scholarly journals Low-Cycle Flexural Fatigue Behavior of Concrete Beam Reinforced with Hybrid FRP-Steel Rebar

2018 ◽  
Vol 2018 ◽  
pp. 1-13 ◽  
Author(s):  
Jinkyo F. Choo ◽  
Young-Cheol Choi ◽  
Seung-Jun Kwon ◽  
Ki-Tae Park ◽  
Sung-Won Yoo
Keyword(s):  
Reinforced Concrete ◽  
Cyclic Loading ◽  
Concrete Beam ◽  
Concrete Beams ◽  
Fatigue Behavior ◽  
Reinforced Concrete Beam ◽  
Flexural Behavior ◽  
Fatigue Cycle ◽  
Flexural Fatigue ◽  
Steel Rebar

Studies examined experimentally the flexural behavior of concrete beams reinforced with the hybrid FRP-steel rebar but very few among them evaluated their fatigue performance. In this study, the fatigue test has been performed, and an analytical model for simulating the flexural fatigue behavior of the concrete beam reinforced with the hybrid bar considering its postyielding behavior is developed. A formula relating the postyielding fatigue strain of the rebar to the number of the fatigue cycle is suggested and used in the proposed procedure. The method simulating the low-cycle behavior of the reinforced concrete beam is found to be satisfactory and can predict the number of cyclic loading to failure.

scholarly journals Flexural Behavior of Bamboo Reinforced Concrete Beam with Steel Stirrups

2019 ◽  
Vol 8 (4S2) ◽  
pp. 97-99
Keyword(s):  
Reinforced Concrete ◽  
Concrete Beam ◽  
Concrete Beams ◽  
Reinforced Concrete Beam ◽  
Flexural Behavior ◽  
Test Results ◽  
Steel Reinforced Concrete ◽  
Beam Design ◽  
Materials Used ◽  
Bamboo Reinforcement

The flexural behavior of concrete beams reinforced with bamboo was studied experimentally. Bamboo was used as the main reinforcement with different bonding materials in place of steel. A nominal mix of M20 grade concrete was adopted for the beam design. The Bamboo surface was treated with common binding materials like Araldite and Bitumen. Araldite and Bitumen are good binding materials used to connect materials like steel, carbon and many different materials. Two specimens were casted with bitumen coating, two specimens were coated with araldite, two specimens were casted without any binder coating and a specimen was casted using normal steel reinforcement. Beams were casted with bamboo reinforcement and cured for 28 days. Deflection and flexural behavior of the beams were monitored. The test results imply that araldite coating in concrete beams with bamboo reinforcement increased the flexural strength to that of bamboo reinforced concrete using bitumen which is lesser strength to that of steel reinforced concrete beam.

Experimental Study on Flexural Behavior of Damaged Reinforced Concrete Beams Strengthened with CFRP

2014 ◽  
Vol 507 ◽  
pp. 306-310 ◽  
Author(s):  
Bin Jia ◽  
Jin Xue ◽  
Jun Mo ◽  
Chun Tao Zhang
Keyword(s):  
Reinforced Concrete ◽  
Concrete Beam ◽  
Concrete Beams ◽  
Concrete Strength ◽  
High Strength ◽  
Reinforced Concrete Beam ◽  
Reinforced Concrete Beams ◽  
Flexural Behavior ◽  
Failure Model ◽  
High Coherence

Abstract. In the view of the project problem that concrete strength grade is lower than C15in reinforced concrete beam, we consider a composite technology strengthened with CFRP, and do some monotonic loading experiments on these beams with eight different methods, and discuss the beam force behavior including ultimate bearing capacity, failure model and crack propagation. This paper finds out that the composite reinforced scheme, which with ticking trough, planting steel displaces concrete and gluing and then pasting CFRP, has a remarkable improvement than pasting CFRP immediately, and that there is a high coherence workability in the old and new concrete, so we can give full play to their role as the CFRP high strength.

scholarly journals Study on equivalent static method for the analysis of fatigue behavior of reinforced concrete beam

2021 ◽  
Vol 272 ◽  
pp. 02018
Author(s):  
Fangping Liu ◽  
Chen Yu ◽  
Wentao Yi
Keyword(s):  
Numerical Simulation ◽  
Reinforced Concrete ◽  
Concrete Beam ◽  
Static Load ◽  
Concrete Beams ◽  
Fatigue Behavior ◽  
Reinforced Concrete Beam ◽  
Static Method ◽  
Reinforced Concrete Beams ◽  
Simulation Results

