型钢高性能纤维混凝土粘结滑移性能试验研究

为研究型钢与高性能纤维混凝土之间的粘结滑移性能，以高性能纤维混凝土强度、保护层厚度以及型钢锚固长度为变化参数，设计10个型钢高性能纤维混凝土试件，进而对其进行推出试验，观察试件的破坏过程和裂缝发展形态，获取试件的荷载-滑移曲线。基于试验结果，探讨了各设计参数对特征粘结强度的影响规律，并建立了特征粘结强度的计算公式。对有效粘结应力计算公式进行推导，得到有效粘结应力-滑移分布曲线，并对其进行全过程分析。结果表明:适当增加型钢保护层厚度和混凝土强度，能有效提高型钢高性能纤维混凝土的特征粘结强度；特征粘结强度计算值与试验值吻合较好，表明该文提出的计算公式具有较高的精度；有效粘结应力能够反映型钢与高性能纤维混凝土界面间粘结应力的发展变化过程，并得到粘结应力各组份之间的比例关系。研究成果可为型钢高性能纤维混凝土相关计算理论提供试验依据。

EXPERIMENTAL STUDY ON BOND-SLIP BEHAVIOR BETWEEN ENCASED STEEL AND HIGH-PERFORMANCE-FIBER CONCRETE

Ten push-out experimental specimens were cast and tested to study the interfacial bond-slip behavior of section steel and high-performance fiber concrete (HPFC). The main parameters investigated were strength grade, concrete cover thickness and embedded length. The failure process and load-slip (P-S) curves were obtained. The influence regularities of design parameters on the characteristic bond strength were studied, and the formulae of characteristic bond strength were established. The effective bond stress was introduced and deduced. Through the analysis of the whole process of the effective bond stress slip curve, the development of bond stress was obtained. The results show that : the characteristics bond strength were increased by the increase of the concrete cover thickness and the concrete strength; the calculated value of the characteristics bond strength appeared were similar to that of the test values; the effective bond stress reflected the development and transformation of bond stress at the interface between section steel and high-performance-fiber-concrete; the proportional relationship among the components of the bonding force was derived by process analysis. The research provides an experimental support for analyzing the mechanical behaviors of steel reinforced high-performance-fiber-concrete.