Energy dissipation and damage on the interface of steel and steel fiber‐reinforced concrete composite column

Abstract

To address the problems faced with steel-reinforced concrete (SRC) in construction, such as positional conflicts between steel and steel bars or difficulty in pouring concrete, a novel "Steel and Steel Fiber-Reinforced Concrete" (SSFRC) composite structure was proposed. Push-out tests of 34 SSFRC composite columns were carried out in this paper to study the interfacial bond performance from the perspective of energy dissipation. Based on loading-displacement (P-D) curves, the interfacial energy dissipation (W b ) and energy dissipation factor (λ) were introduced, and the influence of embedded length (L e ), steel fiber volume rate (ρ sf ), thickness of concrete cover (C ss ), and section type on W b and λ were analyzed. Test results indicated that circular column is better than square column in terms of W b and λ. The increase of L e , C ss , or ρ sf is beneficial to the improvement of W b , and λ is positively correlated with ρ sf and C ss but negatively correlated with L e . Additionally, the interfacial damage (D a ) was defined by the relationship between elastic deformation energy (W a ) and W b . It can be concluded that the ascent of L e and C ss can effectively delay the appearance of D a and inhibit the development of D a , respectively, and D a develops slowly with the increase of ρ sf at the later loading stage.