In order to analyze the whole process of fatigue behaviours of reinforced concrete beams, an equivalent static analysis method is proposed in this paper. Firstly, the constitutive models based on the degradation of stiffness and strength and the accumulation of residual strain of concrete and reinforcement subjected to fatigue loadings are deduced and established by coupling the uniaxial constitutive model of concrete and the ideal elastic-plastic model of reinforcement under static load. Secondly, based on the similarity of concrete failure under static load and fatigue load, the equivalent relationship between fatigue and static analysis can be constructed by using the concrete residual strain as the equivalent parameter. On this basis, an equivalent static method for the analysis of fatigue behavior of reinforced concrete beam is proposed. At last, three reinforced concrete beams with rectangular section are tested, and the fatigue behaviours are analyzed by the method proposed in this paper. The numerical simulation results are compared with the field test data. The result shows that the numerical simulation results are in good agreement with the experimental results, which verifies the reliability and practicability of the method.

scholarly journals The Effect of Steel Plate on the Deflection of Self Reinforced Concrete Beam with and Without Opening

2013 ◽  
Vol 6 (1) ◽  
pp. 36-49
Author(s):  
Ali Sabah AL-Amili
Keyword(s):  
Reinforced Concrete ◽  
Concrete Beam ◽  
Steel Plate ◽  
Failure Load ◽  
Concrete Beams ◽  
Reinforced Concrete Beam ◽  
Reinforced Concrete Beams ◽  
Steel Plates ◽  
Flexural Behavior ◽  
External Plate

In this work aims at studying the influence of steel plate on the deflection of self- compacted reinforced concrete beams was investigated experimentally in this study to know the flexural behavior of these beams. Eight simply supported reinforced concrete beam were tested under the action of two point loads .The deflections of the beams with and without plate are measured. The steel plates of thickness (3 mm) with dimensions ( 170 × 350 mm) were used. These plates were sticked on the concrete beams using epoxy. The steel plate inside the beam was sticked with and without epoxy (epoxy type EP), while the beams were taken with and without opening (10 mm diameter). The results show that the plate increased the capacity of the beam by increased the value of failure load. Hence, the beam with internal plate with epoxy increased the failure load by 34.2% than beam without plate , and 24.6% than beam with internal plate without epoxy , and 19.7% than beam with external plate with epoxy .

scholarly journals Fatigue Flexural Performance of Short-Span Reinforced Concrete T-Beams Considering Overloading Effect

2020 ◽  
Vol 15 (2) ◽  
pp. 89-110
Author(s):  
Chenxu Zhuang ◽  
Jinquan Zhang ◽  
Ruinian Jiang
Keyword(s):  
Reinforced Concrete ◽  
Fatigue Life ◽  
Cyclic Loading ◽  
Concrete Beams ◽  
Fatigue Behavior ◽  
Reinforced Concrete Beam ◽  
Reinforced Concrete Beams ◽  
Reinforcing Bars ◽  
Beam Design ◽  
Short Span

Traffic volume increase and higher proportion of heavier trucks have raised the potential risk of fatigue failure of short-span reinforced concrete beams. To investigate the fatigue behavior of short-span reinforced concrete beams with and without the overload effect, nine 5 m reinforced concrete T-beams were cast and tested. Two beams were tested under static loading to determine the ultimate strength; the remaining seven beams were subjected to cyclic loading with constant-amplitude load ranges. In addition, two of the seven beams were subjected to instant overloading. It was observed that the typical failure mode under cyclic loading was the fatigue fracture of tensile reinforcing bars. The introduction of instant overloading resulted in a remarkable reduction of fatigue life. Among all the parameters, the stress range of the reinforcing bars showed the highest effect on the fatigue life. In the end, the fatigue safety provisions in the current reinforced concrete beam design codes were evaluated based on the fatigue limits and S-N curves.

Application of Fly Ash-Based Geopolymer for Structural Member and Repair Materials

2014 ◽  
Vol 92 ◽  
pp. 74-83 ◽  
Author(s):  
Wanchai Yodsudjai
Keyword(s):  
Reinforced Concrete ◽  
Fly Ash ◽  
Concrete Beam ◽  
Setting Time ◽  
Reinforced Concrete Beam ◽  
Structural Member ◽  
Steel Reinforcement ◽  
Flexural Behavior ◽  
Fundamental Properties ◽  
Repair Materials

The applications of using fly ash-based geopolymer as a structural member and a repair materials in reinforced concrete structure was conducted. The optimum mix proportion of fly ash-based geopolymer concrete using for structural beam and fly ash-based geopolymer mortar using for repair material were developed. The flexural behavior of fly ash-based geopolymer reinforced concrete and the durability aspect namely the corrosion of steel reinforcement were investigated using the electrical acceleration. For the repair purpose, the fundamental properties; that is, compressive strength, flexural strength, bonding strength between fly ash-based geopolymer mortar and mortar substrate, setting time and chloride penetration were investigated. Also, the durability of conventional reinforced concrete beam repaired by the fly ash-based geopolymer mortar comparing with the comercial repair mortar was investigated. The behavior of the fly ash-based geopolymer reinforced concrete beam was similar to that of the conventional reinforced concrete beam; however, the corrosion of the steel reinforcement of the fly ash-based geopolymer reinforced concrete beam was higher than that of the conventional reinforced concrete beam. The fundamental properties of the fly ash-based geopolymer mortar were not different from that of the commercial repair materials; however, the durability of the reinforced concrete beam repaired by the fly ash-based geopolymer mortars performed a little lower than that of repaired with the commercial repair motar and also the control reinforced concrete with no repair. As a result, even there will be still a need of improvement there was a good tendency for using the fly ash-based geopolymer as the structural member and the repair materials.

