高强钢管超高性能混凝土界面黏结滑移性能试验

Test of interfacial bond-slip behavior of Ultra-high Performance Concrete filled high-strength steel tube

目的为了研究高强钢管超高性能混凝土的黏结滑移性能,方法考虑径厚比、长径比和钢纤维掺量3个参数的影响,设计并制作15根构件进行试验研究,通过推出试验,得到轴向荷载与加载端位移的荷载-位移曲线,以及高强钢管与超高性能混凝土之间的黏结强度,根据试验结果,对影响黏结强度的参数进行定性定量分析。结果结果表明:随着高强钢管长径比和径厚比的增加,黏结强度减小;随着钢纤维掺量增加,试件黏结强度先增加后减小,即当钢纤维掺量从1%增加到2%时,黏结强度增加,但当钢纤维掺量从2%增加到3%时,黏结强度反而降低;试件荷载-滑移曲线表现为两种形式,一是有明显的峰值点,峰值点后曲线急速下降(部分出现尾部上升的现象),二是曲线无明显峰值点,拐点后曲线持续缓慢增长。高强钢管超高性能混凝土的黏结破坏分为黏结阶段、滑动阶段和抗摩擦阶段。结论以长径比、径厚比、含钢率和套箍系数为参数,结合试验数据并对其进行回归分析,得到适用于高强钢管超高性能混凝土黏结强度的计算模型,并将计算结果与试验结果进行对比,计算值与试验值吻合较好,可为实际工程提供一定参考。

Objective In order to study the bond-slip performance between high-strength steel tube and Ultrahigh Performance Concrete,Methods the influence of three parameters including the diameter-thickness ratio,length-diameter ratio,and steel fiber dosage is considered.Fifteen specimens are designed and manufactured for experimental research.By conducting experiments,the load-displacement curves of axial load and displacement at the loading end are obtained,as well as the bond strength between high-strength steel tube and ultra-high performance concrete.Based on the experimental results,a qualitative and quantitative analysis is performed on the parameters affecting bond strength.Results The results show that with the increase of length-diameter ratio and diameter-thickness ratio of high-strength steel tube,the bond strength decreases.With the increase of steel fiber dosage,the bond strength of the specimens first increases and then decreases.Specifically,when the steel fiber dosage increases from 1%to 2%,the bond strength increases,but when the steel fiber dosage increases from 2%to 3%,the bond strength decreases.The load-slip curve of the specimens exhibits two types:one with a distinct peak point and a rapid drop in the curve after the peak point(with some cases showing a slight increase in the tail),and the other with a slow and continuous increase in the curve after the inflection point.The bond failure of high-strength steel tube Ultra-high Performance Concrete can be divided into the bonding stage,sliding stage,and anti-friction stage.Conclusion By considering the length-diameter ratio,diameter-thickness ratio,steel content,and hoop coefficient as parameters,and combining the experimental data for regression analysis,a calculation model for bond strength applicable to high-strength steel tube Ultra-high Performance Concrete is obtained.The calculated results are compared with the experimental results,showing good agreement,which can provide a reference for actual engineering.