| Multi-scale polypropylene fiber concrete is an innovative field of fiber concrete，which can improve and enhance the concrete by mix-doping the different aspect ratiopolypropylene with concrete,so as to reach the mutually reinforcing purpose.In this paper, the author mainly investigated the fine, thick and multi-scalepolypropylene fiber’s early-age shrinkage, mechanical properties and workability, andsimulated temperature filed and temperature stress by ABAQUS software. In thisdissertation, the main original work includes:①Based on the study of fiber-reinforced mechanism, the paper is mainlyinvestigated the early-age crack resistance of different kinds of polypropylene fiber andmulti-scale polypropylene fiber at the same weight fraction, and find the optimal fiber.②Based on the different kinds of direct tensile test methods of concrete in thepresent studies, the paper used a glued double-plated grip method to carry out theuniaxial tensile test, in order to present the effects of different kinds of polypropylenefiber’s and multi-scale polypropylene fiber’s tensile strength, peak strain and elasticitymodulus, under the optimal weight fraction.③About axial compressive experiment, the influence of single and multi-scalepolypropylene fiber concrete on the cubic compressive strength and elasticity modulusis studied. After incorporation of polypropylene fiber, the cohesiveness and waterretention have differently improved and the slump of concrete has differently decreased.④Shotcrete has been widely used in tunnel bolting and shotcreting support project,but less used in the field of slope support projects. In comparison with the plainshotcrete, crack of polypropylene fiber shotcrete is effectively reduced. Finally, thethesis simulated temperature filed and temperature stress by ABAQUS software.Theresult shows that multi-scale polypropylene fiber and single polypropylene fiber all canfully improve crack resistance ability. |
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