BFRP筋回收轮胎钢纤维混凝土短柱偏压性能试验

Eccentric compression performance test of BFRP bar recycled tire steel fiber reinforced concrete short column

提出了玄武岩筋回收轮胎钢纤维混凝土(BRC)短柱新型材料构件,为研究BRC短柱偏压性能,制作6根混凝土短柱,并结合非接触式全场应变位移测量技术-数字图像(3D-DIC)技术进行试验测量,研究了回收轮胎钢纤维(RTSF)体积掺量和偏心距对短柱偏压性能和破坏模式的影响.研究结果表明:BRC短柱受压破坏为混凝土压碎、玄武岩纤维增强复合材料(BFRP)筋压断破坏,RTSF提高了混凝土短柱的受压性能,对限制试验柱裂缝和变形的发展具有显著作用,并能有效提高其开裂荷载、极限荷载、混凝土极限压应变和抗压强度.在相同偏心距下,与玄武岩筋普通混凝土短柱相比,BRC混凝土短柱的开裂荷载分别提高了20.46%,23.19%和38.36%,极限承载力分别提高了15.39%,21.55%和30.69%.由于现有的计算模型不足以准确计算BRC短柱受压承载力,提出了考虑RTSF混凝土抗拉强度的承载力计算模型,BRC短柱试验值与预测值符合较好.

A new material component of basalt bar recycled tire steel fiber concrete(BRC)short column was proposed.In order to study the eccentric compression performance of BRC short columns,six concrete short columns were fabricated.Combined with non-contact full-field strain displacement measurement technology-digital image(3D-DIC)technology,experimental measurements were carried out to study the effects of volume content and eccentricity of recycled tire fiber(RTSF)on the eccentric compression performance and failure mode of short columns.The results show that the compressive failure of BRC short columns is caused by concrete crushing and basalt fiber reinforced composite(BFRP)reinforcement breaking under compression.RTSF improves the compressive performance of concrete short columns,plays a significant role in limiting the development of cracks and deformation of test columns,and can effectively improve its cracking load,ultimate load,ultimate compressive strain and compressive strength of concrete.Under the same eccentricity,compared with basalt reinforced ordinary concrete short columns,the cracking load of BRC concrete short columns increase by 20.46%,23.19%and 38.36%respectively,and the ultimate bearing capacity increase by 15.39%,21.55%and 30.69%respectively.Because the existing calculation model is not enough to accurately calculate the compressive bearing capacity of BRC short columns,a calculation model of bearing capacity considering the tensile strength of RTSF concrete was proposed.The test values of BRC short columns are in good agreement with the predicted values.