The Flexural Properties’ Study Of Waste Fiber Recycled Concrete Beam

In recent years, with the constant development of construction industry and manufacturing industry, a lot of waste concrete and waste fibers have been produced. The resulting social and environmental issues became increasingly significant. As a kind of new green concrete for recycling of waste concrete and waste fibers, the research of waste fiber recycled concrete has gradually attracted the attention of the community.As a preliminary study of the flexural properties of waste fiber recycled concrete beam, this paper analyzed the flexural properties of14rectangular cross-section beams with different waste fiber incorporation and recycled aggregate replacement ratio. Volume ratio of the incorporated amount of the waste fibers are0.08%,0.12%,0.16%, fiber length are19mm, recycled aggregate replacement ratio are0,50%,100%.The size of beams are2250mm×150mm×300mm, reinforcement ratio is1.28%. By two symmetrical loading points to concentrated loads, this paper has a preliminary understanding of waste fiber recycled concrete beam’s performance of the force, failure modes and deformation characteristics that under short term loading, and researched and analyzed of waste fiber recycled concrete beams’normal section bearing capacity cracking strength, normal use load of the maximum crack width and deflection. And in accordance with the related formulas in<Code for design of concrete structures> GB50010-2010to analyze the applicability of waste fiber recycled concrete beams’cracking moment, bent ultimate bearing capacity, span deflection, maximum crack width.Through the analysis of the test results, the paper concluded the following main conclusions:(1) Similar with normal concrete suitable reinforcement beam, the waste fiber recycled concrete beams also has4stages witch were elasticity, cracking, yield and ultimate. And during the entire force process, the concrete strain of normal section comply plane section assumption.(2) The waste fiber has obvious resistance cracked, Cracking performance of waste fiber recycled concrete beams equal or exceed the normal concrete beams, test piece cracking late, cracks in the relatively slow development, crack width control capability has improved significantly under the different force stages.(3) The waste fiber has obvious toughening effect. Ductility of waste fiber recycled concrete beams Improved obviously.(4) The bearing capacity of the waste fiber recycled concrete beams has equal or exceed the normal concrete beams. The bearing capacity promote the most When the waste fiber incorporation of0.12%, cracking load increase of approximately9.03%, yield load increase of about7.40%; ultimate bearing capacity increase of about9.75%.(5)<Code for design of concrete structures> GB50010-2010’s applicability analysis shows that, the theoretical calculation of flexural waste fiber recycled concrete beams with the normal section short-term load can be calculated in accordance with the<Code>,the results are safer. (6) Checking for the maximum crack width of the waste fiber recycled concrete beams, the calculated results were too conservative, the proposed amendment was given in this paper as a reference.(7) With the comparison of the flexural performance of the waste fiber recycled concrete beams, and considering the economic benefits, this paper has given a general recommendation for using of the waste fiber recycled concrete in the actual projects in the future.In short, although there are still some inadequacies in this study, overall, the flexural properties’preliminary study of waste fiber recycled concrete beams basically completed. It provided a certain reference for the future continue to study, and also it provided a theoretical basis for the actual projects witch using the waste fiber recycled concrete in the future.