Experiment on the Segment Model of a Plain Concrete Arch Bridge Reinforced with UHPC Composite Arch Circle

Abstract

This research aims to investigate the efficiency of strengthening of plain concrete (PLC) arches using UHPC. Thirteen segment arch models reinforced using normal concrete (NC, group N) or ultra-high performance concrete (UHPC, group U) were tested in this study. The failure mode, strain distribution, and calculation of bearing capacity of PLC arch bridges reinforced with UHPC arch circle were analyzed. The experimental results showed that the technology of chiseling and planting bars could provide sufficient bond strength on the interface between the UHPC reinforcement layer and NC substrate. Both groups showed one or two failure modes of the concrete crushing of the original structure and the interface failure. However, no cracks appeared in the UHPC reinforcement layer, indicating that there was still large bearing potential. The strain distribution of the whole section in group N was consistent with the plane section assumption. But, this phenomenon was not observed in group U since the strain of the reinforcement layer was ahead (R-side loading) or behind (L-side loading) that of original structures. A simplified calculation formula was used for calculating the bearing capacity of group U. It was accurate for specimens loaded on the L-side, and an enhancement coefficient of 0.15 should be considered for R-side loading specimens.