后张无黏结预应力BFRP筋混凝土梁受弯性能试验研究

Experimental Study on Flexural Behavior of Post-tensioned Method Unbonded Prestressed Concrete Beams Reinforced with BFRP Tendons

采用后张法,制作了玄武岩纤维增强塑料筋(BFRP筋)无黏结部分预应力混凝土梁、BFRP筋无黏结全预应力梁以及对比用BFRP筋非预应力梁,对其受弯性能进行对比试验,并对BFRP筋无黏结部分预应力梁中非预应力钢筋的配筋率对受弯性能的影响进行了研究。结果表明,对BFRP筋施加预应力,可以明显提高梁的抗裂度,有效减小梁的挠度和裂缝宽度,改善BFRP筋混凝土梁的正常使用性能;与全预应力梁相比,配置有非预应力钢筋的部分预应力BFRP筋梁的延性更好;且随着非预应力钢筋配筋率的增加,梁的屈服荷载和极限荷载随之提高,裂缝间距、极限裂缝宽度则随之减小。

BFRP tendon reinforced unbonded fullly post tensioned and partially post-tensioned concrete beams were prepared, the differences in the flexural behavior of the concrete beams was studied with non-prestressed bars as references. The influence of reinforcement ratios of non-prestressed steel bars on the flexural behavior of unbonded partially post-tensioned concrete beams was analyzed. It showed that, the cracking resistance, crack width, and deflections of concrete beams were greatly improved by BFRP tendons, resulting in better serviceability. The ductility of partially post-tensioned concrete beams was better than that of fullly post-tensioned beams, and the yield loads and ultimate loads was enhanced as the reinforcement ratios of non prestressed steel bars increased, whereas the crack intervals and ultimate crack width were decreased.