型钢再生混凝土黏结滑移推出试验及黏结强度分析

为研究型钢与再生混凝土界面之间的黏结滑移性能，以再生粗骨料取代率、型钢与再生混凝土的黏结部位、型钢保护层厚度、横向配箍率、再生骨料母料强度和再生骨料粒径等为变化参数，设计了22个型钢再生混凝土试件，采用位移控制的加载方法进行推出试验。通过观察试件的受力破坏过程，分析型钢与再生混凝土界面黏结失效机理，获取其裂缝发展形态、应力分布情况、加载端和自由端滑移分布规律；分析不同参数对型钢再生混凝土黏结滑移性能的影响规律。研究结果表明：型钢不同黏结部位与混凝土的黏结应力不同，翼缘内侧黏结应力最高，翼缘外侧次之，腹板黏结应力最小；黏结应力沿型钢埋置长度方向呈指数分布；再生骨料的母料混凝土使用时间越长，用其生产的骨料配置的同条件的混凝土强度越低；再生混凝土骨料粒径越小，再生混凝土与型钢的极限黏结强度越小。

Push-out test on interface bond slip behavior and analysis on bond strength between steel and recycled coarse aggregate concrete

In order to study the bond-slip performances between steel and recycled concrete, Twenty-two specimens, with different recycled aggregates replacement ratios, steel and concrete bonding locations, cover thickness, ratios of the transverse hoops, strength of different recycled aggregates mother material and recycled aggregates grain size, were designed and displacement control push-out testing was conducted. Through the experiments, specimens’ failure process were observed; steel reinforced concrete bonding failure mechanism was revealed; crack form, stress distribution, loading end and free end slip distributions were obtained; the law of steel recycled concrete bond-slip properties influenced by all the parameters was analyzed. The results show that: the steel and concrete bond strength at different parts is different. the inner side of the flange bond strength is higher, while the outer side of the flange bond strength is smaller, the web bond strength is the smallest; bond strain along anchorage length follows exponential distribution; if the master batch of recycled aggregate concrete’s used time is longer, the strength of concrete with this kind of master batch aggregate is lower; recycled aggregate size is smaller, the ultimate bond strength of recycled concrete and steel is smaller.