Article
Engineering, Civil
Ahmed Ibrahim Hassanin, Hesham Fawzy Shabaan, Ahmed Ibrahim Elsheikh
Summary: This study presents an experimental program on scaled bridge composite steel-concrete beams strengthened with external post-tensioning tendons, focusing on the fundamental cyclic loading behavior and the effect of shear connection degree. The results show that external post-tensioning significantly improved the performance of composite beams under cyclic loading, enhancing ultimate capacity and residual stiffness.
Article
Construction & Building Technology
Nabila Rezende de Almeida Cerqueira, Vitor Moreira de Alencar Monteiro, Felipe Rodrigues de Souza, Daniel Carlos Taissum Cardoso, Flavio de Andrade Silva
Summary: This study investigated the behavior of pre-cracked ultra-high performance concrete (UHPC) under flexural fatigue by quantifying its mechanical deterioration using crack mouth opening displacement (CMOD), stiffness, and energy dissipation rate. The flexural fatigue tests were conducted at a frequency of 6 Hz on notched pre-cracked prisms at different maximum load levels. The results showed that UHPC had a longer fatigue life and better performance compared to 50 MPa SFRC. Additionally, a linear relationship between residual bending strength and initial stiffness was observed, and equations were proposed to predict fatigue life based on the upper load limit.
CONSTRUCTION AND BUILDING MATERIALS
(2023)
Article
Construction & Building Technology
Rita Giao, Valter Lucio, Carlos Chastre
Summary: This paper presents an experimental study on the improvement of beam behaviour by strengthening critical zones using two solutions: unbounded post-tension tendon strengthening and unbounded post-tensioning with jacketing of reinforced grout. The study demonstrates that both strengthening methods enhance the seismic performance of the structural frame system.
Article
Engineering, Mechanical
Yanpeng Wang, Jie Li
Summary: This study investigates the influence of randomness at the material level on fatigue behaviors of reinforced concrete structures, resulting in significant scatter in fatigue lives, failure modes, deflections, and strains of the specimens, with different failure modes explained by competing mechanisms. The S-Nc curve approach was found to be unable to accurately estimate the failure modes of the specimens.
INTERNATIONAL JOURNAL OF FATIGUE
(2021)
Article
Construction & Building Technology
Jongho Park, Jungbhin You, Sun-Kyu Park, Sungnam Hong
Summary: The study verified the flexural behavior and fatigue performance of textile-reinforced mortar (TRM)-strengthened beams, finding that using straightened carbon textile can improve efficiency. Under cyclic loading, the efficiency of TRM-strengthened beams was lower than monotonic loading, with alkali-resistant (AR) glass and non-straightened carbon having an average efficiency of 0.86 compared to monotonic loading.
Article
Construction & Building Technology
Sung-Gul Hong, Woo-Young Lim
Summary: This study investigates the behavior of shear-dominant beams strengthened with 150 MPa ultra-high-performance concrete (UHPC) through experiments on thirteen full-scale test specimens. The test variables include the strengthening method, thickness of the UHPC jackets, and fiber volume fraction of the UHPC. The results showed that the UHPC jacketing technique significantly improved the load resistance, ductility, and stiffness of the shear-dominant beams.
CONSTRUCTION AND BUILDING MATERIALS
(2023)
Article
Engineering, Civil
John Bressan, Faouzi Ghrib, Amr El Ragaby
Summary: The effectiveness of carbon and PBO fabric-reinforced cementitious matrix (C-FRCM and PBO-FRCM) systems in rehabilitating reinforced concrete beams affected by corrosion was investigated. The FRCM strengthening significantly increased the yield and ultimate capacity of the corroded beams, and successfully maintained their strength over the cyclic life under cyclic loading. The FRCM systems extended the cyclic life up to five times compared to nonstrengthened control beams.
JOURNAL OF COMPOSITES FOR CONSTRUCTION
(2022)
Article
Engineering, Civil
Sadegh Mansouri, Reza Morshed, Davood Mostofinejad
Summary: The present study introduces an innovative technique for flexural strengthening of reinforced concrete beams subjected to constant loading and explores its efficacy through experimental evaluation. The NSM pre-stressed steel rebars lead to significant increases in the ultimate flexural capacity of the beams and decrease initial cracking and deflection.
