scholarly journals Contact and Noncontact Ultrasonic Nondestructive Test in Reinforced Concrete Beam

2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
Jason Maximino C. Ongpeng ◽  
Andres Winston C. Oreta ◽  
Sohichi Hirose
Keyword(s):  
Reinforced Concrete ◽  
Concrete Beam ◽  
Plain Concrete ◽  
Reinforced Concrete Beam ◽  
Ultrasonic Test ◽  
Reinforced Concrete Beams ◽  
Cement Ratio ◽  
Water Cement Ratio ◽  
Air Gaps ◽  
Wave Path

Contact-type ultrasonic test is commonly used in construction industry where gel-couplant is applied to the material being tested and the transducers to assure that wave propagation will travel through without any air gaps. However, this method has disadvantages, since surface preparation is considered prior to testing. Another method of testing without the worry of air gaps that causes scattering of waves before it reaches the medium is the use of the noncontact ultrasonic test. In particular, the air-coupled ultrasonic test is done in this paper for reinforced concrete beams. Sixteen plain concrete cube specimens under the compression test and six reinforced concrete beam specimens under the four-point bending test are made with water-cement ratio of 40% and 60%. The plain concrete cubes are investigated to establish the relationship of the contact ultrasonic test and load. Added parameters are considered to investigate the sensitivity of the contact and noncontact ultrasonic test in reinforced concrete beams. These are ultrasonic wave path and the neutral axis index. It shows that the higher water-cement ratio produces good sensitivity in the noncontact ultrasonic test, since it produces more cracks on the tension face. Lower water-cement ratio gives good sensitivity with load for the contact ultrasonic test, since it has its ultrasonic wave path passing through the concrete experiencing compression. In addition, the neutral axis index for a member subjected to bending is an important factor in assessing the sensitivity of both contact and noncontact ultrasonic test.

Air-coupled Nonlinear Ultrasonic Test for Reinforced Concrete Beams

2018 ◽  
Author(s):  
Jason Maximino C. Ongpeng ◽  
Kenneth Guevarra ◽  
Sohichi Hirose
Keyword(s):  
Reinforced Concrete ◽  
Concrete Beams ◽  
Second Harmonic ◽  
Ultrasonic Test ◽  
Test Method ◽  
Reinforced Concrete Beams ◽  
Bending Test ◽  
Harmonic Amplitude ◽  
Cement Ratio ◽  
Water Cement Ratio

<p>Air-coupled ultrasonic test is a non-destructive test method for investigating damage in material. In this paper, reinforced concrete beams with one 8-mm diameter rounded bar were casted and tested under four-point bending test with water-cement ratio of 40% and 60%. The transducers were placed and focused on the horizontal surface with induced 3mm notch at the midpoint where maximum tension occurred and crack formation was located. Frequency domain waveform was used specifically to analyze second harmonic generation (SHG). There were two metrics used under the SHG, these were: second harmonic amplitude (SHA) and second harmonic ratio (SHR). The SHR proved to be consistent for both water-cement ratio and it behaved increasing as damage in tension increases.</p>

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.

In-Plane Force Effect of Reinforced Concrete Beam with Elastic Supports

2011 ◽  
Vol 287-290 ◽  
pp. 1896-1901
Author(s):  
Zhi Kun Guo ◽  
Wan Xiang Chen ◽  
Qi Fan Wang ◽  
Yu Huang ◽  
Chao Pu Li ◽  
...  
Keyword(s):  
Reinforced Concrete ◽  
Concrete Beam ◽  
Reinforced Concrete Beam ◽  
Reinforced Concrete Beams ◽  
Nonlinear Characteristics ◽  
Elastic Supports ◽  
Calculation Results ◽  
Basic Equations ◽  
First Time ◽  
Good Agreement

The bearing capacities of one-way reinforced concrete beams with elastic supports are investigated in this paper. According to the nonlinear characteristics of the beams, the basic equations based on plastic theory of concrete are derived by considering the in-plane force effects that aroused by the constraints of supports when the beams deforming. It is indicated that the calculation results are in good agreement with experimental datum, and the influences of different supports on the bearing capacities of the beams are quantitatively given for the first time.

