scholarly journals A Model for Shear Strength of FRP Bar Reinforced Concrete Beams without Stirrups

2020 ◽  
Vol 2020 ◽  
pp. 1-9
Author(s):  
Danying Gao ◽  
Changhui Zhang
Keyword(s):  
Shear Strength ◽  
Reinforced Concrete ◽  
Shear Failure ◽  
Concrete Beams ◽  
Reinforced Concrete Beam ◽  
Reinforced Concrete Beams ◽  
Experimental Database ◽  
Proposed Model ◽  
Frp Bar ◽  
Set Up

The shear failure of a reinforced concrete beam generally occurs when the principal tensile stress near the neutral axis is equal to or greater than the tension strength of concrete. In order to set up a model for shear strength for FRP bar reinforced concrete beams without stirrups by the mechanical method, this paper equivalently transformed the FRP bar reinforced concrete rectangular beam with cracks as one composed of ideal elastic material to facilitate the analysis and proposed a new and more reasonable model of shear strength for FRP bar reinforced concrete beams without stirrups. Then, an experimental database including 235 FRP bar reinforced beams without stirrups was compiled to verify the validity of the proposed model. It was found that the values from the proposed model are in better agreement with the experimental results of shear strength of FRP bar reinforced concrete beams without stirrups in comparison with the models in codes.

scholarly journals Shear Strength Prediction Model of FRP Bar-Reinforced Concrete Beams without Stirrups

2020 ◽  
Vol 2020 ◽  
pp. 1-11 ◽  
Author(s):  
Danying Gao ◽  
Changhui Zhang
Keyword(s):  
Shear Strength ◽  
Reinforced Concrete ◽  
Size Effect ◽  
Prediction Model ◽  
Concrete Beams ◽  
Reinforced Concrete Beams ◽  
Strength Prediction ◽  
Longitudinal Reinforcement ◽  
Proposed Model ◽  
Frp Bar

The shear strength prediction model for fiber-reinforced polymer (FRP) bar-reinforced concrete beams without stirrups in ACI440.1R-2015 does not consider the “size effect” and the effect of shear span-to-depth ratio and predicts the zero-shear strength for concrete members without longitudinal reinforcement. A modified shear strength prediction model for FRP bar-reinforced concrete beams without stirrups was presented in this paper. The proposed model takes into account the effect of concrete strength, size of the beam, shear span-to-depth ratio, reinforcement ratio, and modulus of elasticity of the longitudinal reinforcement and the “size effect.” The superiority of the proposed model has been evaluated by comparing the calculated shear strength of FRP bar-reinforced concrete beams without stirrups by the proposed model with the experimental results and calculated values by the models in design codes, respectively. It confirmed that the shear strength of FRP bar-reinforced concrete beams without stirrups by the proposed model was in better agreement with the experimental results.

Implication of Unbondedness in Reinforced Concrete Beams

2012 ◽  
Vol 587 ◽  
pp. 36-41 ◽  
Author(s):  
S.F.A. Rafeeqi ◽  
S.U. Khan ◽  
N.S. Zafar ◽  
T. Ayub
Keyword(s):  
Shear Strength ◽  
Reinforced Concrete ◽  
Failure Mode ◽  
Shear Failure ◽  
Concrete Beams ◽  
Experimental Results ◽  
Reinforced Concrete Beams ◽  
Rc Beams ◽  
Flexural Capacity ◽  
Flexural Reinforcement

In this paper, behaviour of nine (09) RC beams (including two control beams) after unbonding and exposing flexural reinforcement has been studied which were intentionally designed and detailed to observe flexural and shear failure. Beams have been divided into three groups based on failure mode and unbounded and exposed reinforcement. Beams have been tested under two-point loading up to failure. Experimental results are compared in terms of beam behaviour with respect to flexural capacity and failure mode which revealed that the exposed reinforcement does not altered flexural capacity significantly and unbondedness positively influences shear strength; however, serviceability performance of beams with unbonded and exposed reinforcement is less.

SHEAR MECHANISM AND SHEAR STRENGTH PREDICTION OF REINFORCED CONCRETE T-BEAMS

2016 ◽  
Vol 78 (5) ◽  
Author(s):  
Abdul Aziz Abdul Samad ◽  
Noridah Mohamad ◽  
Mohammed Anwar Hail al-Qershi ◽  
J. Jayaprakash ◽  
Priyan Mendis
Keyword(s):  
Shear Strength ◽  
Reinforced Concrete ◽  
Shear Failure ◽  
Reinforced Concrete Beam ◽  
Reinforced Concrete Beams ◽  
Bending Test ◽  
Shear Behaviour ◽  
Design Codes ◽  
Shear Mechanism ◽  
Strength Capacity

