doi:10.16186/j.cnki.1673-9787.2022080020

Received:2022/08/11

Revised:2022/11/28

Published:2024/01/25

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

DU Guofeng, CAO Xuan, XIE Xiangdong, ZHANG Jicheng

School of Urban Construction，Yangtze University，Jingzhou 434023，Hubei，China

Abstract: Objective In order to study the bond-slip performance between high-strength steel tube and Ultra-high 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.

Key words:high-strength steel tube;Ultra-high Performance Concrete;push-out test;bond-slip;bond strength