Study On The Mechanical Propertise Of Polypropylene Fiber Reinforced Self-compacting Concrete Beam

The quality of common concrete products is greatly affected by the proficiency of workers’ operation and many complex object features are likely to result in the non-compactness of concrete. Excessive or inadequate vibration is easy to appear in the vibration of concrete. All these will reduce the stress performance of concrete. Under many circumstances, reinforced concrete structure will need reinforcement maintenance or be abandoned in advance because of the reduction of the concrete’s durability and security causing by cracks. Now, using fiber to reinforce the mechanical property and anti-cracking ability of concrete and depending on the self compacting property of concrete to avoid the effects on the quality of concrete products under construction has become a concerned research area. However, when exploring and studying the fiber reinforced self-compacting concrete, the academic focus point is usually put on the inflexible fiber reinforced self-compacting concrete and the emphasis on the flexible fiber reinforced self-compacting concrete is less. At present, mature research results of polypropylene fiber reinforced self-compacting concrete are mainly used in the workability and strength and researches on the fiber’s effects on the cracks are usually used in non-structural applications such as the prevention of early cracks, which lack systematicness.Through lots of studies on mix proportion, this article has found the mix proportion of polypropylene fiber reinforced self-compacting concrete which can meet the demand of self compacting property. Then, it conducts researches on how polypropylene fiber of different volume contents and slenderness ratio affects the working performance and mechanical performance of self-compacting concrete. Based on this, research on the bending property of 19 mm polypropylene fiber-reinforced self-compacting concrete rectangle beam of 0.15% volume content is carried on. It is compared with the bending properties of 12 mm polypropylene fiber-reinforced self-compacting concrete beam of 0.15% volume content and common reinforced self-compacting concrete beam. Main researches are the following:①Comprehensively reference standard suggestions related to self-compacting concrete and contents of relevant research papers of same category. Conduct tests on the working performance of polypropylene fiber-reinforced self-compacting concrete mixture of different volume contents and slenderness ratio by using slump flow test, L-shaped meter test, V-shaped funnel test and segregation resistance test to analyze the effects of fiber content and slenderness ratio on the working performance of concrete mixture. Finally gain the polypropylene fiber reinforced self-compacting concrete that whose volume content can reach 0.2% at most.②Conduct the mechanical test on polypropylene fiber reinforced self-compacting concrete which meets the self compacting properties and analyze the cubic compressive strength, axial compressive strength, static modulus of elasticity, splitting tensile strength and the folding strength of the polypropylene fiber reinforced self-compacting concrete with different volume contents and slenderness ratios. Top out the mixing proportion of TF19V15 and TF12V15 to conduct the experiment of the flexural behavior of the reinforced concrete rectangular beam.③Experimentally research on the bending strength of reinforced self-compacting concrete rectangular beam of polypropylene fiber with volume content of 19mm0.15% and 12mm0.15%, analyze the influence of two polypropylene fibers with the same volume content on the concrete beams’ cracking load, yield load, ultimate load, fracture morphology, bend ductility, mid-span deflection and the curve of the relation between mid-span bar strain and its load, and illustrate whether the intersecting surface of polypropylene fiber reinforced self-compacting concrete beam is consistent with the assumption of plane section.④Utilize ANSYS to touch and conduct the material nonlinear snalysis on the reinforced self-compacting concrete rectangular beam of polypropylene fiber with volume content of 19mm0.15% and 12mm0.15%, compare the experimental study and numerical analysis results and give the the first principal stress contour of concrete beams and the reinforced axial stress diagram to show the changes of stress distribution of polypropylene fiber reinforced self-compacting concrete and steel in the loading path under symmetrical two loads.The research shows that polypropylene fiber could effectively optimize the bending strength, bending ductility, fracture morphology and the bar strained conditions of the beams and therefore reasonably speculate that polypropylene fiber reinforced self-compacting concrete beam has better structure in carbonation resistance ability and durability than ordinary self-compacting concrete.