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Article
Publication date: 20 December 2023

Lifeng Wang, Jiwei Bi, Long Liu and Ziwang Xiao

This paper presents the experimental and numerical results of the bending properties of low-height prestressed T-beams. The purpose is to study the bearing capacity, failure state…

Abstract

Purpose

This paper presents the experimental and numerical results of the bending properties of low-height prestressed T-beams. The purpose is to study the bearing capacity, failure state and strain distribution of low-height prestressed T-beams.

Design/methodology/approach

First, two 13 m-long full-size test beams were fabricated with different positions of prestressed steel bundles in the span. The load–deflection curves and failure patterns of each test beam were obtained through static load tests. Secondly, the test data were used to validate the finite element model developed to simulate the flexural behavior of low-height prestressed T-beams. Finally, the influence of different parameters (the number of prestressed steel bundles, initial prestress and concrete strength grade) on the flexural performance of the test beams is studied by using a finite element model.

Findings

The test results show that when the distance of the prestressed steel beam from the bottom height of the test beam increases from 40 to 120 mm, the cracking load of the test beam decreases from 550.00 to 450.00 kN, reducing by 18.18%, and the ultimate load decreases from 1338.15 to 1227.66 kN, reducing by 8.26%, therefore, the increase of the height of the prestressed steel beam reduces the bearing capacity of the test beam. The numerical simulation results show that when the number of steel bundles increases from 2 to 9, the cracking load increases by 183.60%, the yield load increases by 117.71% and the ultimate load increases by 132.95%. Therefore, the increase in the number of prestressed steel bundles can increase the cracking load, yield load and ultimate load of the test beam. When the initial prestress is from 695 to 1,395 MPa, the cracking load increases by 69.20%, the yield load of the bottom reinforcement increases by 31.61% and the ultimate load increases by 3.97%. Therefore, increasing the initial prestress can increase the cracking load and yield load of the test beam, but it has little effect on the ultimate load. The strength grade of concrete increases from C30 to C80, the cracking load is about 455.00 kN, the yield load is about 850.00 kN and the ultimate load is increased by 4.90%. Therefore, the improvement in concrete strength grade has little influence on the bearing capacity of the test beam.

Originality/value

Based on the experimental study, the bearing capacity of low-height prestressed T-beams with different prestressed steel beam heights is calculated by finite element simulation, and the influence of different parameters on the bearing capacity is discussed. This method not only ensures the accuracy of bearing capacity assessment, but also does not require a large number of samples and has a certain economy. The study of prestressed low-height T-beams is of great significance for understanding the principle and application of prestressed technology. Research on the mechanical behavior and performance of low-height prestressed T beams can provide a scientific basis and technical support for the design and construction of prestressed concrete structures. In addition, the study of prestressed low-height T-beams can also provide a reference for the optimization design and construction of other structural types.

Details

International Journal of Structural Integrity, vol. 15 no. 1
Type: Research Article
ISSN: 1757-9864

Keywords

Article
Publication date: 19 August 2021

Sheng Peng, Lu-jun Cai, Tian-hua Jiang and Xu Kai

The purpose of this paper is to investigate the explosive performance and explosion damage mechanism of T-beam bridge structure.

Abstract

Purpose

The purpose of this paper is to investigate the explosive performance and explosion damage mechanism of T-beam bridge structure.

Design/methodology/approach

On the basis of the existing specification, two T-beam bridge models were designed and fabricated. Test specimens of different explosive dosage and different blast height were carried out. The mechanical process, failure mode, blast damage model, damage identification mechanism and blast evolution law and quantitative evaluation were taken into account.

Findings

The results revealed that the web plate fracture failure is the key to the unstable failure of the whole T-beam bridge. The explosion failure phenomenon and blast damage evaluation criterion of RC T-beam bridge was divided into five stages: the original cracks stage of concrete material (D = 0 ∼ 0.1), the fractures initiation stage of concrete material (D = 0.1 ∼ 0.3), the stable expansion stage of cracks in concrete material (D = 0.3 ∼ 0.55), the unstable expansion stage of cracks in concrete material (D = 0.55 ∼ 0.8), the explosion fracture of steel bars and the overall instability and damage of the bridge (D = 0.8 ∼ 1.0), which can also be described as basically intact, slight damage, moderate damage, severe damage and collapsed.

