GFRP筋混凝土梁抗爆性能试验研究与数值分析

玻璃纤维增强聚合物(GFRP)筋具有耐腐蚀、抗拉承载力高等优点.它们可作为混凝土防护结构的纵筋而代替钢筋.为了明确GFRP筋混凝土梁(GRCBs)的抗爆性能,对GFRP筋混凝土梁和钢筋混凝土梁(SRCBs)进行了爆炸试验、四点弯曲静力试验及数值模拟分析.结果表明:四点弯曲静力试验中,工况是3kg-0.65m的爆炸荷载作用后相同等效刚度设计的GRCBs承载力是SRCBs的5.5倍.在近距离爆炸作用下(比例爆距小于0.5159mkg^-3),由于GFRP筋处于弹性阶段,破坏形式主要是混凝土出现裂纹、剥落和震塌.通过数值模拟分析,增加纤维增强聚合物(FRP)筋刚度可以降低GRCBs跨中位移,跨中最大位移降低率与EA比的比值为0.1,减少GRCBs的裂纹与损伤,增强GRCBs的抗爆性能.当比例爆距小于0.4095mkg^-3,GFRP筋混凝土梁用C50及以上混凝土能有效减少混凝土震塌与剥落.研究表明,GRCBs比SRCBs具有更高的抗爆性能.

Experimental study and numerical simulation of explosion resistance of GFRP reinforced concrete beams

Glass fiber reinforced polymer(GFRP)bars have the advantages of corrosion resistance and high tensile bearing capacity.It can be used as longitudinal reinforcement of concrete protective structures instead of steel reinforcement.In order to clarify the anti-explosion performance of GFRP reinforced concrete beam(GRCBs),the explosion experiment,static bending experiment and numerical simulation analysis of GFRP reinforced concrete beam and reinforced concrete beam(SRCBs)are carried out.The results show that,in the four-point bending static experiment,the bearing capacity of GRCBs designed with the same equivalent stiffness is 5.5 times that of SRCBs under the working condition of 3 kg-0.65 m explosion loading.With the action of near explosion(proportional detonation distance is less than 0.5159 m kg^-3),because the GFRP bars are in the elastic stage,the failure forms are mainly crack,flake and collapse of concrete.According to numerical simulation,the increase of the stiffness of FRP bars can reduce the mid-span displacement of GRCBs.The ratio of the maximum mid-span displacement reduction rate to EA ratio is 0.1,which can reduce the crack and damage of GRCBs and enhance the anti-explosion performance of GRCBs.When the proportional detonation distance is less than 0.4095 m kg^-3,C50 and above concrete used in GFRP reinforced concrete beams can effectively reduce concrete collapse and spall.The results show that GRCBs have higher blast resistance than SRCBs.