纤维织物-高延性混凝土加固钢筋混凝土板抗弯性能试验研究

Experimental Study on Flexural Behaviors of Reinforced Concrete Slabs Strengthened with Textile-reinforced Highly Ductile Concrete

为研究纤维织物-高延性混凝土(TR-HDC)加固钢筋混凝土板的抗弯性能,本文对1块对比板、1块高延性混凝土(HDC)加固板、1块纤维织物增强水泥砂浆(TRM)加固板及3块TR-HDC加固板进行四点抗弯试验,研究加固层基体是否添加PVA纤维以及纤维织物层数对钢筋混凝土板破坏形态、荷载-挠度曲线、抗弯承载力、延性以及应变的影响.结果表明:采用TR-HDC加固的钢筋混凝土板,裂缝宽度和间距明显减小,裂缝表现出细而密的特点;TRHDC可以显著提高板的抗弯承载力,开裂、屈服和峰值荷载的最大提升幅度分别为104%、89%和127%;TR-HDC加固层中纤维织物的断裂造成了板延性的降低,因此,实际加固工程中应尽可能避免纤维织物拉断.基于平截面假定,给出了TR-HDC加固钢筋混凝土板的抗弯承载力和挠度计算公式,计算值与试验值吻合较好,可为实际应用提供理论依据.

To investigate the flexural behaviors of RC slabs strengthened with textile-reinforced highly ductile concrete(TR-HDC),the four-point bending test was carried out on one reference slab,one slab strengthened with highly ductile concrete(HDC),one slab strengthened with textile reinforced mortar(TRM)and three slabs strengthened with TR-HDC.The effects of adding with or without PVA fibers and the mumber of layers of textile on the failure modes,load-deflection curves,flexural capacity,ductility factor,and strain analysis were studied.The test results showed that for the RC slabs strengthened with textile-reinforced highly ductile concrete,the cracking width and space of strengthened slabs were reduced apparently,which showed the characteristic of thin and dense.The flexural capacity of RC slabs strengthened with TR-HDC was greatly improved.The maximum increases in the cracking,yield and peak loads were 104%,89%and 127%,respectively.The rupture of the textile in the TR-HDC strengthening layer reduced the ductility of the slabs.Therefore,the textile rupture should be avoided as much as possible in the practical project.Based on the plane section assumption,the formulas for calculating the flexural capacity and deflection of RC slabs strengthened with TR-HDC were proposed.The calculated results were in good agreement with the test results.It can provide the theoretical basis for practical application.