Social implications

The research result will provide basis for the antiknock evaluation and damage repair technical specifications of the RC T-beam bridge.

Originality/value

The research results of damage evaluation serve as a basis for damage repair and reinforcement of bridge structures after explosion.

Details

Sensor Review, vol. 41 no. 4
Type: Research Article
ISSN: 0260-2288

Keywords

Article
Publication date: 13 March 2020

Hongshuai Gao and Quansheng Sun

With the rapid development of transportation and the continuous increase of traffic volume and load level, some bridges cannot meet the use requirements, and the demand for bridge…

Abstract

Purpose

With the rapid development of transportation and the continuous increase of traffic volume and load level, some bridges cannot meet the use requirements, and the demand for bridge strengthening is growing. Furthermore, bridges are affected by factors such as structure and external environment. With the increase of service time, the deterioration of bridges is also increasing. In order to avoid the waste caused by demolition and reconstruction, it is necessary to strengthen the bridge accurately and effectively to improve the bearing capacity and durability, eliminate the hidden dangers, and ensure the normal operation of the bridge. It is of great significance to study the strengthening methods. Compared with traditional strengthening methods, the advantages of using new materials and new technology to strengthen bridges are more obvious. This paper introduces a new method for bridge active strengthening, called modified polyurethane cement with prestressed steel wire rope (MPC-PSWR).

Design/methodology/approach

Relying on the actual bridge strengthening project, five T-beams of the superstructure of the bridge are taken as the research object, and the T-beams before and after strengthening are evaluated, calculated, and analyzed by finite element simulation and field load test. By comparing the numerical simulation and load test data, the strengthening effect of modified polyurethane cement with prestressed steel wire rope on stiffness, strength, and bearing capacity is verified, which proves that the strengthening effect of MPC-PSWR is effective for strengthening.

Findings

MPC-PSWR can effectively reduce deflection, cracks, and strain, thereby significantly improving the flexural capacity of existing bridges. Under the design load, the deflection, crack width, and stress of the strengthened beams decrease in varying degrees. The overall performance of the beams strengthened by MPC-PSWR has been improved, and the flexural performance meets the requirements of the code.

Originality/value

MPC-PSWR is an innovative bridge-strengthening method. Through the analysis of its MPC-PSWR effect, the MPC-PSWR method with reference to significance for the design and construction of similar bridges is put forward.

Details

International Journal of Structural Integrity, vol. 11 no. 3
Type: Research Article
ISSN: 1757-9864

Keywords

Article
Publication date: 16 April 2020

Zizheng Liu, Tianlai Yu and Linlin Zhang

The effects of fatigue load level and plate thickness on the fatigue performance of reinforced concrete T-beam bridges.

Abstract

Purpose

The effects of fatigue load level and plate thickness on the fatigue performance of reinforced concrete T-beam bridges.

Design/methodology/approach

Fatigue load tests were performed based on the fatigue damage theory of reinforced concrete, combined with finite element model analysis. The other conditions are controlled separately, and the fatigue performance of the T-beam bridge carriageway slab under different fatigue load levels and different plate thicknesses is studied.

Findings

The fatigue process of the carriageway slab of a reinforced concrete T-beam bridge is divided into three stages: fatigue damage generation, fatigue damage development and fatigue failure. Under certain other conditions, as the fatigue load level increases, the fatigue damage of the carriageway slab accelerates; as the thickness of the carriageway slab increases, the fatigue resistance of the carriageway slab improves.

Research limitations/implications

Tests and simulations have been carried out, but have not been applied to actual engineering for the time being.

Practical implications

Increasing the thickness of the carriageway slab in actual engineering is conducive to improving the fatigue performance of the bridge, and heavy-duty traffic has a greater impact on the durability of the bridge.

