Work

Effect of bond performance on flexural crack width of SCBSB concrete beam

Year: 2026

Type: article

Abstract: Stainless steel-clad bimetallic steel bars (SCBSB) are an attractive choice for durable reinforced concrete (RC) structures in aggressive environments, where controlling crack width is critical to preventing chloride ingress and exploiting the cladding’s corrosion resistance. However, at the beam component level, the bond behavior of SCBSB differs from that of conventional and solid stainless steel reinforcement, and how this distinct bond performance influences crack development and serviceability remains poorly understood. To clarify the bond-dependent cracking mechanisms, eleven beams with varied reinforcement types, concrete strengths, and reinforcement ratios were tested under four-point bending, and their failure modes, load capacity, strain distribution, and crack evolution were systematically examined. The results show that both the yield and ultimate loads increase with higher reinforcement ratios and concrete strength grades. This distributed crack pattern, attributed to the distinct bond characteristics of the clad reinforcement, produces narrower cracks that restrict chloride ingress and better preserve the protective function of the stainless steel cladding. A bond–slip constitutive model calibrated from pull‑out tests was incorporated into a nonlinear finite element model, which accurately predicted the load–deflection response, crack width evolution, and failure modes. Parametric analysis confirmed that bond stiffness strongly governs crack width under high service loads, and the validated model provides a reliable tool for optimizing crack-control design of RC beams with SCBSB.

Source: Engineering Structures

DOI: 10.1016/j.engstruct.2026.123809