钢筋和FRP筋混合配筋ECC-混凝土复合梁受弯性能试验研究

Experimental study on flexural behavior of steel and FRP hybrid reinforced ECC⁃concrete composite beams

为研究钢筋和FRP筋混合配筋ECC-混凝土复合梁受弯性能,制作了4组不同配筋类型的混凝土梁共16根进行受弯性能试验研究,每组为4根不同ECC替代高度试件。研究了配筋类型(钢筋和FRP筋各一组,钢筋和FRP筋混合配筋2组)和截面类型(混凝土梁、ECC-混凝土复合梁和ECC梁)对承载能力、变形、裂缝和破坏形态的影响。结果表明,ECC与混凝土具有良好的粘结性能;用受拉性能好的ECC替代混凝土以及采用混合配筋提高梁在弯曲荷载作用下抵抗变形和裂缝发展的能力,且抵抗能力随着ECC高度替代率和配筋截面含钢率的提高而增大;ECC基体中纤维具有良好的桥接作用,可实现ECC梁弯曲破坏时仅发生基体压碎,不产生崩裂。

In order to investigate the flexural behavior of steel and FRP hybrid reinforced engineered cementitious composite(ECC)⁃concrete composite beams,four groups of different reinforcement type,a totally 16 concrete beams,were made and tested by flexural behavior experimental study,and one group has four specimens with different ECC replacement height.The effects of reinforcement type(one group reinforced with FRP bars,one with steel bars,and two groups hybrid reinforced with steel and FRP bars)and cross⁃section type(concrete beam,ECC⁃concrete composite beam and ECC beam)on the bearing capacity,deflection,crack and failure pattern were studied.The results show that the bonding between the ECC and concrete is good.Using ECC with good tensile performance replace concrete and hybrid reinforcement can effectively enhance the ability to resist deformation and crack.And the resist ability increases with the increase of ECC replacement height and the area ratio of steel to whole reinforcement.The fibers distributed in the ECC matrix have good bridging effect,result in the matrix crushing but no rupture occurred in the bending failure of ECC beam.