STRENGTH AND SERVICEABILITY ASSESSMENT OF AN EXISTING REINFORCED CONCRETE DECK ON A STEEL TRUSS BRIDGE

Abstract

The deck is one of the bridge components that receives traffic loads directly and is therefore vulnerable to repeated loading and environmental deterioration. This paper evaluates the structural performance of the existing cast-in-place reinforced concrete deck of the Citarum Baru steel truss bridge in West Java, Indonesia. The bridge has a 60 m main span, while the deck was represented by a finite-element shell model in SAP2000 using geometry and material properties obtained from project documents and as-built drawings. Loading followed SNI 1725:2016 and included self-weight, asphalt, water ponding, lane load D, and the 500 kN truck load T. The assessment considered flexural demand, shear demand, the demand-capacity ratio, and service deflection. The maximum factored bending moment was 481.34 kN·m and the reported design flexural capacity was 679.27 kN·m, giving a demand-capacity ratio of 0.708. The maximum shear demand was 662.819 kN, and the shear check was reported to satisfy the required capacity. In contrast, the service deflection reached 36.8 mm, which exceeded the allowable limit of 16.67 mm. The results show that the deck still satisfies the reported strength checks but does not satisfy the deflection requirement. For an existing bridge with visible cracking, wear, and local deck damage, this difference is important because a satisfactory strength ratio alone does not demonstrate acceptable service performance.