Experimental investigation of fatigue behavior of UHPFRC – RC composite deck slabs subjected to moving wheel loading

Abstract

UHPFRC has been increasingly used as a bridge deck overlay material. Since bridge decks are exposed to severe mechanical action and harsh environmental conditions, the application of UHPFRC to bridge decks is an effective and wise utilization of UHPFRC’s excellent properties such as high strength and low permeability. This paper presents the result of a full-scale fatigue test of a reinforced concrete (RC) deck slab overlaid with UHPFRC (UHPFRC – RC composite deck slab) using a moving wheel load. The fatigue behavior of the UHPFRC – RC composite deck slab was analyzed using measurement data from the experimental test and discussed. The failure mode of the UHPFRC – RC composite deck slab was punching shear accompanied by near-interface concrete cracking and double curvature bending of the UHPFRC layer. The fatigue life of the UHPFRC – RC composite deck slab was estimated using an existing S-N relation of RC deck slabs subjected to moving wheel loads and a 30 mm thick UHPFRC overlay was found to increase the fatigue life of RC deck slabs by about five times.