Condition and Durability Evaluation of Reinforced-Concrete Bridge Girders in the Surabaya Container Terminal Environment

Abstract

An access bridge at PT Terminal Petikemas Surabaya has operated since 1992 in a chloride-bearing marine environment and carries repetitive heavy operational vehicles. The reinforced-concrete girders were repaired by epoxy injection and strengthened with carbon-fibre-reinforced polymer between 2010 and 2014; however, cracks were identified again in 2021. This study evaluates the existing condition and durability of the girders by integrating repair-history review, visual inspection and crack mapping, concrete core testing, rebound-hammer testing, reinforcement detection, half-cell potential measurements, and chloride-based service-life analysis. Seven 93-mm-diameter cores produced equivalent standard-cylinder compressive strengths of 51.33–59.31 MPa, with a mean of 54.74 MPa and a coefficient of variation of 5.20%, while the average rebound-hammer estimate was 62.02 MPa. The average concrete cover of the girders was 60 mm. Half-cell potentials were generally more positive than −200 mV, indicating a low probability of active corrosion at the time of testing. The apparent chloride diffusion coefficient for the girders was 1.77 × 10−8 cm²/s, yielding a nominal corrosion-initiation time of 21.12 years under the adopted assumptions. Although the measured core strengths exceeded the conservative 50 MPa value adopted in structural checks, recurrent cracking remained evident. The integrated diagnosis therefore indicates that the observed cracking is more plausibly associated with continuing structural demand, previously active cracks, reduced cracked-section stiffness, or uncertain CFRP bond effectiveness than with generalised low concrete strength or widespread active corrosion. A risk-based maintenance framework is proposed, prioritising quantitative crack monitoring, verification of CFRP bond condition, repeated electrochemical assessment, and control of heavy vehicle operations.