受压区局部约束塑钢纤维轻骨料混凝土梁的抗弯性能  

Flexural Behavior of Plastic Steel Fiber Reinforced Lightweight Aggregate Concrete Beams Confined Locally in Compression Zone

作　　者：牛建刚 许文明 梁剑 NIU Jiangang;XU Wenming;LIANG Jian(School of Civil Engineering,Inner Mongolia University of Science and Technology,Baotou 014000,China;School of Civil Engineering,Guangxi University,Nanning 530000,China)

机构地区：[1]内蒙古科技大学土木工程学院,包头014000 [2]广西大学土木工程学院,南宁530000

出　　处：《材料导报》2021年第8期56-63,共8页Materials Reports

基　　金：国家自然科学基金(51368042);内蒙古自治区青年科技英才支持计划(NJYT-18-A06)。

摘　　要：为提高塑钢纤维轻骨料混凝土梁的受弯性能,采用矩形箍约束局部受压区的方式,设计了六根受压区增强塑钢纤维轻骨料混凝土梁,分析了纵筋配筋率和混凝土强度对塑钢纤维轻骨料混凝土梁受弯力学性能的影响,并对其进行有限元分析。结果表明:采用箍筋约束受压区混凝土后,局部受压区极限压应变增大,试件的承载力和延性有显著提高;随着配筋率增加,试件的承载力有明显提高,且高配筋率梁的超筋破坏现象得到明显改善;随着约束区混凝土强度的增大,梁的承载力变大,而延性降低。有限元分析结果表明,在受压区局部配置箍筋约束后,受压区混凝土极限压应力变大,极大地改善了梁跨中受压区的应力集中现象,从而抑制了梁受压区边缘混凝土的压碎破坏,提高了梁的承载力和延性。In order to improve the flexural performance of the beam,six reinforced plastic steel fiber reinforced lightweight aggregate concrete beams were designed by using rectangular hoops to restrain the local compression area.The influence of the longitudinal reinforcement ratio and the concrete strength on the flexural mechanical properties of the beam was analyzed and the finite element analysis was carried out.The results show that when stirrups are used to restrain the concrete in the compression zone,the ultimate compressive strain in the local compression zone increases,and the bearing capacity and ductility of the specimen increase significantly;with the increase of reinforcement ratio,the bearing capacity of the specimen increases significantly,and the over reinforcement failure of the beam with high reinforcement ratio is improved obviously;with the increase of concrete strength in the restraint zone,the bearing capacity of the beam increases,while the ductility decreases.The results of finite element analysis show that the ultimate compressive stress of the concrete in the compression area becomes larger after the stirrup is placed locally in the compression area,which greatly improves the stress concentration in the compression area in the middle of the beam span,thus inhibiting the crushing failure of the concrete at the edge of the compression area of the beam,and improving the bearing capacity and ductility of the beam.

关 键 词：塑钢纤维 轻骨料混凝土 承载力 延性 

分 类 号：TU528.2[建筑科学—建筑技术科学]