Shear failure in reinforced concrete beams are sudden failures and should be avoided at all times. However, the shear behaviour of a reinforced concrete beam is a complex mechanism and requires in-depth study. To understand the shear mechanism, two (2) simply supported reinforced concrete T-beams, BEAM1 and BEAM2 were tested until failure subjected to a 4-point bending test. Both beams were designed to the recommendations and specifications of two (2) established design codes by ACI318-08 and Eurocode2 (EC2). The study comprises of two reinforced concrete T-beams having similar variables and parameters with longitudinal reinforcement of ρ = 2.15% and shear span-to-effective depth ratio (av/d) of 3.5. Shear reinforcement or stirrups has been added to the specimen and its spacing of stirrups has been provided with the provisions of the codes. The findings from the study indicate that ACI318-08 and EC2 design codes shows significant differences in determining its shear strength capacity Vn and concrete shear resistance Vcof the T-beams. However, both results were less conservative in its prediction when compared to the experimental results. 

scholarly journals Shear Strengthening of Reinforced Concrete Beams Using Fibre Reinforced Polymer: A Critical Review

2021 ◽  
Vol 1200 (1) ◽  
pp. 012015
Author(s):  
S J S Hakim ◽  
M A H Mohd Rodzi ◽  
S S Ayop ◽  
S Shahidan ◽  
S N Mokhatar ◽  
...  
Keyword(s):  
Shear Strength ◽  
Reinforced Concrete ◽  
Concrete Beams ◽  
High Strength ◽  
Reinforced Concrete Beam ◽  
Reinforced Concrete Beams ◽  
Ultimate Shear Strength ◽  
Shear Strengthening ◽  
Reinforcing Bar ◽  
Fibre Reinforced Polymer

Abstract The primary purpose of reinforcing bar stirrups in a reinforced concrete beam is to improve shear strength. The FRP system may significantly improve a concrete beam’s ultimate shear strength, serviceability, and ductility. The application of FRP for the repair and reinforcement of the structures has become very popular due to its low weight, high tensile strength, and simplicity of installation on uneven surfaces. FRP material outperforms other traditional materials in strengthening applications due to its high strength-to-weight and stiffness-to-weight ratios, resistance to corrosion, and ease of handling. The overall objective of this research is to investigate and improve the understanding of the recent research in the area of shear FRP strengthening of reinforced concrete beams. In this paper, recent publications were reviewed to see how different anchoring procedures, different factors that affect FRP performance and different failure scenarios affect the shear strengthening of concrete beams. The benefits and limits of FRP systems, as well as some current research trends are discussed in this project. From the research, it can be stated that type of anchorage technique and different parameter give a different impact to failure mode of the beam.

scholarly journals Crack Detection of FRP-Reinforced Concrete Beam Using Embedded Piezoceramic Smart Aggregates

Sensors ◽  
2019 ◽  
Vol 19 (9) ◽  
pp. 1979 ◽  
Author(s):  
Tianyong Jiang ◽  
Yue Hong ◽  
Junbo Zheng ◽  
Lei Wang ◽  
Haichang Gu
Keyword(s):  
Reinforced Concrete ◽  
Stress Wave ◽  
Concrete Beam ◽  
Concrete Beams ◽  
Reinforced Concrete Beam ◽  
Reinforced Concrete Beams ◽  
The Other ◽  
Experimental Program ◽  
Active Sensing ◽  
Frp Bar

In this paper, the authors present a stress wave-based active sensing method to detect the crack in FRP-reinforced concrete beams. The embedded smart aggregates (SAs), which utilize Lead Zirconate Titanate (PZT) as transducers, are employed in this research to generate and sense the stress wave. Three specimens are involved in the experimental program and each is made of concrete, longitudinal distributed reinforcement, steel stirrups, main bar (FRP bar or steel bar), and four SAs. A pair of SAs installed on the lower part of the main bar and the other pair of SAs mounted on the upper part of main bar are utilized to monitor the crack occurrence and development in the three test specimens. The signals received by the SA sensors are analyzed in both time domain and frequency domain. The wavelet packet energy is used to extract damage features. The applied load–vertical displacement curves of mid-span in the specimen are obtained. Experimental results show the test specimens experience crushing failure when the concrete compression exceeds its compressive strength. Increasing the contact area between FRP bar and concrete can effectively improve the cracking load of the FRP-reinforced concrete beam and reduce the cracking speed and depth of FRP-reinforced concrete beam; on the other hand, increasing the elastic modulus of the main bar can slow down the crack development of concrete on the upper side of the main bar and decrease the displacement of reinforced concrete beam during the loading test process. The research results show that the developed piezoceramic-based active sensing method, though low-cost, can monitor the crack-induced damage and estimate the process of damage degree in real-time, and has potentials to provide an early warning of crack occurrence and development for FRP-reinforced concrete beams.

