scholarly journals Application of X-Shaped CFRP Ropes for Structural Upgrading of Reinforced Concrete Beam–Column Joints under Cyclic Loading–Experimental Study

Fibers ◽  
2021 ◽  
Vol 9 (7) ◽  
pp. 42
Author(s):  
Emmanouil Golias ◽  
Adamantis G. Zapris ◽  
Violetta K. Kytinou ◽  
Mourhat Osman ◽  
Michail Koumtzis ◽  
...  
Keyword(s):  
Reinforced Concrete ◽  
Load Capacity ◽  
Reinforced Concrete Beam ◽  
Hysteretic Behavior ◽  
Rc Beam ◽  
Near Surface ◽  
Near Surface Mounted ◽  
Column Joint ◽  
Reference Specimens ◽  
Strengthening Technique

The effectiveness of externally applied fiber-reinforced polymer (FRP) ropes made of carbon fibers in X-shape formation and in both sides of the joint area of reinforced concrete (RC) beam–column connections is experimentally investigated. Six full-scale exterior RC beam–column joint specimens are tested under reverse cyclic deformation. Three of them have been strengthened using carbon FRP (CFRP) ropes that have been placed diagonally in the joint as additional, near surface-mounted reinforcements against shear. Full hysteretic curves, maximum applied load capacity, damage modes, stiffness and energy dissipation values per each loading step are presented and compared. Test results indicated that joint sub assemblages with X-shaped CFRP ropes exhibited improved hysteretic behavior and ameliorated performance with respect to the reference specimens. The effectiveness and the easy-to-apply character of the presented strengthening technique is also discussed.

scholarly journals A STATE OF THE ART REVIEW OF EFFICIENCY THE FLEXURAL STRENGTHENING OF REINFORCED CONCRETE BEAM BY USING FIBER REINFORCEMENT POLYMER MATERIALS

2021 ◽  
Vol 25 (Special) ◽  
pp. 4-88-4-99
Author(s):  
Wissam S. Abdullah ◽  
◽  
Hassan F. Hassan ◽  
Keyword(s):  
Reinforced Concrete ◽  
Reinforced Concrete Beam ◽  
Polymer Materials ◽  
Fiber Reinforced Polymer ◽  
Maintenance Cost ◽  
Rc Beam ◽  
Fiber Reinforced ◽  
Construction Time ◽  
Near Surface ◽  
Reinforced Polymer

Fiber Reinforced Polymer (FRP) materials are commonly used in civil engineering construction purposes owing their advantages like lightweight, corrosion resistance, high strength, various types available, ease of installation, lower installation costs, shorter construction time and lower maintenance cost [1]. Over the last few decades, flexural Reinforced Concrete (RC) beams reinforcement and maintenance with Near-Surface Mounted (NSM) or Externally Bonded Reinforcement (EBR) Fiber Reinforced Polymer has gained considerable interest and obtained widespread acceptance among civil engineers [2]. This paper reviews previous research on RC beam strengthening by NSM or EBR FRP technique and show the effects of FRP strengthening on flexural strength of RC beam.

Calculation of Shear Capacity of Steel Reinforced Concrete Beams Strengthened with Near-Surface Mounted CFRP Rods

2012 ◽  
Vol 193-194 ◽  
pp. 852-854
Author(s):  
Wei Hua Chen ◽  
Mei Qin Wu
Keyword(s):  
Reinforced Concrete ◽  
Reinforced Concrete Beam ◽  
Shear Capacity ◽  
Reinforced Concrete Beams ◽  
Rc Beams ◽  
Near Surface ◽  
Steel Reinforced Concrete ◽  
Carbon Fiber Reinforce Polymer ◽  
Near Surface Mounted ◽  
Fiber Reinforce

Some calculated methods of shear capacity of RC beams strengthened with NSM(near-surface mounted) CFRP(Carbon fiber reinforce polymer) rods are reviewed based on the experimental data on shear capacity of RC beams strengthened with NSM CFRP rods. Therefore, according to the destruction forms of steel reinforced concrete beam strengthened with NSM CFRP rods, the formula for calculating the shear capacity of the beam is given. The formula is expressed clearly, simple and easy to use.

scholarly journals Cyclic Loading Behaviour of Externally Bonded CFRP Reinforced Concrete Beam-Column Joint

2021 ◽  
pp. 1310-1321
Author(s):  
Harsh N. Bhutwala ◽  
Prof. Vishal B. Patel ◽  
J. D. Rathod ◽  
Prof. A. N. Desai
Keyword(s):  
Cyclic Loading ◽  
Energy Absorption ◽  
Failure Modes ◽  
Reinforced Concrete Beam ◽  
Absorption Capacity ◽  
Rc Beam ◽  
Energy Absorption Capacity ◽  
Externally Bonded ◽  
Column Joint ◽  
Strengthening Technique

