scholarly journals Fatigue Crack Inspection and Acoustic Emission Characteristics of Precast RC Beam under Repetition Loading

2015 ◽  
Vol 773-774 ◽  
pp. 1022-1026 ◽  
Author(s):  
Md Noor Noorsuhada ◽  
Ibrahim Azmi ◽  
Muhamad Bunnori Norazura ◽  
Mohd Saman Hamidah ◽  
Mat Saliah Soffian Noor ◽  
...  
Keyword(s):  
Acoustic Emission ◽  
Fatigue Crack ◽  
Reinforced Concrete ◽  
Concrete Beam ◽  
Concrete Beams ◽  
Signal Strength ◽  
Fatigue Loading ◽  
Reinforced Concrete Beam ◽  
Crack Pattern ◽  
Reinforced Concrete Beams

Fatigue crack of the precast reinforced concrete beam under repetition loading is vital to be examined. Reinforced concrete structures exposed to excessive repetition loading could lead to the failure of the structures. In order to examine the active fatigue crack, the reinforced concrete beams were subjected to three-point repetition maximum loading. Eight phases of maximum fatigue loading with sinusoidal wave, frequency of 1 Hz and 5000 cycles for each phase were performed on the reinforced concrete beams. The inspection was carried out with visual observation of the crack pattern and acoustic emission technique for each load phase. The signal strength of acoustic emission was investigated. It is found that the signal strength of acoustic emission and crack pattern of the reinforced concrete beam subjected to repetition loadings showed promising results for structural health monitoring.

Testing Research for Deformation and Rigidity of Lightweight Aggregate Reinforced Concrete Beams under Fatigue Loading

2012 ◽  
Vol 204-208 ◽  
pp. 3123-3127
Author(s):  
Guang Yu Lei ◽  
Chang Hong Wu ◽  
Shi Ming Li
Keyword(s):  
Reinforced Concrete ◽  
Static Loading ◽  
Concrete Beam ◽  
Concrete Beams ◽  
Lightweight Aggregate ◽  
Fatigue Loading ◽  
Reinforced Concrete Beam ◽  
Reinforced Concrete Beams

Through the experiment of eight lightweight aggregate reinforced concrete beams under static loading and fatigue loading with constant amplitudes, the deformation rule under fatigue loading was analysed, the rigidity calculation means and formulations of lightweight aggregate reinforced concrete beam under fatigue loading were also discussed.

Application of acoustic emission monitoring for assessment of bond performance of corroded reinforced concrete beams

2016 ◽  
Vol 16 (6) ◽  
pp. 732-744 ◽  
Author(s):  
Ahmed A Abouhussien ◽  
Assem AA Hassan
Keyword(s):  
Acoustic Emission ◽  
Reinforced Concrete ◽  
Concrete Beams ◽  
Signal Strength ◽  
Point Load ◽  
Reinforced Concrete Beams ◽  
Bond Failure ◽  
Acoustic Emission Monitoring ◽  
Bond Performance ◽  
Emission Monitoring

This article presents the results of an experimental investigation on the application of acoustic emission monitoring for the evaluation of bond behaviour of deteriorated reinforced concrete beams. Five reinforced concrete beam–anchorage specimens designed to undergo bond failure were exposed to corrosion at one of the anchorage zones by accelerated corrosion. Two additional beams without exposure to corrosion were included as reference specimens. The corroded beams were subjected to four variable periods of corrosion, leading to four levels of steel mass loss (5%, 10%, 20% and 30%). After these corrosion periods, all seven beams were tested to assess their bond performance using a four-point load setup. The beams were continuously monitored by attached acoustic emission sensors throughout the four-point load test until bond failure. The analysis of acquired acoustic emission signals from bond testing was performed to detect early stages of bond damage. Further analysis was executed on signal strength of acoustic emission signals, which used cumulative signal strength, historic index ( H( t)) and severity ( Sr) to characterize the bond degradation in all beams. This analysis allowed early identification of three stages of damage, namely, first crack, initial slip and anchorage cracking, before their visual observation, irrespective of corrosion level or sensor location. Higher corrosion levels yielded significant reduction in both bond strength and corresponding acoustic emission parameters. The results of acoustic emission parameters ( H( t) and Sr) enabled the development of a damage classification chart to identify different stages of bond deterioration.

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.

Numerical Analysis of Reinforced Concrete Beam Strengthened with CFRP or GFRP Laminates

2016 ◽  
Vol 707 ◽  
pp. 51-59 ◽  
Author(s):  
Osama Ahmed Mohamed ◽  
Rania Khattab
Keyword(s):  
Reinforced Concrete ◽  
Concrete Beam ◽  
Ultimate Load ◽  
Concrete Beams ◽  
Reinforced Concrete Beam ◽  
Reinforced Concrete Beams ◽  
Fiber Reinforced Polymer ◽  
Fiber Reinforced ◽  
Reinforced Polymer ◽  
Glass Fiber Reinforced

The behaviour of reinforced concrete beam strengthened with Carbon Fiber Reinforced Polymer (CFRP) and Glass fiber reinforced polymer GFRP laminates was investigated using finite element models and the results are presented in this paper. The numerical investigation assessed the effect of the configuration of FRP strengthening laminates on the behaviour of concrete beams. The load-deflection behaviour, and ultimate load of strengthened beam were compared to those of un-strengthened concrete beams. It was shown that using U-shaped FRP sheets increased the ultimate load. The stiffness of the strengthed beam also increased after first yielding of steel reinforcing bars. At was also observed that strengthening beams with FRP laminates to one-fourth of the beam span, modifies the failure of the beam from shear-controlled near the end of the unstrengthened beam, to flexure-controlled near mid-span. CFRP produced better results compared GFRP in terms of the ability to enhance the behavior of strengthenened reinforced concrete beams.