Influence of the Reinforcement’s Number on the Mechanical Properties of the Reinforced Concrete Beam

2010 ◽  
Vol 105-106 ◽  
pp. 723-728 ◽  
Author(s):  
Wei Hong Li ◽  
Xue Yang
Keyword(s):  
Reinforced Concrete ◽  
Concrete Beam ◽  
Concrete Beams ◽  
Process Analysis ◽  
Failure Process ◽  
Reinforced Concrete Beam ◽  
Reinforced Concrete Beams ◽  
Practical Significance ◽  
Gradual Failure ◽  
Set Up

Basing on the experimental data collected, the mechanical model of reinforced concrete beams’ gradual failure has been set up, to test differ reinforced components with loads and study the process of split. At last the influence of reinforcement’s number on components’ intensity and failure process are analyzed by using MFPA2D (Material Failure Process Analysis) software, started with the analysis of formula cracks after experiments. The results showed that the number of reinforcement is not the more the better. When ultra-reinforced beam appears, its mechanical capacity enhances but the bars won’t do their best, furthermore, it is uneconomical. Accordingly, less-reinforced beam should also be avoided for safe. Everything possible should be made to avoid ultra-reinforced beam and less-reinforced beam in engineering. By all means, this conclusion has practical significance during our practice.

Reinforced concrete beams without stirrups considering shear friction and fracture mechanics

2006 ◽  
Vol 33 (2) ◽  
pp. 161-168 ◽  
Author(s):  
M T Kazemi ◽  
V Broujerdian
Keyword(s):  
Shear Strength ◽  
Reinforced Concrete ◽  
Fracture Mechanics ◽  
Shear Failure ◽  
Concrete Beams ◽  
Concrete Strength ◽  
Shear Capacity ◽  
Reinforced Concrete Beams ◽  
Maximum Aggregate Size ◽  
Aggregate Interlock

A new expression for the shear capacity of reinforced concrete beams without stirrups was derived by calculating the aggregate interlock capacity across the major diagonal crack of the beam, a procedure somewhat similar to those based on the modified compression field theory. Two formulas were obtained from the simplification of this expression. All three relations capture the dependence of shear strength on the size of the beam, the ratio of shear span to beam depth, longitudinal reinforcement ratio, maximum aggregate size, and concrete strength. The limits of these formulas agree well with the limit solutions of shear failure load for very small and very large beams based on plastic and fracture mechanics solutions, respectively. The proposed relations were calibrated by least-squares fitting of the existing experimental database (consisting of 398 data points) and resulted in low coefficients of variation. The simplest version is suitable for design codes.Key words: reinforced concrete, shear strength, beams, aggregate interlock, crack opening, size effect.

Behaviour of reinforced concrete beam strengthened in shear with geosynthetic

2020 ◽  
Vol 23 (9) ◽  
pp. 1851-1864 ◽  
Author(s):  
Subhrasmita Majumder ◽  
Showmen Saha
Keyword(s):  
Reinforced Concrete ◽  
Shear Failure ◽  
Concrete Beams ◽  
Single Point ◽  
Reinforced Concrete Beam ◽  
Primary Objective ◽  
Absorption Capacity ◽  
Shear Capacity ◽  
Reinforced Concrete Beams ◽  
Experimental Findings

The primary objective of this article is to focus on the experimental investigation of shear-deficient and geosynthetic-strengthened reinforced concrete beams. In this study, two varieties of geosynthetic, namely geogrid and geotextile, are used. The performances of shear-deficient reinforced concrete beams strengthened with geosynthetics under the single-point static monotonic loading are studied. It is observed that shear failure occurs in shear-deficient beam, but after strengthening the brittle shear failure changes to ductile flexure failure. A significant increment in flexural strength, ductility, energy absorption capacity and inelastic performance is observed in strengthened beams. The performance of geogrid is better in all respects when compared to the geotextile. The test results reveal that the use of geosynthetic not only increases the shear capacity but also remarkably improves the ductile behaviour of RC beams. In addition, conventional analytical methods are applied for the evaluation of the ultimate load, and the results are compared with the experimental findings, which show a good agreement between the analytical and experimental results.

Study on Shear Resistance and Durability of CFRP Reinforced Concrete Beams

2013 ◽  
Vol 351-352 ◽  
pp. 1714-1717
Author(s):  
Shuang Chen
Keyword(s):  
Reinforced Concrete ◽  
Concrete Beam ◽  
Shear Failure ◽  
Concrete Beams ◽  
Shear Resistance ◽  
Reinforced Concrete Beam ◽  
Reinforced Concrete Beams ◽  
Test Beam ◽  
Shear Bearing Capacity ◽  
Chlorine Ion

Through carrying capacity test of CFRP strengthened test beam and unstrengthened comparison beam under corrosion of chlorine ion, thispaper analyzes the shear resistance and durability of CFRP repaired and strengthened concrete beam. Crack generation, deflection, electrochemical index and deformation of reinforced concrete beam under service are comparedand analyzed. It is indicated that CFRP can play a favorable screening role and can effectively prevent crack development. There is no shear failure after load is applied. So CFRP can obviously improve the shear bearing capacity and durability of reinforced concrete beam. Besides, different strengthening methods have relatively obvious influence of its durability.

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