氯离子侵蚀下混合纤维增强钢筋混凝土损伤规律

Damage law of mixed fiber reinforced concrete under chloride ion erosion

混合纤维增韧混凝土具有很好的耐久性。针对PVA和UPE混合纤维混凝土,采用高浓度氯离子溶液进行120 d侵蚀试验,并结合三维数值模拟技术,预测分析氯离子侵蚀前后钢筋混凝土梁的承载力和损伤变化规律。结果表明,无纤维混凝土和纤维体积含量为0.2%(其中0.1%PVA和0.1%UPE)的混凝土受海水侵蚀后脆性增加,峰值应力和对应的应变减小;但掺加纤维能降低混凝土梁遭受氯离子侵蚀的抗弯曲承载能力的损失率和峰值应力对应的应变损失率,同时增加梁的韧性;加载位移为20 mm时,海水侵蚀后有纤维的梁最终拉伸损伤比无纤维的梁最终拉伸损伤减小4.9%,最终压缩损伤比无纤维的梁最终压缩损伤减小16.2%。

Mixed fiber concrete has good durability.Aiming at the PVA and UPE mixed fiber concrete,we carry out the 120 d corrosion test by high concentration chloride solution,predict and analyze the bearing capacity and damage change law of reinforced concrete beams before and after chloride ion corrosion combined with the three-dimensional numerical simulation technology.The results show that the brittleness of non-fiber concrete and concrete with 0.2%fiber(0.1%PVA and 0.1%UPE)volume content increases after being eroded by sea water,peak stress and corresponding strain decrease.However,the addition of fiber can reduce the loss rate of the flexural bearing capacity and the strain loss rate corresponding to peak stress of the concrete beam subjected to chloride ion erosion,and increase the toughness of the beam.When the loading displacement is 20mm,the final tensile damage of the beam with fibers after seawater erosion is 4.9%less than the final tensile damage of the fiber-free beam.And the final compression damage of the beam with fibers is 16.2%less than the final compression damage of the fiber-free beam.