Cyclic loading behaviour of RC beam-column joints strengthened with externally bonded Carbon Fiber Reinforced Plastic (CFRP) was analysed through Abaqus CAE software. Effect of the number of CFRP layers and the strengthening technique on failure modes, hysteretic curves, skeleton curves, ductility, and energy dissipation capacity were studied. The results show that the strengthening of RC beam-column joints by externally bonded CFRP can effectively improve the cyclic loading behaviour. Strengthening the joint by fiber bands enhances ductility and energy absorption capacity. The increase in the number of CFRP layers leads to enhance energy absorption capacity significantly as compared to ductility.

Reseach on Flexural Behavior of Reinforced Concrete Beams Strengthened with Prestressed Near Surface Mounted CFRP Tendons

2010 ◽  
Vol 163-167 ◽  
pp. 3537-3544 ◽  
Author(s):  
Ya Hong Ding ◽  
Yan Jie Ma
Keyword(s):  
Reinforced Concrete ◽  
Engineering Application ◽  
Reinforced Concrete Beams ◽  
Flexural Behavior ◽  
Rc Beams ◽  
Near Surface ◽  
Displacement Ductility ◽  
Near Surface Mounted ◽  
Strengthening Technique ◽  
Strengthening Method

The effectiveness of strengthening reinforced concrete (RC) beams with prestressed near- surface mounted (NSM) carbon fiber reinforced polymer (CFRP) rods has been investigated. The RC beams are tested under monotonic loading. The stressing process, failure capacity, flexural capaticy, displacement ductility and deformation are systematically studied. The text results show that the new strengthening technique with prestressed NSM CFRP rods can enhance the first-crack load, steel-yielding load of beams compared to the control beam. It is worth noting that the prestress can limit the crack width all the way up to failure, reduce the midpoint deflection, and improve the service performance of the strengthened beams. The strengthening method offers an alternative way to existing strengthening method. The results provide a reference for engineering application.

scholarly journals Effectiveness of strengthening pre-loaded RC beams with CFRP strips in conventional and accelerated strengthening procedures

2019 ◽  
Vol 284 ◽  
pp. 06005
Author(s):  
Dorota Michałowska-Maziejuk ◽  
Barbara Goszczyńska ◽  
Wiesław Trąmpczyński
Keyword(s):  
Product Information ◽  
Load Capacity ◽  
Concrete Cover ◽  
Reinforced Concrete Beams ◽  
Cross Sectional ◽  
Near Surface ◽  
Near Surface Mounted ◽  
Accepted Practice ◽  
Strengthening Technique ◽  
And Control

This paper analyses the results obtained from the testing of reinforced concrete beams additionally strengthened with composite materials pressed into the concrete cover using the near-surface-mounted reinforcement (NSMR) method. The testing program comprised two series of beams with cross-sectional dimensions of 0.12 x 0.30 x 3.30 m. The series differed in the amount of longitudinal steel reinforcement, 0.51% and 1.00%. Three beams were cast in each series. One beam was assigned as the control beam, while two other beams were strengthened with carbon fibre strips. A two-component thixotropic epoxy resin was used as a bonding agent. One of the two beams was cured for 7 days (to the product information document). The bonding process in the other beam was accelerated to last 1.5 hours by heating the strip up to 70°C. As the strengthening of "new" elements is not an accepted practice in engineering, the beams were pre-loaded. The load was maintained during the strengthening procedure and curing period (for 7 days and 1.5 hours) and then the beams were monotonically loaded to failure. The comparison of load capacity results for the CFRP strengthened and control beams revealed the effectiveness of the strengthening method. The paper also presents the strengthening technique in the NSMR application with the prototype heating device.

scholarly journals Debonding Detection of Reinforced Concrete (RC) Beam with Near-Surface Mounted (NSM) Pre-stressed Carbon Fiber Reinforced Polymer (CFRP) Plates Using Embedded Piezoceramic Smart Aggregates (SAs)

2019 ◽  
Vol 10 (1) ◽  
pp. 50 ◽  
Author(s):  
Yang Liu ◽  
Ming Zhang ◽  
Xinfeng Yin ◽  
Zhou Huang ◽  
Lei Wang
Keyword(s):  
Reinforced Concrete ◽  
Carbon Fiber ◽  
Fiber Reinforced Polymer ◽  
Carbon Fiber Reinforced Polymer ◽  
Rc Beam ◽  
Fiber Reinforced ◽  
Near Surface ◽  
Reinforced Polymer ◽  
Near Surface Mounted ◽  
Carbon Fiber Reinforced

