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

Zongshan Wang,Jun Yang,Weicheng Wang,Jianting Zhou,Lei Chen

doi:10.1155/2020/4015063

Zongshan Wang, Jun Yang + Show 3 more

Open Access

https://doi.org/10.1155/2020/4015063

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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.

Highlights

E conventional retrofitting techniques found in the literature are the application of steel profiles at the arch intrados, the use of reinforced concrete hoods, and the introduction of a reinforced concrete layer at the arch intrados or extrados
To analyze the failure mode, strain distribution, and bearing capacity of a plain concrete (PLC) arch bridge reinforced with ultra-high performance concrete (UHPC) arch circle, 15 segment models, of which 2 were not reinforced, 4 were reinforced with NC, and 9 were reinforced with UHPC, were designed for eccentric compression experiment
Considering the complexity of arch fabrication, the failure mode, strain distribution, and bearing capacity of a PLC arch bridge reinforced with UHPC arch circle were analyzed by segment models

Summary

Experimental Program

Considering the complexity of arch fabrication, the failure mode, strain distribution, and bearing capacity of a PLC arch bridge reinforced with UHPC arch circle were analyzed by segment models. (3) When these 13 PLC columns were strengthened, four were strengthened by NC with a 70 mm reinforcement layer, recorded as group N, eight were strengthened by UHPC with a 35 mm reinforcement layer, and the last one was strengthened by UHPC with a 70 mm reinforcement layer, recorded as group U. ree HRB335 bars with a diameter of 12 mm were set in the middle of the reinforcement layer, and a concrete segment of 100 mm long at both ends of each test piece was poured together with the reinforcement layer concrete to enhance the local performance and maintain the same height level with group P. Specimens were named as type (P, N, and U) followed by

C Longitudinal section after reinforcement

Results and Discussion

Conclusions