回收轮胎聚合物纤维混凝土性能试验研究

为研究回收橡胶轮胎聚合物纤维(RTPF)对混凝土工作性能和基本力学性能的影响，对素混凝土(F0)、RTPF和聚丙烯纤维(PPF)混凝土进行拌合物性能测试、基本力学性能试验和纤维作用机理分析.结果表明:含气量随RTPF掺量增大而增大，且相同体积掺量(0.1%)下PPF的引气能力大于RTPF；坍落度随RTPF纤维掺量增大而降低，相同体积掺量(0.1%)下PPF比RTPF混凝土坍落度低；混凝土抗压强度随RTPF纤维掺量增大而降低；RTPF混凝土劈裂抗拉强度和抗折强度均出现了先升高后降低的趋势，RTPF体积掺量0.2%为最优纤维掺量.SEM测试表明，混凝土破坏时RTPF被拔出基体或发生拉断破坏，RTPF可有效提供桥连作用.研究表明RTPF可改善混凝土基本力学性能，并在一定掺量范围内可有效替代PPF.

Experimental Study on Properties of Recycled Tyre Polymer Fiber Reinforced Concrete

To study the effect of recycled rubber tyre polymer fiber (RTPF) on the working performance and mechanical properties of concrete， tests on the properties of the mixtures， the basic mechanical properties and the mechanism of the fiber performances were conducted on the plain concrete (F0)， RTPF concrete and polypropylene fiber (PPF) concrete. The results showed that the air content increases with the increasing of the RTPF fraction， and the air entraining capacity of PPF is better than that of the RTPF with the same volume fraction (0.1%). The slump decreases with the increasing of the RTPF fraction， and the slump of the PPF concrete is lower than that of the RTPF concrete under the same volume fraction (0.1%); the compressive strength of concrete decreases with the increasing of the RTPF fraction. Both the splitting tensile strength and the flexural strength of the RTPF concrete increase at the initially stage and then decrease; 0.2% is determined as the optimal volume fraction. The SEM showed that the RTPF was pulled out from the matrix or broken by tension， which indicates that the RTPF can effectively provide bridging effect. This study showed that the RTPF can improve the mechanical properties of concrete and can replace the PPF effectively within a certain range of the fiber fraction.