Social implications

It has certain reference value for bridge design, inspection and subsequent maintenance and reinforcement.

Originality/value

The originality of this article lies in designing and carrying out static and cyclic load tests separately, while introducing material damage models based on a large number of references and combining finite element analysis to consider the impact of a specific factor on fatigue performance. The test and analysis results can provide reference for bridge design and inspection.

Details

International Journal of Structural Integrity, vol. 12 no. 2
Type: Research Article
ISSN: 1757-9864

Keywords

Article
Publication date: 17 June 2021

Kexin Zhang, Qi Tianyu, Li Dachao, Xue Xingwei, Fayue Wu and Xinfeng Liu

In order to understand the status of the bridge reinforcement process, the construction process monitoring of the reinforced bridge is carried out. The T-beam bridge was tested…

Abstract

Purpose

In order to understand the status of the bridge reinforcement process, the construction process monitoring of the reinforced bridge is carried out. The T-beam bridge was tested using the truck loading test. The displacements and concrete strains of the bridge at mid-span were measured during the test.

Design/methodology/approach

This paper describes an innovative technique, external prestressing, used to strengthen a 36-year-old prestressed T-beam bridge. This paper introduces the construction process of the prestressed reinforcement method, and makes a theoretical analysis of the reinforced bridge through the establishment of the reinforcement model.

Findings

This study showed that the structural capacity and performance of the bridge were enhanced with externally prestressed steel strand strengthening.

Originality/value

The innovative reinforcement method of prestressed T-shaped bridge is put forward, which has guiding significance for similar bridge reinforcement and maintenance.

Details

International Journal of Structural Integrity, vol. 12 no. 6
Type: Research Article
ISSN: 1757-9864

Keywords

Article
Publication date: 18 March 2014

Mohannad Naser, Rami Hawileh and Hayder Rasheed

This paper presents a numerical study that investigates the performance of reinforced concrete (RC) T-beams externally strengthened with carbon fibre reinforced polymer (CFRP…

Abstract

This paper presents a numerical study that investigates the performance of reinforced concrete (RC) T-beams externally strengthened with carbon fibre reinforced polymer (CFRP) plates when subjected to fire loading. A finite element (FE) model is developed and a coupled thermal-stress analysis was performed on a RC beam externally strengthened with a CFRP plate tested by other investigators. The spread of temperature at the CFRP-concrete interface and reinforcing steel, as well as the mid-span deflection response is compared to the measured experimental data. Overall, good agreement between the measured and predicted data is observed. The validated model was then used in an extensive parametric study to further investigate the effect of several parameters on the performance of CFRP externally strengthened RC beams under elevated temperatures. The variables of the parametric study include applying different fire curves and scenarios, different applied live load combinations as well as the effect of using different insulation schemes with different types and thicknesses. Several observations and conclusions were drawn from the parametric investigation. It could be concluded that successful FE modeling of this structural member when exposed to thermal and mechanical loading would provide a valid economical and efficient alternative solution to the expensive and time consuming experimental testing.

Details

Journal of Structural Fire Engineering, vol. 5 no. 1
Type: Research Article
ISSN: 2040-2317

Keywords

Article
Publication date: 12 March 2020

Tianlai Yu, Linlin Zhang and Zizheng Liu

The fatigue problems of the carriageway slabs of reinforced concrete rib-beam bridges were studied. The analysis of the carriageway slabs could not achieve the actual stress state.

Abstract

Purpose

The fatigue problems of the carriageway slabs of reinforced concrete rib-beam bridges were studied. The analysis of the carriageway slabs could not achieve the actual stress state.

Design/methodology/approach

Based on this characteristic, the reinforced concrete T-beam group structure system was taken as the research object. Four scale models of the carriageway slabs of reinforced concrete ribbed bridges were designed. The fatigue failure modes and actual fatigue resistance of the carriageway slabs with different length-to-side ratios were systematically studied through static load and fatigue experiments. Based on this, the concrete damage plasticity model (CDP model) was combined with numerical simulation analysis to study the influence of the length-to-short-side ratio of the carriageway slab on the fatigue performance and the remaining bearing capacity.

