Assessment of reinforcement materials and a decision framework for chloride-exposed concrete structures

The durability of reinforced concrete (RC) in chloride-laden environments largely depends on the corrosion resistance of embedded reinforcement and its bond with cover concrete. This study evaluated seven reinforcement types: uncoated (as-received and sandblasted TMT), coated (fusion-bonded epoxy-coated (FBEC), cement-polymer composite coated (CPCC), and dual zinc-galvanized epoxy-coated (DZGEC)), and alloyed (corrosion-resistant steel (CRS) and stainless steel (SS)), through electrochemical testing, salt-spray exposure, coating-abrasion, and pull-out bond tests. Electrochemical testing was conducted for both interface characterization and chloride threshold estimation under chloride ponding. Coated rebars with simulated damage were also examined to assess handling durability. Results showed up to 22 % bond-strength reduction in FBEC-coated rebar compared with uncoated steel, while CPCC exhibited the least loss owing to its cementitious sealer layer. FBEC demonstrated the highest abrasion resistance, followed by DZGEC and CPCC. SS and DZGEC displayed around 104 % and 84 % higher chloride-threshold values, respectively, relative to sandblasted TMT, corresponding to nearly five times and three times longer corrosion-initiation periods. An Optimum Reinforcement Decision-Making (ORDM) framework was developed to integrate corrosion resistance, bond strength, weathering resistance, and material cost. The framework uses expert-assigned weightages, obtained from 165 professional responses, to support the rational selection of reinforcement materials for RC structures exposed to chloride environments. • Experimental evaluation of coated and alloyed reinforcements under chloride-rich conditions. • Investigation of coating degradation and its influence on corrosion initiation. • Development of an optimum reinforcement decision-making (ORDM) framework. • Integration of expert opinion and performance indicators for material selection.