本的脆性破坏形式转换成有征兆的延性破坏形式;纤维掺入量对冻融后混凝土的韧性有不同影响,掺入量在30 kg/m^3以上的纤维混凝土受冻融作用影响较小;冻融作用会降低混凝土的抗渗能力,聚丙烯纤维混凝土在冻融前后均比素混凝土有较好的抗渗能力.

In order to explore the effect of freeze-thaw action on the water permeability and tenacity of polypropylene fiber concrete, this paper analyzed the two kinds change laws of fiber concrete before and after freeze-thaw through EFNARC square plate and concrete permeability test. The test results show that the energy absorption capacity of the concrete in the process of deformation can be effectively improved with adding polypropylene fiber, so as to improve the tenacity of concrete. The original brittle failure form changes into a signed ductile fracture form; the changing amount of polypropylene fiber has a different effect on the tenacity of concrete after freeze-thaw, and concrete that mixes in more than 30 kg/m^3 fiber is affected mildly after freeze-thaw process. Freeze-thaw action will reduce the impermeability of concrete, polypropylene fiber concrete has better impermeability than that of plain concrete both before and after freeze-thaw.