The application of reinforced concrete (RC) beam with near-surface mounted (NSM) pre-stressed carbon fiber reinforced polymer (CFRP) plates has been increasingly widespread in civil engineering. However, debonding failure occurs easily in the early loading stage because of the prestress change at the end of CFRP plate. Therefore, it is important to find reliable, convenient and economical technical means to closely monitor the secure bonding between CFRP and concrete. In this paper, an active sensing approach for generating and sensing stress wave by embedded smart aggregates (SAs) is proposed, which provides a guarantee for the secure connection between CFRP and concrete. Two specimens with different non-pre-stressed bond lengths were fabricated in the laboratory. Six SAs were installed at different positions of the structure to monitor the degree of debonding damage during the loading process. The experiments showed that the optimal length of non-pre-stressed CFRP bond section (300 mm) can significantly improve the load characteristics and enhance the service performance of the structure. The theoretical analysis of wavelet packet shows that increasing the length of non-pre-stressed CFRP bond section can slow down the occurrence and propagation of debonding cracks. The debonding crack in the tension end region is earlier than that in the bond end region. The research results reflect that the developed approach can monitor the damage process caused by debonding cracks and provide early warning for the initial damage and the debonding failure.

scholarly journals Evaluation of a Macro Lump Plasticity Model for Reinforced Concrete Beam-Column Joint under Cyclic Loading

2020 ◽  
Vol 22 (2) ◽  
pp. 82-93
Author(s):  
Joko Purnomo ◽  
V. Octaviani ◽  
P. K. Chiaulina ◽  
Jimmy Chandra
Keyword(s):  
Reinforced Concrete ◽  
Cyclic Loading ◽  
Reinforced Concrete Beam ◽  
Cyclic Behavior ◽  
Rc Beam ◽  
Simple Modification ◽  
Seismic Performance Evaluation ◽  
Spring Element ◽  
Macro Modeling ◽  
Column Joint

Lateral deformations of reinforced concrete (RC) frames under extreme seismic excitation are highly affected by the stiffness of their beam-column joints. Numerous models have been proposed to simulate the responses of RC beam-column joint under cyclic loading. Development of RC beam-column joint model based on macro modeling using spring elements becomes more popular because of its considerably simple application for seismic performance evaluation purposes. In this study, a simple modification to previously developed macro-spring element-based model for RC beam-column joint is done and is used to simulate the behavior of seven external and five internal RC joints under cyclic loading in SAP2000. The model consists of several spring elements to define column, beam, joint, and bond-slip responses according to its individual moment-rotation relationships. Overall, the analysis results show that the modified model can simulate well the cyclic behavior of RC beam-column joints when are compared to previously available experimental results

scholarly journals Influence of Patching on the Shear Failure of Reinforced Concrete Beam without Stirrup

2021 ◽  
Vol 6 (7) ◽  
pp. 97
Author(s):  
Stefanus Adi Kristiawan ◽  
Halwan Alfisa Saifullah ◽  
Agus Supriyadi
Keyword(s):  
Reinforced Concrete ◽  
Shear Failure ◽  
Numerical Study ◽  
Unsaturated Polyester ◽  
Reinforced Concrete Beam ◽  
Concrete Cover ◽  
Shear Capacity ◽  
Rc Beam ◽  
Shear Span ◽  
Shear Cracking

Deteriorated concrete cover, e.g., spalling or delamination, especially when it occurs at the web of a reinforced concrete (RC) beam within the shear span, can reduce the shear capacity of the beam. Patching of this deteriorated area may be the best option to recover the shear capacity of the beam affected. For this purpose, unsaturated polyester resin mortar (UPR mortar) has been formulated. This research aims to investigate the efficacy of UPR mortar in limiting the shear cracking and so restoring the shear capacity of the deteriorated RC beam. The investigation is carried out by an experimental and numerical study. Two types of beams with a size of 150 × 250 × 1000 mm were prepared. The first type of beams was assigned as a normal beam. The other was a beam with a cut off in the non-stirrup shear span, which was eventually patched with UPR mortar. Two reinforcement ratios were assigned for each type of beams. The results show that UPR mortar is effective to hamper the propagation of diagonal cracks leading to increase the shear failure load by 15–20% compared to the reference (normal) beam. The increase of shear strength with the use of UPR mortar is consistently confirmed at various reinforcement ratios.

Sign in / Sign up

Export Citation Format

Share Document