scholarly journals Influence of steel–concrete bond damage on the dynamic stiffness of cracked reinforced concrete beams

2018 ◽  
Vol 21 (13) ◽  
pp. 1977-1989 ◽  
Author(s):  
Tengfei Xu ◽  
Jiantao Huang ◽  
Arnaud Castel ◽  
Renda Zhao ◽  
Cheng Yang
Keyword(s):  
Reinforced Concrete ◽  
Concrete Beam ◽  
Natural Frequencies ◽  
Concrete Beams ◽  
Dynamic Stiffness ◽  
Reinforced Concrete Beam ◽  
Reinforced Concrete Beams ◽  
Reinforcing Bar ◽  
Sustained Loading ◽  
Inertia Model

In this article, experiments focusing at the influence of steel–concrete bond damage on the dynamic stiffness of cracked reinforced concrete beams are reported. In these experiments, the bond between concrete and reinforcing bar was damaged using appreciate flexural loads. The static stiffness of cracked reinforced concrete beam was assessed using the measured load–deflection response under cycles of loading and unloading, and the dynamic stiffness was analyzed using the measured natural frequencies with and without sustained loading. Average moment of inertia model (Castel et al. model) for cracked reinforced beams by taking into account the respective effect of bending cracks (primary cracks) and the steel–concrete bond damage (interfacial microcracks) was adopted to calculate the static load–deflection response and the natural frequencies of the tested beams. The experimental results and the comparison between measured and calculated natural frequencies show that localized steel–concrete bond damage does not influence remarkably the dynamic stiffness and the natural frequencies both with and without sustained loading applied. Castel et al. model can be used to calculate the dynamic stiffness of cracked reinforced concrete beam by neglecting the effect of interfacial microcracks.

Prediction Scheme of Torsional Strength of Reinforced Concrete Beam

2012 ◽  
Vol 214 ◽  
pp. 306-310
Author(s):  
Han Chen Huang
Keyword(s):  
Genetic Algorithm ◽  
Reinforced Concrete ◽  
Concrete Beam ◽  
Concrete Beams ◽  
Reinforced Concrete Beam ◽  
Reinforced Concrete Beams ◽  
Ann Model ◽  
Torsional Strength ◽  
Prediction Scheme ◽  
Optimal Network

This study proposes a artificial neural network with genetic algorithm (GA-ANN) for predicting the torsional strength of reinforced concrete beam. Genetic algorithm is used to the optimal network structure and parameters. A database of the torsional failure of reinforced concrete beams with a rectangular section subjected to pure torsion was obtained from existing literature for analysis. This study compare the predictions of the GA-ANN model with the ACI 318 code used for analyzing the torsional strength of reinforced concrete beam. The results show that the proposed model provides reasonable predictions of the ultimate torsional strength of reinforced concrete beams and offers superior torsion accuracy compared to that of the ACI 318-89 equation.

Uniform loading on the reinforced concrete beam produced by the specific cylinder-shaped rubber bags fully filled with air or water

2020 ◽  
Vol 23 (9) ◽  
pp. 1934-1947
Author(s):  
Dapeng Chen ◽  
Li Chen ◽  
Qin Fang ◽  
Yuzhou Zheng ◽  
Teng Pan
Keyword(s):  
Finite Element ◽  
Reinforced Concrete ◽  
Finite Element Model ◽  
Concrete Beam ◽  
Concrete Beams ◽  
Element Model ◽  
Reinforced Concrete Beam ◽  
Reinforced Concrete Beams ◽  
Uniform Loading ◽  
Air Bag

The bending behavior of reinforced concrete beams under uniform pressure is critical for the research of the blast-resistance performance of structural components under explosive loads. In this study, a bending test of five reinforced concrete beams with the dimensions of 200 mm (width) × 200 mm (depth) × 2500 mm (length) under uniform load produced by a specific cylinder-shaped rubber bag filled with air or water was conducted to investigate their flexural performances. An air bag load was applied to three of the reinforced concrete beams, a water bag load was applied to one reinforced concrete beam, and the remainder beam was subjected to the 4-point bending load. The experimental results highlighted that the air bag and water bag loading methods can be used to effectively apply uniform loads to reinforced concrete beams. Moreover, the stiffness of the air bag was improved by 123% in accordance with the initial pressure increases from 0.15 to 0.45 MPa. In addition, a finite element model of the test loading system was established using ABAQUS/Standard software. Moreover, the critical factors of the air bag loading method were analyzed using the numerical model. The calculated results were found to be in good agreement with the test data. The established finite element model can therefore be used to accurately simulate the action performances of the uniform loading technique using rubber bags filled with air or water.

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