Effectiveness of a dual-functional intervention method on the durability of reinforced concrete beams in marine environment

•Development of a dual-functional intervention method for reinforced concrete beams.•Experimental programme on simply supported beams repaired by ICCP-SS method.•Analysis on the structural responses of simply supported beams with C-FRCM strengthening.•Comparison of test results with existing design methods.•Recommendation of changes on the design methods for cross-section capacity prediction.