scholarly journals Study on the Flexural Performance of Hybrid-Reinforced Concrete Beams with a New Cathodic Protection System Subjected to Corrosion

Materials ◽  
2020 ◽  
Vol 13 (1) ◽  
pp. 234 ◽  
Author(s):  
Yingwu Zhou ◽  
Yaowei Zheng ◽  
Lili Sui ◽  
Biao Hu ◽  
Xiaoxu Huang
Keyword(s):  
Reinforced Concrete ◽  
Concrete Beam ◽  
Concrete Beams ◽  
Steel Corrosion ◽  
Reinforced Concrete Beam ◽  
Reinforced Concrete Beams ◽  
Fiber Reinforced Polymer ◽  
Flexural Performance ◽  
Reinforced Polymer ◽  
Steel Bar

Steel corrosion is considered as the main factor for the insufficient durability of concrete structures, especially in the marine environment. In this paper, to further inhibit steel corrosion in a high chloride environment and take advantage of the dual-functional carbon fiber reinforced polymer (CFRP), the impressed current cathodic protection (ICCP) technique was applied to the hybrid-reinforced concrete beam with internally embedded CFRP bars and steel fiber reinforced polymer composite bar (SFCB) as the anode material while the steel bar was compelled to the cathode. The effect of the new ICCP system on the flexural performance of the hybrid-reinforced concrete beam subjected to corrosion was verified experimentally. First, the electricity-accelerated precorrosion test was performed for the steel bar in the hybrid-reinforced beams with a target corrosion ratio of 5%. Then, the dry–wet cycles corrosion was conducted and the ICCP system was activated simultaneously for the hybrid-reinforced concrete beam for 180 days. Finally, the three-point bending experiment was carried out for the hybrid-reinforced concrete beams. The steel bars were taken out from the concrete to quantitatively measure the corrosion ratio after flexural tests. Results showed that the further corrosion of steel bars could be inhibited effectively by the ICCP treatment with the CFRP bar and the SFCB as the anode. Additionally, the ICCP system showed an obvious effect on the flexural behavior of the hybrid-reinforced concrete beams: The crack load and ultimate load, as well as the stiffness, were enhanced notably compared with the beam without ICCP treatment. Compared with the SFCB anode, the ICCP system with the CFRP bar as the anode material was more effective for the hybrid-reinforced concrete beam to prevent the steel corrosion.

THE REINFORCED CONCRETE BEAM DEFLECTION AND CRACKING BEHAVIOR WITH ADDITIONAL FIBER STEEL

2017 ◽  
Vol 4 (1) ◽  
Author(s):  
Faisal Ananda ◽  
Agoes Soehardjono ◽  
Achfas Zacoeb ◽  
Gunawan Saroji
Keyword(s):  
Tensile Strength ◽  
Reinforced Concrete ◽  
Crack Width ◽  
Concrete Beam ◽  
Concrete Beams ◽  
Reinforced Concrete Beam ◽  
Reinforced Concrete Beams ◽  
Beam Deflection ◽  
Cracking Behavior ◽  
Classic Theory

The classic theory mentions that the assessment of deflection and crack width should be taken to minimize those two behaviors. This research itself has the objective to examine whether the additional fiber steel and increased reinforcement ratio has any significant impact on the deflection and existing crack width. This test used the reinforced concrete beams with a size of 15 cm x 25 cm x 180 cm which placed on a simple pedestal. The test was done gradually in every 108 kg until the reinforced yield reached. The fiber increased from 0%, 1.57%, 3.14% and 4.71% while the performance rebar ratio increased from 2 # 10, 2 # 12, and 2 # 14. The result shows that additional 4.71% of maximum fiber decrease compressive strength and rupture modulus while the tensile strength increased. The additional fiber reached a maximum in 4.71% and the additional diameter of 10 mm, 12 mm, and 14 mm increased the deflections and crack width.

Experiment on the Crack and Deflection of Basalt Fiber Reinforced Concrete Beams

2011 ◽  
Vol 243-249 ◽  
pp. 1058-1061
Author(s):  
Jun Wang ◽  
Huan Jun Ye ◽  
Zhi Wei Sun ◽  
Wei Chen
Keyword(s):  
Reinforced Concrete ◽  
Concrete Beam ◽  
Concrete Beams ◽  
Basalt Fiber ◽  
Volume Ratio ◽  
Reinforced Concrete Beam ◽  
Fiber Reinforced Concrete ◽  
Reinforced Concrete Beams ◽  
Engineering Practice ◽  
Fiber Reinforced

In order to research the influence of basalt fiber on the crack and deflection of the reinforced concrete beams, four basalt fiber reinforced concrete beams with the key parameters of length which were 12mm and 30mm and volume ratio which were 0.1% and 0.2% were designed and made. The test data was obtained through the bending experiment and the comparison with the common reinforced concrete beam. The result shows that it is obvious to control the crack and deflection of the test beams with the increasing of basalt fiber characteristic parameters. The calculation method of the maximum crack width of the basalt fiber reinforced concrete beams were presented based on the method of common concrete beam, which can provide the theoretical basis for the engineering practice.

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