钢筋-超高性能混凝土黏结性能的非线性有限元分析

Nonlinear Finite Element Analysis of Bond Property Between Reinforcing Rebar and Ultra-High Performance Concrete

针对配筋-超高性能混凝土(UHPC)构件间的黏结性能问题,采用ABAQUS非线性弹簧单元对不同保护层厚度、黏结长度和钢筋直径的配筋UHPC黏结-滑移关系进行了仿真分析,并探讨了不同参数对UHPC黏结性能的影响。结果表明:配筋UHPC的界面极限黏结应力随着UHPC保护层厚度的增加而提高,而随着配筋直径及黏结长度的增加而降低。保护层厚度从单倍钢筋直径增至1.5~2.0倍钢筋直径时,其极限应力增加17.3%~33.3%;钢筋直径从8 mm增加至12 mm和16 mm时,其极限应力分别降低16.5%和28.8%;黏结长度从4倍钢筋直径增加至6~8倍钢筋直径时,其极限黏结应力降幅为14.7%~25.3%。经有限元分析获得的极限黏结应力与文献计算结果符合度较好,误差均值约为2%。

In view of the bond property of reinforced ultra-high performance concrete(UHPC)member,and by using the nonlinear spring element of ABAQUS,a simulation and analysis have been made of the bond-slip relationship of reinforced UHPC with different cover heights,bond lengths and rebar diameters,followed by a further inquiry into the influences on the bond properties.The results show that the ultimate interfacial bonding stress of reinforced UHPC increases positively with the increase of UHPC protective layer thickness,while decreases negatively with the increase of reinforcement diameter and bonding length.The thickness of the protective layer increases from a single steel bar diameter to 1.5~2.0 times the steel bar diameter,with the ultimate stress increasing by 17.3%~33.3%.When the diameter of reinforcement increases from 8 mm to 12 mm and 16 mm,the ultimate stress decreases by 16.5%and 28.8%respectively.Furthermore,with the bond length increasing from 4 times of the rebar diameter to 6~8 times the value,the ultimate interfacial bonding stress decreases by 14.7%~25.3%accordingly.The ultimate bond stress obtained by finite element analysis is in agreement with the computational calculation results,with a relatively lower error of about 2%.