工字型钢超高性能混凝土梁受弯性能试验研究  

Experimental Study on Flexural Behavior of I-section Steel Ultra High Performance Concrete(UHPC)Beams

作　　者：卜良桃[1] 唐长久 BU Liangtao;TANG Changjiu(College of Civil Engineering,Hunan University,Changsha,Hunan 410082,China)

机构地区：[1]湖南大学土木工程学院,湖南长沙410082

出　　处：《公路工程》2021年第4期1-7,65,共8页Highway Engineering

基　　金：国家自然科学基金项目(51278187)。

摘　　要：为研究工字型钢超高性能混凝土(UHPC)梁的受弯性能,设计了6根长3500 mm工字型钢UHPC梁的跨中单点静载试验,设置UHPC的强度等级和型钢腹板厚度两个变量,分析试验梁的裂缝发展情况、跨中截面荷载-挠度曲线和应变沿截面高度分布曲线。试验结果表明:工字型钢UHPC梁具有超高受弯承载力与抗裂性,开裂荷载达到其极限荷载的56.4%~62.6%;提高UHPC强度等级和增加型钢腹板厚度可以增强工字型钢UHPC梁的刚度、延性和抗裂性,能增加试件的开裂荷载、屈服荷载与极限荷载;工字型钢UHPC梁达到极限破坏时主裂缝两侧UHPC通过钢纤维继续保持黏结,UHPC的抗拉强度提高了工字型钢UHPC梁的极限受弯承载力。推导出工字型钢UHPC梁考虑UHPC抗拉强度的受弯极限承载力计算公式,为该受弯构件在实际工程的应用提供试验依据。In order to study the bending behavior of I-section steel ultra high performance concrete(UHPC)beams,six I-section steel UHPC beams with the length of 3500 mm were designed for mid-span single-point static load test.There were two variables of UHPC strength grade and section steel web thickness set in this test,and the crack development of the test beam,the load-deflection curve of the mid-section and the height distribution curve of the strain along the section were analyzed.It was found that the I-section steel UHPC beam has ultra-high bending capacity and crack resistance,whose cracking load reaches 56.4%~62.6%of ultimate load;the stiffness,ductility and crack resistance of I-section steel UHPC beam can be enhanced by increasing the strength grade of UHPC and the thickness of section steel webs,which is also beneficial to increasing the cracking load,yield load and ultimate load of specimens.When the I-section steel UHPC beam reaches the ultimate failure,the UHPC on both sides of the main crack continues to bond through steel fiber,and the tensile strength of UHPC improves the ultimate bending capacity of the I-section steel UHPC beam.The formula for calculating the ultimate bearing capacity of the UHPC beam considering the UHPC tensile strength was derived,which provided experimental basis for the application of the structure in practical engineering.

关 键 词：超高性能混凝土 工字型钢 受弯性能 腹板厚度 

分 类 号：TU37[建筑科学—结构工程]