Refined calculation of time-dependent prestress losses in prestressed concrete girders

Yang, Ming-Fang; Gong, Jinxin; Yang, Xiaoguang

doi:10.1080/15732479.2020.1712438

Cited by 10 publications

(6 citation statements)

References 14 publications

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“…Kim et al [14] evaluated the friction coefficients between the strand and the duct with smart strands on the basis of a full-scale test specimen and two actual long-span girder bridges. Yang et al [15] developed a refined method for the calculation of time-dependent prestress losses in prestressed concrete girders and verified the proposed method with numerical results. However, the existing studies on prestress loss are mainly for bridges and beams, and mostly involve steel strands.…”

Section: Introductionmentioning

confidence: 98%

Theoretical Study on Prestress Loss in Cross-Tensioned Concrete Pavement with BFRP Tendons

Zhang

Huang

2020

Applied Sciences

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Cross-tensioned concrete pavement can reduce transverse joints and cracks and improve the durability of the pavement, and the decrease in slab thickness can be achieved without damaging the performance of the pavement. However, the corrosion of the steel can cause serious damage to the pavement structure, resulting in higher maintenance costs and shorter service life. Basalt fiber-reinforced polymer (BFRP) has been proven to be an effective alternative in both jointed plain concrete pavement (JPCP) and continuously reinforced concrete pavement (CRCP) due to its lightweight and corrosion-resistant properties. In this paper, a systematic theoretical method for determining the prestress loss of BFRP tendons in cross-tensioned concrete pavement was proposed, with the impact of the slab width and distribution angle of the prestressed tendon on the prestress loss being studied and compared to the results of traditional steel strands. Results showed that the proportion of the prestress loss due to anchorage deformation and prestress retraction in the prestressing stage rose with the increase in distribution angle and the decrease in slab width, while the prestress loss during the in-service stage was a constant value for both BFRP tendons and steel strands. The prestress loss of BFRP tendons was far lower than that of steel strands in both prestressing stage and in-service stage for a given slab width (3 m, 4.5 m, 9.0 m, 12.75 m) and distribution angle (20°, 25°, 30°, 35°, 40°, 45°), and the difference ranged from 6.4% to 16%, signifying the feasibility of BFRP tendons in cross-tensioned concrete pavement. Overall, the smaller the slab width, the greater the difference of the prestress loss between BFRP tendons and steel strands.

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Section: Introductionmentioning

confidence: 98%

Theoretical Study on Prestress Loss in Cross-Tensioned Concrete Pavement with BFRP Tendons

Zhang

Huang

2020

Applied Sciences

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“…The scale of highway bridges in China is huge [1], and many old bridges have a large number of structural and utilization problems, such as the corrosion of steel bars, serious aging of concrete, concrete spalling, excessive crack width, insufficient bearing capacity, and high prestressing losses [2][3][4][5][6]. More than 30% of bridges that are currently in use require strengthening and repair, not just in our nation but also in developed nations like the US and Canada [7]. When it comes to renovating both new and old bridges, ultra-highperformance concrete (UHPC) is a novel kind of strengthening material that offers several benefits [8][9][10][11][12][13].…”

Section: Introductionmentioning

confidence: 99%

Numerical Simulation Analysis of the Bending Performance of T-Beams Strengthened with Ultra-High-Performance Concrete Based on the CDP Model

Long,

Jiang,

Zou

et al. 2024

Buildings

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In bridge reinforcement projects, damaged T-beams are the most common objects for reinforcement, yet the interface bonding and bending performance of UHPC reinforcement on T-beams have hardly been studied. To ensure the reliability and stability of UHPC-strengthened T-beams in practical applications, this study introduced a post-installed rebar bonding technique to efficiently connect T-beams with UHPC layers. Initially, using ABAQUS software [2020 version] for finite element simulation, this study investigated the effects of various post-installed rebar parameters (horizontal spacing, yield strength, diameter, and matrix concrete strength) on the shear performance of the UHPC and RC interface, obtaining the optimal connection parameters. Subsequently, by comparing shear formulas in domestic and international standards, a new UHPC-RC steel bar interface shear strength theoretical formula with 93.6% accuracy was derived. Finally, finite element simulations analyzed the impact of different post-installed reinforcing bar layout forms and longitudinal spacing, as well as UHPC-strengthened location and layer thickness, on the bending performance of damaged T-beams. The results showed a good match between simulation outcomes and experimental results, applicable for further reinforcement analysis of T-beams. When the horizontal spacing of post-installed rebars is 12d, with diameters ranging from 10 mm to 14 mm, their anchoring capability is efficiently utilized. A square form of a post-installed rebar with a longitudinal spacing of 300 mm effectively improves the ultimate bending load capacity of the strengthened beam. The simulation analysis and theoretical results help in the design and application of post-installed steel connections and UHPC-strengthened structures in UHPC-strengthened reinforced concrete T-beam structures.

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“…It can be used for multi-stage loading and prestressing. Yang et al [ 20 ] used the median integral theorem based on the shrinkage creep models of FIB MC 2010 and AASHTO-LRFD 2014 to create a refined method for estimating the time-varying prestress loss. Compared with the numerical results obtained by the step-by-step method, it has good accuracy.…”

Section: Introductionmentioning

confidence: 99%

Long-Term Prestress Loss Calculation Considering the Interaction of Concrete Shrinkage, Concrete Creep, and Stress Relaxation

Han

Tian

et al. 2023

Materials

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In order to accurately calculate the long-term prestress losses of prestressed tendons, a time-varying model of long-term prestress loss considering the interaction between concrete shrinkage, creep, and the stress relaxation of prestressed tendons was constructed. Then, a method for calculating the long-term prestress losses of concrete structures was developed. A long-term prestress loss test of a prestressed concrete T-beam in a long-term field test environment was carried out. The measured values of long-term prestress losses are compared with the calculated results of JTG 3362-2018, AASHTO LRFD-2007, and the time-varying law model. The results show that the long-term effective tension of the T-beam decreases gradually with the increase in the load holding time. At the beginning of loading, the tensile force changes rapidly and then gradually slows down. The later the tensile age or the higher the initial loading stress level, the smaller the long-term prestress losses of the prestressed tendons. The long-term prestress loss values calculated by JTG 3362-2018, AASHTO LRFD-2007, and the time-varying law model increase with the increase in the load holding time. In the early stage of loading, the rate of change slows down and tends to be stable. The calculated results of JTG 3362-2018 and AASHTO LRFD-2007 are significantly different from the measured values. However, the calculated results of the time-varying law model are in good agreement with the measured values. The average coefficients of variation of the long-term prestress loss calculated by JTG 3362-2018, AASHTO LRFD-2007, and the time-varying law model are 17%, 10%, and 5%, respectively. The time-varying law model of the long-term prestress losses of prestressed tendons is accurate, and the long-term prestress loss of prestressed reinforcement can be predicted effectively.

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Refined calculation of time-dependent prestress losses in prestressed concrete girders

Cited by 10 publications

References 14 publications

Theoretical Study on Prestress Loss in Cross-Tensioned Concrete Pavement with BFRP Tendons

Theoretical Study on Prestress Loss in Cross-Tensioned Concrete Pavement with BFRP Tendons

Numerical Simulation Analysis of the Bending Performance of T-Beams Strengthened with Ultra-High-Performance Concrete Based on the CDP Model

Long-Term Prestress Loss Calculation Considering the Interaction of Concrete Shrinkage, Concrete Creep, and Stress Relaxation

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