BFRP筋吸水树脂混凝土板静力抗弯性能试验研究

Flexural behavior of BFRP bar reinforced cellular concrete slabs fabricated with saturated super absorbent polymers

为研究BFRP筋吸水树脂混凝土板的静力抗弯性能,对其静态力学抗弯特性、裂缝扩展规律、破坏模式、挠曲变形及应力应变曲线进行静载试验研究。结果表明:抗弯刚度是导致试样静载力学行为不同的关键因素,3种试件抗弯刚度大小差异明显,即SP板>BP板>BS板。由于钢筋是弹塑性材料,BFRP筋是线弹性材料,试件BS和BP呈弹性变形和破坏失效两阶段破坏模式;试件SP在混凝土开裂和钢筋屈服后,抗弯刚度逐渐小于BP试件,破坏前有显著的延性变形,最终呈弯曲破坏模式。试件BS、BP的整体挠曲变形大,残余变形小,开裂特征显著。同时,由于骨料咬合力和销栓力的不足,其更容易发生剪切破坏且脆性特征显著。

BFRP bar reinforced cellular concrete slabs fabricated with saturated super absorbent polymers were subjected to static three-point bending to investigate its mechanical characteristics,crack propagation law,failure mode,flexural deformation and local strain.The results showed that the flexural stiffness was the key factor leading to the different behaviors.Three types of specimens obtained different flexural stiffness which was SP>BP>BS.Since the elastic-plastic property of steel bars and linear elastic property of BFRP bars,the BS and BP demonstrated a two-stage failure mode with elastic deformation and failure.After cracking of concreteand yielding of steel bar,the flexural stiffness of SP gradually decreased and became smaller than that of BP with significant ductile deformation before bending failure.The BS and BP gained large flexural deflection,small residual deflection and significant cracking.Meanwhile,due to the lack of aggregate interlock and dowel effects of reinforcements,specimens were more likely to shear failure with obvious brittle characteristics.