Full-scale experimental study on shear behavior of multiple-keyed epoxy joints in precast concrete segmental bridges

Zhang, Yongping; Zhang, Zhihao; Hu, Fangjian; Du, Xiaoyong; Lu, Yuanchun; Zhu, Jiong-Yi

doi:10.1016/j.istruc.2022.09.025

Cited by 10 publications

(3 citation statements)

References 21 publications

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“…The results indicated that the application of epoxy adhesive to dry joints could enhance shear-carrying capacities. Zhang et al [ 18 ] investigated the shear performance of full-scale multiple-key epoxy joints under direct shear. It was found that an increase in epoxy adhesive thickness resulted in smoother shear stress transfer, as well as more uniform stress distribution on the shear surface.…”

Section: Introductionmentioning

confidence: 99%

Shear Performance of Epoxy Joints in a Precast Bridge Deck Considering Constraint Effects

Zhang

Wang

et al. 2023

Polymers

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The joint form plays a vital role in the rapid assembly of precast bridge decks for steel–concrete composite bridges. Existing research primarily focuses on studying the shear performance of joints through direct shear tests, which is insufficient to fully reflect the mechanical behavior of joints under the constraint of prefabricated bridge deck panels during actual vehicular traffic. Considering situations such as vehicle loads and external forces acting on precast bridge decks, this study investigates the shear performance of epoxy joints under constraint through an improved shear test. The influence of constraint force, shear key details and interface defects on the shear performance of epoxy joints is investigated. The results reveal that the shear test method employed in this study can realistically reflect the shear performance of epoxy joints in precast bridge decks. Both active and passive constrained epoxy joint specimens exhibited no interface cracks, and their failure modes were identified as shear failure between mid-span supports. Compared with passive constraint, the shear-bearing capacity of epoxy joint specimens under active constraint was increased by 86.1~130.6%. Among the epoxy joint specimens with depth–height ratios of 15/110, 25/110, 35/110 and 45/110, the joint with a depth of 35 mm demonstrated the highest shear strength. Furthermore, the shear performance of epoxy joints significantly deteriorated when the interface defects exceeded 30%, resulting in the failure mode transforming from shear failure to interface failure.

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Section: Introductionmentioning

confidence: 99%

Shear Performance of Epoxy Joints in a Precast Bridge Deck Considering Constraint Effects

Zhang

Wang

et al. 2023

Polymers

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“…Al-Rousan et al 14 study the influence of confining stress and concrete compressive strength on the shear behavior of dry single-keyed joints through non-linear FEA simulation, and a shear capacity formula was proposed. Zhang et al 15 performed full-scale tests on the shear behavior of multiple-keyed epoxy joints, and proposed a new formula considering the uneven distribution of shear stress. Alcalde’s 16 test results show that the average shear stress transferred across the joint decreases with the number of keys but this influence is less appreciated as the confining stress increases.…”

Section: Introductionmentioning

confidence: 99%

Shear behavior and construction method of steel shear keyed joints in precast segmental beams

Zou

Xiang

2023

Sci Rep

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The joints between segments represent weak points and introduce discontinuity into structures, therefore they are particularly significant in precast concrete segmental bridges. In this study, a new steel shear key was designed, and 6 full-scale tests were conducted. Various shear keys and joint types were taken as experimental parameters to study crack propagation, failure mode, shear slip, ultimate bearing capacity, and the residual bearing capacity of various joints under direct shear loading. The results show that the stiffness and shear capacity of steel shear keyed joints were higher than concrete key joints, and the structural system was more stable than concrete keyed joints at the moment of cracking. Both the concrete key and steel key epoxied joints suffered direct shear failure. However, different to the concrete epoxied joints which experienced brittle failure, steel key epoxied joints demonstrated a large residual capacity. Based on traditional segmental bridges construction, construction methods involving steel shear keyed joints included short-line match, long-line match, and modular methods are introduced. Finally, the feasibility of steel shear keyed joints construction was verified via engineering tests.

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“…Precast segmental concrete beam (PSCB) is a popular and widely used construction technique in bridge engineering due to its significant benefits of economy, high-quality control, fast construction, and low environmental impact [1][2][3][4]. Especially for bridge constructions in mountainous and urban areas, PSCB is usually the preferred option [5].…”

Section: Introductionmentioning

confidence: 99%

Proposals for Flexural Capacity Prediction of Precast Segmental Concrete Beam Prestressed with Internal Un-Bonded CFRP Tendons

et al. 2023

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The application of CFRP tendons in precast segmental concrete beams (PSCB) as internal un-bonded prestressing reinforcement is a newly developed scheme to improve structural flexural performance. The stress increment of the un-bonded tendon, depending on the whole structural deformation, is a crucial value to be predicted for flexural capacity design. Due to the discontinuity of the opening joints, the deformation modes of segmental beams differ from the monolithic ones. The existing prediction methods built for monolithic beams can not be directly used for segmental beams. In this paper, the new prediction equations of the tendon stress increment and flexural capacity were put forward for PSCB with internal un-bonded CFRP tendons (PSCB-IUCFRP). Firstly, the differences between the deformation modes of monolithic and segmental beams were compared and clarified based on the numerical model analysis. Then, a parametric analysis was conducted on 162 numerical models, and the results were employed to evaluate the applicability of existing methods for PSCB-IUCFRP. The predictions of the ACI 318-14 model and the AASHTO LRFD model were both conservative and scattering compared with numerical results. The ACI 440.4R model underestimated the tendon stress increments of beams under one-point loading but overestimated it for those under two-point loading. According to the failure mode of PSCB-IUCFRP, a simplified curvature distribution mode was assumed, and the relation between tendon elongation and structural deflection was derived. The prediction equations for PSCB-IUCFRP were proposed using the back-calculated plastic hinge length. Compared with existing methods, the proposed equations considered the deformation characteristic of segmental beams and had clear physical significance. The predictions of the proposed method were in good agreement with the numerical and experimental results. Furthermore, a balanced prestressing reinforcement ratio equation is proposed for PSCB-IUCFRP to avoid tendon rupture-controlled failure. The proposed equations provide suggestions for the flexural design of PSCB-IUCFRP and will help to popularize this new structure.

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Full-scale experimental study on shear behavior of multiple-keyed epoxy joints in precast concrete segmental bridges

Cited by 10 publications

References 21 publications

Shear Performance of Epoxy Joints in a Precast Bridge Deck Considering Constraint Effects

Shear Performance of Epoxy Joints in a Precast Bridge Deck Considering Constraint Effects

Shear behavior and construction method of steel shear keyed joints in precast segmental beams

Proposals for Flexural Capacity Prediction of Precast Segmental Concrete Beam Prestressed with Internal Un-Bonded CFRP Tendons

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