聚丙烯纤维全再生粗骨料混凝土力学性能试验研究

Experimental study on mechanical properties of polypropylene fiber reinforced fully recycled coarse aggregate concrete

为了研究聚丙烯纤维全再生粗骨料混凝土的力学性能,以聚丙烯纤维体积掺量为变化参数,设计制作了36个试件进行立方体与圆柱体单轴抗压及棱柱体抗折试验。观察了试件的破坏过程及形态,获取了圆柱体单轴受压的应力-应变全曲线,分析了聚丙烯纤维掺量对全再生粗骨料混凝土抗压及抗折的力学性能影响。结果表明:掺聚丙烯纤维受压试件破坏时其整体性更好,不掺纤维与掺聚丙烯纤维抗折破坏均为峰值后的脆性破坏;随着聚丙烯纤维掺量的增大,坍落度呈下降趋势,立方体抗压强度持续增大,圆柱体抗压强度先减小后增大;随着聚丙烯纤维掺量的增加,静压弹性模量整体上呈增大趋势,抗折强度持续增大。

In order to study the mechanical properties of polypropylene fiber reinforced fully recycled coarse aggregate concrete,a total of 36 specimens with varying parameter of volume ratio of polypropylene fiber were designed and manufactured for uniaxial compression test of cube and cylinder and bending test of prism.The failure process and modes were observed.And the the stress-strain curves of the cylinder under uniaxial compression were obtained.The influence of volume ratio of polypropylene fiber on mechanical properties of recycled coarse aggregate concrete under uniaxial compression and bending was analyzed.The test result shows that the integrity of compression specimens with polypropylene fiber is better after failure and the flexural failure of the specimens without fiber and with polypropylene fiber is brittle after the peak value.with the increase of volume ratio of polypropylene fiber,the slump presents a downward trend,the cube compressive strength increases continuously,and the cylinder compressive strength decreases first and then increases.With the increase of polypropylene fiber content,the static pressure elastic modulus increases as a whole,and the flexural strength continues to increase.