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.

Static and Fatigue Experimental Research on Reinforced Concrete Beams Strengthened with Pre-Stress CFRP Rods

2011 ◽  
Vol 368-373 ◽  
pp. 2001-2005
Author(s):  
Li Hua Xu ◽  
Hao Zeng ◽  
Feng Xu ◽  
Wen Ke Qin
Keyword(s):  
Reinforced Concrete ◽  
Fatigue Life ◽  
Concrete Beams ◽  
Fatigue Behavior ◽  
Reinforced Concrete Beams ◽  
Fatigue Performance ◽  
Stress Range ◽  
Reinforcing Bars ◽  
Flexural Capacity ◽  
Novel Technique

In this paper, a total of six reinforced concrete beams including four beams strengthened with externally prestressed CFRP rods and two unstrengthened beams have been tested under monotonic and cylic loads in order to investigate the influence of a novel technique on the flexural static and fatigue behavior of the specimens. The experimental results show that the static and fatigue performance of strengthened members have been improved in terms of that the flexural capacity is greatly enhanced, the fatigue life is increased and the stress range of the internally tensile reinforcing bars is decreased as compared with the unstrengthened ones. It indicates that the developed technique can enhance the flexural capacity as well as improve the fatigue performance of RC members.

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.

A prototype knowledge-based expert system for the design and detailing of reinforced concrete beams

1991 ◽  
Vol 18 (6) ◽  
pp. 1005-1012
Author(s):  
George Akhras ◽  
John A. Fedoruk
Keyword(s):  
Reinforced Concrete ◽  
Expert System ◽  
Concrete Beam ◽  
Concrete Beams ◽  
Load Capacity ◽  
Reinforced Concrete Beam ◽  
Reinforced Concrete Beams ◽  
Graphical Form ◽  
Knowledge Based ◽  
Beam Design

Most computer programs developed for reinforced concrete beam design either analyze a given cross section for load capacity or offer a limited solution from which the engineer must continue toward the final design. These programs are very useful in performing many tedious calculations. However, they generally do not offer assistance in areas of design that require intuitive reasoning, experiential knowledge, rules of thumb, and sound engineering judgement. This type of heuristic knowledge has been incorporated into a prototype knowledge-based expert system for reinforced concrete beam design and detailing called BeamEx. BeamEx interacts with the user to advise and establish suitable parameters required for the comprehensive design of rectangular simply supported and continuous beams. It incorporates heuristic rules drawn from the governing Canadian codes and textbooks to design alternative suitable beams which are presented in graphical form. It is shown that a knowledge-based system approach can be used effectively in engineering design by encapsulating domain expertise in a program to complement and check the experience of the users in design. Key words: knowledge-based expert system, reinforced concrete, beams, design, detailing.

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 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.

scholarly journals Research on the Efficiency of Composite Beam Application in Multi-Storey Buildings

2020 ◽  
Vol 12 (20) ◽  
pp. 8328 ◽  
Author(s):  
Tomas Kinderis ◽  
Mindaugas Daukšys ◽  
Jūratė Mockienė
Keyword(s):  
Reinforced Concrete ◽  
Fire Resistance ◽  
Composite Beam ◽  
Concrete Beams ◽  
Residential Building ◽  
Reinforced Concrete Beam ◽  
Composite Beams ◽  
Reinforced Concrete Beams ◽  
Assessment Criteria ◽  
Floor Structure

Over the past decade, several types of composite slim floor constructions have been used in multi-storey buildings in Lithuania. In order to study the efficiency of composite beam application in steel-framed multi-storey buildings, Thorbeam (A1), Deltabeam (A2), slim floor beam (A3) and asymmetric slim floor beam (A4) were chosen and evaluated according to nine assessment criteria (beam cost (K1), initial preparation on site (K2), installation time (K3), complexity of installation technology (K4), labour costs (K5), fire resistance (K6), load bearing capacity (K7), beam versatility (K8), and availability of beams (K9)). First, the significance of the rating criteria was selected and the order of the ranking criteria was obtained (K1˃K7˃K3˃K6˃K4˃K5˃K2˃K8˃K9) by means of a survey questionnaire. Second, the beams were ranked according to the points given by the questionnaire respondents as follows: 160 points were given to A2, 144 points to A1, 129 points to A4, and 111 points to A3. Deltabeam is considered to be the most rational alternative of the four beams compared. Calculations done using the Technique for Order Preference by Similarity to an Ideal Solution (TOPSIS) analysis method revealed that composite beam A2 was the best slim floor structure alternative for an eight-storey high-rise commercial residential building frame, A1 ranked second, A4 ranked third, and A3 ranked fourth. In addition, the four composite beams were compared to a reinforced concrete beam (A5) according to three assessment criteria (beam cost including installation (C1), beam self-weight (C2) and fire resistance (C3)). Deltabeam was found to be efficient for use as a slim floor structure in a multi-story building due to having the lowest cost, including installation, and self-weight, and the highest fire resistance compared to other composite beams studied. Although Deltabeams are 1.4 times more expensive than reinforced concrete beams, including installation costs, they save about 2.5% of the building’s height compared to reinforced concrete beams.

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