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 Nonlinear creep in a steel-reinforced concrete beam

2020 ◽  
Vol 17 (5) ◽  
pp. 108-116
Author(s):  
S. O. Chepilko ◽  
Keyword(s):  
Reinforced Concrete ◽  
Concrete Beam ◽  
Reinforced Concrete Beam ◽  
Reinforced Concrete Beams ◽  
Nonlinear Creep ◽  
Short Term ◽  
Nonlinear Integral Equations ◽  
Steel Reinforced Concrete ◽  
Linear Creep ◽  
Resolving System

Problems of taking into account nonlinear creep in steel- reinforced concrete beams are considered basing on the integral equation of viscous-elastic-plasticity of concrete. There has been obtained the resolving system of nonlinear integral equations, a linearization of this system has been carried out, its asymptotic solutions have been written out for the theory of elastic heredity case. The analysis of taking into account nonlinear creep has been performed compared with the linear creep equations and an instantaneous (short-term) loading allowing for concrete’s nonlinear diagram.

scholarly journals The flexural behavior model of bamboo reinforced concrete beams using a hose clamp

2019 ◽  
Vol 276 ◽  
pp. 01033
Author(s):  
Muhtar ◽  
Sri Murni Dewi ◽  
Wisnumurti ◽  
As’ad Munawir
Keyword(s):  
Reinforced Concrete ◽  
Concrete Beam ◽  
Load Capacity ◽  
Reinforced Concrete Beam ◽  
Load Test ◽  
Reinforced Concrete Beams ◽  
Flexural Behavior ◽  
Steel Reinforced Concrete ◽  
And Behavior ◽  
Hose Clamp

Bamboo can use at the simple concrete construction because of the tensile strength of its mechanical property. Meanwhile, a slippery surface of the bamboo caused cracks in the bamboo reinforced concrete beam (BRC) not to spread and yield slip failure between a bamboo bar and concrete. Load test at the BRC beam yield humble load capacity. This study aims to improve the capacity and behavior of BRC beam bending by giving waterproof coating, sand, and hose clamp installation. The beam test specimen with the size of 75x150x1100mm made as many as 26 pieces with the variety of reinforcement. The hose clamp used on the bamboo reinforcement varies with a distance of 0 cm, 15 cm, 20 cm, and 25 cm. The testing using a simple beam with two-point loading. The test results show that BRC beams have different bending behavior compared to the steel reinforced concrete beam (SRC).

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.

Research on Reinforced Concrete Beam Enlarged Cross Section Method Experiment and Finite Element Simulation

2014 ◽  
Vol 638-640 ◽  
pp. 208-213 ◽  
Author(s):  
Yuan Yuan Li ◽  
Bin Guo ◽  
Jiang Liu
Keyword(s):  
Finite Element ◽  
Reinforced Concrete ◽  
Finite Element Simulation ◽  
Cross Section ◽  
Concrete Beam ◽  
Performance Test ◽  
Bending Strength ◽  
Reinforced Concrete Beam ◽  
Reinforced Concrete Beams ◽  
Element Simulation

Increasing the beam cross section is a kind of traditional and universal strengthening methods of civil structure. The mechanical performance test were studied on the mechanics performance and deformation of four reinforced concrete beams in this study. The results show that increase of the cross section and tensile area at the bottom of the steel could effectively improve the performance of mechanical. The beam crack load, yield load, ultimate load and bending strength are increasing with cross section and mechanical. By simulating the relationship bwteen load and deflection. It is concluded that The finite element simulation of reinforced concrete beam with the reasonable concrete unit and reinforced unit can meet the demand of practical engineering.

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