BFRP筋再生混凝土梁抗弯性能试验研究

通过7根玄武岩纤维(BFRP)筋再生混凝土梁和1根钢筋再生混凝土梁的抗弯性能试验,研究了不同纵筋配筋率与再生骨料取代率对BFRP筋再生混凝土梁受弯性能的影响,分析其承载力变化过程、破坏形态、挠度变形与裂缝发展情况,并与钢筋再生混凝土梁进行对比。结果表明,BFRP筋再生混凝土梁的破坏形式有少筋和超筋破坏两种,分别由BFRP筋拉断和受压区再生混凝土压碎控制。合理配筋的BFRP筋再生混凝土梁破坏前产生的挠度较大,且受拉BFRP筋的应变也较大,说明合理配筋的BRPP筋再生混凝土梁具有一定的延性,能较好地发挥两种材料的性能。BFRP筋再生混凝土梁的裂缝宽度和裂缝条数受再生骨料取代率影响较小,而受配筋率影响较大。此外,BFRP筋再生混凝土梁的初裂荷载相比钢筋再生混凝土梁略低,但极限荷载却有明显提高。

EXPERIMENT STUDY ON THE FLEXURAL BEHAVIOUR OF BFRP REINFORCED RECYCLED AGGREGATE CONCRETE BEAMS

This paper experimentally investigated the flexural behaviour of basalt fiber-reinforced polymer (BFRP) reinforced recycled aggregate concrete (RAC) beams. A total of eight RAC beams, including seven reinforced with BFRP and one reinforced with steel, were fabricated and tested. The paper studied the effect of the different longitudinal reinforcement ratios and replacing rate of recycled aggregate concrete on the flexural behaviour of BFRP reinforced recycled aggregate concrete beams. The flexural capacity, failure mode, flexibility deformation and crack distribution of the test beams were analyzed. The results indicate that the failure mode was under-reinforced failure or over-reinforced failure which was governed by BFRP rupture or concrete crushing, respectively. The BFRP reinforced RAC beams with reasonable reinforcement ratio would produce larger deflection deformation and strain of BFRP tendons than that of steel reinforced RAC beam before the failure. The results indcate that the BFRP rein forced RAC beam could play a good performance of the two materials with a certain degree of ductility. Compared with the replacement rate of recycled aggregates, the reinforcement ratio had a larger influnce on the width and number of cracks in BFRP reinforced RAC beams. Furthermore, it has found that the initial cracking load of BFRP reinforced RAC beams was slightly lower than steel reinforced RAC beam. Whereas, the ultimate load was improved obviously.