重复推出下钢管再生混凝土黏结-滑移性能影响因素

Influencing Factors on Bond-Slip Performance of Recycled Aggregate Concrete Filled Steel Tubes under Repeated Push-out

为研究钢管再生混凝土(RACFST)在原生混凝土强度等级、锈蚀率和膨胀剂掺量影响下的黏结-滑移性能,开展了重复推出试验,分析了荷载-滑移曲线、耗能能力、应变分布和各因素对RACFST峰值荷载的影响,并建立了黏结强度计算模型.结果表明:混凝土奇数次推出时的耗能能力和钢管表面应变分布大于偶数次推出时;峰值荷载随着原生混凝土强度的提高而增大,随着锈蚀率和膨胀剂掺量的提高分别呈先增大后减小、先减小后增大趋势;基于Rational函数和Expdec1函数建立的黏结强度计算模型具有较高可靠性.

In order to investigate the bond-slip performance of recycled aggregate concrete filled steel tubes(RACFST)in terms of the parent concrete strength grade,corrosion rate and expansion agent,the repeated push-out test of RACFST was carried out.The load-slip curve,energy consumption capacity,strain distribution and the influence of above three factors on the peak load of RACFST were studied.A computational model for bond strength was developed.The results show that the energy consumption capacity and strain distribution of odd times of the push-out test are greater than those of even times.The peak load increases with the strength of the parent concrete.With the increase of corrosion rate and expander content,the peak load increases first and then decreases,and decreases first and then increases.The bond strength calculation models based on the Rational and Expdec1 functions are highly reliable.