Article
Chemistry, Multidisciplinary
Zhimei Zhang, Tao Li
Summary: This study investigated the deformation performance of CFRP-strengthened corroded RC beams under fatigue loading using a numerical analysis method based on the fatigue damage failure process and the fatigue constitutive models of each material. The finite element software ABAQUS was employed to model and analyze the beams, considering the degradation of bond performance between rusted reinforcement and concrete. A formula for calculating the mid-span deflection of CFRP-strengthened corroded RC beams under fatigue loading was established through regression analysis. The formula was validated to be accurate and reliable through comparison with experimental data.
APPLIED SCIENCES-BASEL
(2023)
Article
Engineering, Civil
Mingke Deng, Min Zhang, Fudong Ma, Fangyuan Li, Hongzhe Sun
Summary: This study investigated the effectiveness of highly ductile fiber-reinforced concrete (HDC) in improving the failure mode and ductility of over-reinforced concrete beams. The experimental results showed that applying HDC to strengthen the compression zone of over-reinforced concrete beams was highly effective in changing the brittle failure mode and increasing the deformation capacity. Increasing the thickness of the strengthening layer and ensuring coordination with the existing beam can further enhance the deformation capacity.
ENGINEERING STRUCTURES
(2021)
Article
Engineering, Civil
Shiyao Zhu, Y. X. Zhang, C. K. Lee
Summary: Hybrid engineered cementitious composites (ECC) have potential applications in structural components, and this study investigates the mechanical properties of hybrid ECCs with different fiber contents. The results show that hybrid fibers enhance both static and fatigue performances of ECC, and the ECC with 1.25%+0.75% PE-ST fibers exhibits balanced performance.
ENGINEERING STRUCTURES
(2022)
Article
Engineering, Multidisciplinary
Ghada M. Hekal, Alaa A. Bashandy, Ebrahim H. Abdou, Amgad Elbehiry, Dongxi Xie, Khalid Elbaz
Summary: This study investigates the impact of openings and different strengthening materials on arched beams. It consists of three stages: studying the effect of openings on curved beams, examining the effect of various strengthening materials on deflection and failure load, and analyzing the differences between beams with and without openings using Finite Element models. The findings show that openings negatively affect the load, deflection, and ductility ratio of arched beams. Steel plates provide the highest ultimate load, outperforming carbon fiber and glass fiber sheets. The study offers valuable solutions for controlling, repairing, and supporting structures.
ALEXANDRIA ENGINEERING JOURNAL
(2023)
Article
Construction & Building Technology
Gaochuang Cai, Konstantinos Daniel Tsavdaridis, Amir Si Larbi, Phil Purnell
Summary: This study proposes a simplified design approach to predict the flexural behavior of reinforced concrete beams strengthened by high-performance textile reinforced mortar under cyclic loads. Factors such as reinforcement ratios, interface bond, and textile reinforcement ratio have significant influence on the flexural behavior and failure modes of the strengthened beams. Simplified models based on fib and AIJ standards are suggested for predicting flexural capacity and evaluating flexural curves with good accuracy.
CONSTRUCTION AND BUILDING MATERIALS
(2021)
Article
Engineering, Civil
Shamsad Ahmad, Abdulla M. A. Sharif, Mohammed A. Al-Osta, Mesfer M. Al-Zahrani, Abdulrahman M. Sharif, Mohammed A. Al-Huri
Summary: This paper presents a study on the flexural behavior of pre-damaged reinforced concrete beams strengthened with different configurations of ultra-high-performance fiber-reinforced concrete layers. The experimental results showed that the degree of pre-damaging and the strengthening configuration significantly affected the flexural performance of the beams. The analytical models developed in this study accurately predicted the ultimate load-bearing capacities of the strengthened beams.
Article
Construction & Building Technology
Zhi-qiang Li, Wei Hou, Guan Lin
Summary: This study investigated the flexural behavior of reinforced concrete beams strengthened with BFRP or HSS bars, finding that BFRP bars dominated in the failure of beams while HSS bars significantly improved flexural capacity due to their high stiffness and strength. Comparisons between ECC and polymer mortar matrices showed that ECC resulted in larger enhancements in load capacities, confirming the excellent strain compatibility of BFRP bars and ECC matrix. Additionally, a flexural theoretical analysis was proposed and verified through experimental results.
CONSTRUCTION AND BUILDING MATERIALS
(2021)