Anti-corrosion performance of a novel ECC-GFRP spiral-confined RC column

Abstract

The primary strategy for enhancing the durability of reinforced concrete (RC) structures is to inhibit the spread of corrosive agents and employ corrosion-resistant materials. Aligning with this approach, this study experimentally evaluated a novel reinforced protective layer for RC columns, which incorporates spiral glass fiber-reinforced polymer (GFRP) within engineered cementitious composite (ECC) material. This design aims to leverage the corrosion-resistant properties of these materials to improve the overall durability of RC structures. A total of 18 ECC-GFRP spiral-confined RC columns were constructed, varying in rebar corrosion rate, ECC thickness, and type of protective layer. To accelerate rebar corrosion, an electrochemical technique was applied, facilitating a comparative analysis of corrosion resistance. These ECC-GFRP spiral-confined RC columns exhibited superior crack control, suggesting a potential for enhanced structural corrosion resistance. The results indicate that the ECC-GFRP spiral cover effectively lowers the rate of steel bar corrosion, while increasing the structure’s load-bearing capacity and ductility, particularly in harsh conditions. Moreover, the ECC and GFRP spiral confinement effectively mitigates the uneven lateral strain distribution caused by rebar buckling. With increased ECC thickness, the local stress concentration in the ECC layer diminishes, and actual corrosion rates decrease, thereby improving structural deformation capability. Finally, the study presents an analytical formula, consistent with design codes, to predict the load-bearing capacity of ECC-GFRP spiral-confined columns under varying corrosion rates, which aligns well with the experimental findings.

Keywords

• Durability of RC columns
• GFRP spiral
• Engineered cementitious composites (ECC)
• Compressive test
• Rebar corrosion
• Confinement