|Table of Contents|

Flexural behavior tests of fullscale concrete T girders withsteelUHPFRC composite strengthening

长安大学学报（自然科学版）[ISSN:1006-6977/CN:61-1281/TN]

Issue:
2018年06期
Page:
117-126
Research Field:
桥梁与隧道工程
Publishing date:

Info

Title:
Flexural behavior tests of fullscale concrete T girders withsteelUHPFRC composite strengthening
Author(s):
WANG Chunsheng1;  WANG Shichao1;  ZHAO Tao2;  DUAN Lan1;  WANG Qian1
(1. Shaanxi Provincial Major Laboratory for Highway Bridge and Tunnel, Changan University, Xian 710064,Shaanxi, China; 2. Ningxia Highway Engineering Co., Ltd., Yinchuan 750002, Ningxia, China)
Keywords:
bridge engineering;  steelconcrete composite strengthening girder;  steelUHPFRC composite strengthening girder;  flexural behavior;  fullscale test
PACS:
-
DOI:
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Abstract:
To recover the flexural behavior of the superstructure in concrete Tgirder bridges after damage under extreme loads such as earthquake, explosion, and fire, the steelUHPFRC composite reinforcement method, which improves the steelconcrete composite reinforcement technology by using the excellent flexural performance of the UHPFRC material, was proposed. The experimental research was conducted on damaged fullscale concrete Tgirders. The flexural behavior under the normal performance stage and the bending failure mode at the bearing capacity limit state of both steelconcrete composite strengthened Tgirder and steelUHPFRC composite strengthened Tgirder were experimentally analyzed by bending tests. Based on the bending failure mode of fullscale Tgirders, the bending capacity calculation diagram and simplified formula of steelUHPFRC composite strengthened concrete Tgirders were established. The results show that plastic bending failure of the steelUHPFRC composite strengthened test girders. The crosssection deformation of the girders conforms to the flat section assumption. The longitudinal relative slip between the reinforcement and the original structure is less than 0.35 mm. Compared to the unstrengthened girders, the strengthened test girders demonstrate an overall improvement in the working performance. It is observed that the ultimate flexural capacity of the girder increases by 71% after strengthening with steelconcrete composite. Under the condition that the weight of the reinforcing material is reduced by 50%, the ultimate flexural capacity of girder strengthened with steelUHPFRC composite can be increased by 30%. Further, the flexural behavior of the steelUHPFRC composite reinforced concrete Tgirder is similar to that of the steelconcrete composite reinforced concrete Tgirder under the normal performance stage. Therefore, the steelUHPFRC composite reinforcement can improve or restore the flexural capacity of the concrete Tgirder and reduce the weight of the reinforcement, which contributes to the selfweight of the structure. The values of simplified bending capacity obtained from the theoretical analysis and the experimental results are compared for both the steelconcrete composite reinforced girder and steelUHPFRC composite reinforced girder, and the ratios of the values for the girders are found to be 0.97 and 0.95, respectively. Thus, the simplified calculation formula is reliable and can be used in the design calculations of composite reinforced concrete Tgirder bridges. 4 tabs, 19 figs, 21 refs.

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Last Update: 2018-12-18