Estimation of Ultimate Tendon Stress in Reinforced Concrete Beams Prestressed with External FRP Tendons

Test Results ◽

Stress Increment ◽

Hinge Zone ◽

Good Agreement

The ultimate tendon stress is the key to calculation of flexural capacity in reinforced concrete beam prestressed with external FRP tendons (RCBPEFT). Based on the theory of equivalent plastic hinge zone, the general formulas for calculating the ultimate tendon stress increment and ultimate tendon stress in RCBPEFT are therefore proposed. Comparisons indicate that the predictions are in good agreement with the test results.

Experiment on the Deformation of the Reinforced Concrete Beam NSM Prestressed Steel Spiral Ribs

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.94-96.1278 ◽

2011 ◽

Vol 94-96 ◽

pp. 1278-1285

Author(s):

Chun Sheng Zhang ◽

Mei Xiang Zhang ◽

Ya Hong Ding

Keyword(s):

Reinforced Concrete ◽

Concrete Beam ◽

Concrete Beams ◽

Steel Wire ◽

Concrete Cover ◽

Practical Engineering ◽

General Deformation ◽

Good Agreement

A new reinforcement technology with prestressed helical rib steel wire bonded in sawed grooves in the concrete cover is presented, based on the deficiency of the presented reinforcement methods. Four test beams NSM prestressed steel spiral ribs are tested in this paper. The stiffness expression of the reinforced concrete beams in different stages is derived and the stiffness formulas of the reinforced concrete beams are gained, based on the general deformation principles of reinforced concrete beams and the characteristics of the reinforced concrete beam NSM prestressed steel spiral ribs. The results of the calculation and the experimental results show good agreement. It shows that the reinforced concrete beam NSM prestressed steel spiral ribs can effectively delay the development of cracks, reduce the component deformation and increase its stiffness. The results provide an experimental basis for the reinforcement method in practical engineering applications.

Experimental Study on Shear of Reinforced Concrete Beams with High Strength Rebars as Stirrups under Different Shear Span Ratios

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.578-579.164 ◽

2014 ◽

Vol 578-579 ◽

pp. 164-167 ◽

Cited By ~ 2

Author(s):

Peng Li ◽

Xian Tang Zhang ◽

Ming Ping Wang

Keyword(s):

Reinforced Concrete ◽

Concrete Beam ◽

Concrete Beams ◽

High Strength ◽

Shear Behavior ◽

Shear Capacity ◽

Test Results ◽

Shear Span

To investigate the influence of shear span ratio for the shear behavior of reinforced concrete beam with HRBF500 high strength rebars as stirrups, an experiment was carried out, which included 8 simply supported beams with HRBF500 rebars as stirrups. Under concentrated loads, the crack, deflection, strain of rebars, bearing capacity and failure mode are observed under different shear span ratios. Some comparisons are made between test results and calculated outcome. It shows that the shear span ratio has very important influent on the shear behavior of reinforced concrete beam with HRBF500 high strength bars as stirrups. Formula in code for design of concrete structures can be used to calculate its shear capacity with enough safety.

Experimental and Theoretical Studies on Flexural Performance of Stainless Steel Reinforced Concrete Beams

Advances in Civil Engineering ◽

10.1155/2020/4048750 ◽

2020 ◽

Vol 2020 ◽

pp. 1-13 ◽

Cited By ~ 1

Author(s):

Qingfu Li ◽

Wei Guo ◽

Chenhui Liu ◽

Yihang Kuang ◽

Huitao Geng

Keyword(s):

Stainless Steel ◽

Reinforced Concrete ◽

Bearing Capacity ◽

Failure Mode ◽

Concrete Beam ◽

Concrete Beams ◽

Test Results ◽

Calculation Results

In this paper, the flexural characteristics of stainless steel (SS) reinforced concrete beams are studied and analyzed. We mainly focus on their crack mode, failure mode, load-deflection curve, and bearing capacity. Six beams with test parameters, including the diameter of reinforcement, the type of the reinforcement, and the stirrup spacing, were tested in 4-point bending. The test results indicate that the failure mode of SS reinforced concrete beam can be divided into three stages: elastic stage, cracking stage, and failure stage. The midspan section deformation of SS reinforced concrete beam conforms to the assumption of plane section. Under the same reinforcement condition, the normal section and the oblique section bearing capacities of the SS reinforced concrete beams are significantly higher than those of the ordinary reinforced concrete beams. In addition, the prediction of cracking moment and bearing capacity calculated by ACI 318-14 and GB 50010-2010 was also evaluated. The calculation results of the two codes were safe and conservative, and GB 50010-2010 provided more accurate prediction of cracking moments. Furthermore, to verify the reliability of the test results, finite element models were established and the analytical results corroborated well with the test results.

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

Advances in Structural Engineering ◽

10.1177/1369433218761140 ◽

2018 ◽

Vol 21 (13) ◽

pp. 1977-1989 ◽

Cited By ~ 4

Author(s):

Tengfei Xu ◽

Jiantao Huang ◽

Arnaud Castel ◽

Renda Zhao ◽

Cheng Yang

Keyword(s):

Reinforced Concrete ◽

Concrete Beam ◽

Natural Frequencies ◽

Concrete Beams ◽

Dynamic Stiffness ◽

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

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.214.306 ◽

2012 ◽

Vol 214 ◽

pp. 306-310

Author(s):

Han Chen Huang

Keyword(s):

Genetic Algorithm ◽

Reinforced Concrete ◽

Concrete Beam ◽

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

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.287-290.1896 ◽

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 ◽

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

Advances in Structural Engineering ◽

10.1177/1369433220904006 ◽

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 ◽

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

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.707.51 ◽

2016 ◽

Vol 707 ◽

pp. 51-59 ◽

Cited By ~ 1

Author(s):

Osama Ahmed Mohamed ◽

Rania Khattab

Keyword(s):

Reinforced Concrete ◽

Concrete Beam ◽

Ultimate Load ◽

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.

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

Materials ◽

10.3390/ma13010234 ◽

2020 ◽

Vol 13 (1) ◽

pp. 234 ◽

Cited By ~ 2

Author(s):

Yingwu Zhou ◽

Yaowei Zheng ◽

Lili Sui ◽

Biao Hu ◽

Xiaoxu Huang

Keyword(s):

Reinforced Concrete ◽

Concrete Beam ◽

Concrete Beams ◽

Steel Corrosion ◽

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

Proceedings of International Structural Engineering and Construction ◽

10.14455/isec.res.2017.100 ◽

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 ◽

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.