Findings

The results show that the fatigue failure of the carriageway slab is a three-stage failure; the ratio of the long and short sides has a significant effect on the fatigue performance of the carriageway slab. Under the same fatigue load level, the smaller the ratio of the long and short sides of the carriageway slab.

Originality/value

The fatigue resistance of the unidirectional board is significantly lower than that of the bidirectional board. It is recommended to use the bidirectional board in actual engineering design.

Details

International Journal of Structural Integrity, vol. 12 no. 2
Type: Research Article
ISSN: 1757-9864

Keywords

Article
Publication date: 12 June 2017

Danie Roy Anasco Bastin, Umesh Kumar Sharma and Pradeep Bhargava

The main aim of this research was to investigate the effectiveness of various strengthening techniques in restoring the structural performance of reinforced concrete (RC) beams…

Abstract

Purpose

The main aim of this research was to investigate the effectiveness of various strengthening techniques in restoring the structural performance of reinforced concrete (RC) beams damaged by elevated temperatures.

Design/methodology/approach

Three different strengthening techniques, namely, high-strength fibre reinforced concrete (HSFRC), ferrocement (FC) jacketing and externally bonded fibre-reinforced polymer (FRP) were used. Series of RC beams were casted, heated, strengthened and tested to investigate the influence of various variables. The variables of the study were type of strengthening and level of heat damage.

Findings

Externally bonded FRP was found to be the best among the various techniques, especially with respect to strength and stiffness restoration. On the contrary, the FRP strengthening was not that effective in restoring the energy absorption capacity of beams compared to HSFRC and FC techniques of strengthening. The chosen strengthening techniques were able to restore the failure mode of beams to flexural failure, which was found to have changed to shear failure in case of heated unstrenghthened beams.

Originality/value

This research program has contributed to the fundamental understanding of designing post fire retrofit solutions for RC beams.

Details

Journal of Structural Fire Engineering, vol. 8 no. 2
Type: Research Article
ISSN: 2040-2317

Keywords

Content available
Article
Publication date: 1 December 2002

633

Abstract

Details

Anti-Corrosion Methods and Materials, vol. 49 no. 6
Type: Research Article
ISSN: 0003-5599

Keywords

Article
Publication date: 29 March 2024

Aminuddin Suhaimi, Izni Syahrizal Ibrahim and Mariyana Aida Ab Kadir

This review paper seeks to enhance knowledge of how pre-loading affects reinforced concrete (RC) beams under fire. It investigates key factors like deflection and load capacity to…

Abstract

Purpose

This review paper seeks to enhance knowledge of how pre-loading affects reinforced concrete (RC) beams under fire. It investigates key factors like deflection and load capacity to understand pre-loading's role in replicating RC beams' actual responses to fire, aiming to improve fire testing protocols and structural fire engineering design.

Design/methodology/approach

This review systematically aggregates data from existing literature on the fire response of RC beams, comparing scenarios with (WP) and without pre-loading (WOP). Through statistical tools like the two-tailed t-test and Mann–Whitney U-test, it assesses deflection extremes. The study further examines structural responses, including flexural and shear behavior, ultimate load capacity, post-yield behavior, stiffness degradation and failure modes. The approach concludes with a statistical forecast of ideal pre-load levels to elevate experimental precision and enhance fire safety standards.

Findings

The review concludes that pre-loading profoundly affects the fire response of RC beams, suggesting a 35%–65% structural capacity range for realistic simulations. The review also recommended the initial crack load as an alternative metric for determining the pre-loading impact. Crucially, it highlights that pre-loading not only influences the fire response but also significantly alters the overall structural behavior of the RC beams.

Originality/value

The review advances structural fire engineering with an in-depth analysis of pre-loading's impact on RC beams during fire exposure, establishing a validated pre-load range through thorough statistical analysis and examination of previous research. It refines experimental methodologies and structural design accuracy, ultimately bolstering fire safety protocols.

Details

Journal of Structural Fire Engineering, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 2040-2317

Keywords

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