钢筋与活性粉末混凝土黏结性能的梁式试验研究

Beam Test of Bond Behavior Between Steel Bars and Reactive Powder Concrete

采用梁式黏结试验研究活性粉末混凝土与钢筋的黏结性能。研究表明:活性粉末混凝土梁式试验中的黏结破坏呈现钢筋拔出破坏、钢筋拔出与混凝土劈裂破坏共同发生等两种破坏形式。活性粉末混凝土与钢筋的极限黏结强度及所对应的滑移值分别约为普通混凝土的2倍左右。通过试验给出黏结应力-滑移曲线,曲线分为微滑移段、滑移段、滑移加速段和下降段等4个阶段。分析表明:保护层厚度及埋长对钢筋黏结锚固特征值有一定的影响。本文通过试验与分析提出用相对保护层厚度及相对埋长表示各阶段黏结锚固特征值的拟合计算公式,为工程设计提供参考。

Bond proprieties of reinforced reactive powder concrete beams were studied. It is concluded as fol- lows： there are two modes of bond failure in beam tests of reactive powder concrete; one is steel pullout and the other is steel pullout together with concrete splitting~ the ultimate bond strength and its corresponding slip values are about twice of normal concrete; the bond stress-slip curve of reactive powder concrete can be divided into four sections, i. e. , the sections of micro-slip, slip, slip speed-up and descending; the corresponding char- acteristic values are affected to some extent by the thickness of concrete cover and bond length of embedment. The empirical formula for characteristic values related to the relative thickness of concrete cover and relative bond length of embedment fit the test results, which can provide reference to engineering design.