玄武岩纤维复材筋海水海砂混凝土梁抗剪性能  

Shear behavior of BFRP bars reinforced seawater sea-sand concrete beam

作　　者：周锐 朱德举[1,2] ZHOU Rui;ZHU Deju(School of Civil Engineering,Hunan University,Changsha 410082,China;Key Laboratory for Green&Advanced Civil Engineering Materials and Application Technology of Hunan Province,(Hunan University),Changsha 410082,China)

机构地区：[1]湖南大学土木工程学院,湖南长沙410082 [2]绿色先进土木工程材料及应用技术湖南省重点实验室(湖南大学),湖南长沙410082

出　　处：《铁道科学与工程学报》2023年第9期3396-3405,共10页Journal of Railway Science and Engineering

基　　金：国家自然科学基金山东联合基金重点项目(U1806225)。

摘　　要：为了解决沿海城市和岛礁建设中河砂淡水资源短缺、建筑材料运输成本高以及钢筋混凝土结构耐久性不足的问题,同时推动海水海砂资源的有效利用以及深入研究纤维复材筋增强构件的工作性能,开展玄武岩纤维复材筋海水海砂混凝土(BFRP-SSC)梁的抗剪性能研究。采用三点弯曲试验,通过对梁的破坏形式、荷载−挠度关系和抗剪承载力展开讨论,研究剪跨比(剪跨为400,500和600 mm)、养护环境(自然环境和海水浸泡环境)和混凝土碱度(普通SSC和低碱SSC)对梁抗剪性能的影响,并通过拟合试验数据修正了规范的抗剪承载力公式。研究结果表明:剪跨比对BFRP-SSC梁抗剪承载力有显著影响,剪跨比越小的试件其破坏程度越严重;随着剪跨比的增大,BFRP-SSC梁的开裂荷载、极限荷载逐渐减小,极限挠度逐渐增大。在55℃人工海水环境中浸泡60 d后,普通SSC试件的裂缝减少,抗剪承载力下降了33.13%,BFRP箍筋纤维-树脂界面分离;低碱SSC试件的抗剪承载力提高了21.65%,其BFRP箍筋几乎没有降解行为。由于FRP筋混凝土现有设计规范没有考虑剪跨比的影响,理论预测与试验结果相差60%以上;引入与剪跨比相关的参数修正规范公式,修正的公式预测值与试验结果吻合良好。研究结果可以为BFRP-SSC梁的设计和应用提供数据支撑和理论依据。In order to solve the problems of shortage of river sand and freshwater resources,high transportation cost of construction materials and insufficient durability of steel reinforced concrete structures in the construction of coastal cities and islands,and promote the effective utilization of seawater and sea-sand resources and deepen the research on the performance of FRP reinforced structures,the shear behavior of basalt fiber reinforced polymer bars reinforced seawater sea-sand concrete(BFRP-SSC)beams was studied.By using three-point bending test,the effects of shear-to-span ratio(shear span of 400,500 and 600 mm),curing environment(natural environment and seawater immersion environment)and concrete alkalinity(normal SSC and low alkali SSC)on the shear performance of the beams were investigated by discussing the damage form,load-deflection relationship and shear bearing capacity of the beams,and the shear bearing capacity equation in the design code was modified by fitting the test data.The results show that the shear span ratio has a significant impact on the shear bearing capacity of BFRP-SSC beams.The smaller the shear-to-span ratio is,the more severe the damages in the beam are.With the increase of shear span ratio,the cracking load and ultimate load of BFRP-SSC beams decrease gradually,and the ultimate deflection increases gradually.After immersion in 55℃artificial seawater for 60 days,the number of cracks in ordinary SSC specimens become less,the shear bearing capacity is decreased by 33.13%,and the fiber-resin interface in BFRP stirrups is separated.The shear bearing capacity of low alkali SSC specimens is increased by 21.65%,and the BFRP stirrups have almost no degradation.Because the effect of shear span ratio is not considered in the existing design regulations for FRP reinforced concrete,the difference between the theoretical prediction and the test results is more than 60%.When the parameter related to the shearto-span ratio is added to modify the code formulas,and the predicted values by the modif

关 键 词：BFRP 抗剪承载力 剪跨比 低碱海水海砂混凝土 

分 类 号：TU377.9[建筑科学—结构工程]