Experimental study on the bond-slip behavior and stress transfer mechanism between shaped steel and high-performance fiber-reinforced concrete

Abstract

In light of the weak bond strength between the two materials in steel reinforced concrete (SRC) and the brittleness of high-strength concrete, the use of high-performance fiber-reinforced concrete (HPFRC) was proposed with the addition of cellulose fiber and rice husk ash (RHA) in high-strength concrete. The purpose of this study is to investigate the bond behavior of shaped steel embedded in HPFRCs. Thirteen push-out test specimens of steel high-performance fiber-reinforced concrete (SHPFRC) were cast. The test parameters considered in this study were the HPFRC strength, cover thickness, embedment length, and stirrup ratio. The experimental process and failure modes were analyzed, and the influence of various test parameters on the average bond strength was studied. The average effective bond stress was introduced to study the whole process of bond failure and the stress transfer mechanism. Then, a method for calculating the bond stress was established. The results showed that the failure modes of the specimens were classified into bond splitting failure, bond anchorage failure, and mixing failure. The parameters have various effects on the average bond strength. The introduction of the average effective bond stress reflected the transfer mechanism of bond stress at the interface. The largest component of bond stress was chemical adhesion, and mechanical interaction was the smallest.