Influence of the percentage of reinforcement damage on the bearing-capacity of RC beams

PurposeReinforcement of reinforced concrete (RC) beams in-service have always been an important research field, anchoring steel plate in the bottom of the beams is a kind of common reinforcement methods. In actual engineering, the contribution of pavement layer to the bearing capacity of RC beams is often ignored, which underestimates the bearing capacity and stiffness of RC beams to a certain extent. The purpose of this paper is to study the effect of pavement layer on the RC beams before and after reinforcement.Design/methodology/approachFirst, static load experiments are carried out on three in-service RC hollow slab beams, meanwhile, nonlinear finite element models are built to study the bearing capacity of them. The nonlinear material and shear slip effect of studs are considered in the models. Second, the finite element models are verified, and the numerical simulation results are in good agreement with the experimental results. Last, the finite element models are adopted to carry out the research on the influence of different steel plate thicknesses on the flexural bearing capacity and ductility.FindingsThe experimental results showed that pavement layers increase the flexural capacity of hollow slab beams by 16.7%, and contribute to increasing stiffness. Ductility ratio of SPRCB3 and PRCB2 was 30% and 24% lower than that of RCB1, respectively. The results showed that when the steel plate thickness was 1 mm–6 mm, the bearing capacity of the hollow slab beam increased gradually from 2158.0 kN.m to 2656.6 kN.m. As the steel plate thickness continuously increased to 8 mm, the ultimate bearing capacity increased to 2681.0 kN.m. The increased thickness did not cause difference to the bearing capacity, because of concrete crushing at the upper edge.Originality/valueIn this paper, based on the experimental study, the bearing capacity of hollow beam strengthened by steel plate with different thickness is extrapolated by finite element simulation, and its influence on ductility is discussed. This method not only guarantees the accuracy of the bearing capacity evaluation, but also does not require a large number of samples, and has certain economy. The research results provide a basis for the reinforcement design of similar bridges.

Download Full-text

Fracture toughness of RC beams on the shear, strengthening by FRCM system

MATEC Web of Conferences ◽

10.1051/matecconf/201818302009 ◽

2018 ◽

Vol 183 ◽

pp. 02009 ◽

Cited By ~ 9

Author(s):

Zinoviy Blikharskyy ◽

Pavlo Vegera ◽

Rostyslav Vashkevych ◽

Taras Shnal

Keyword(s):

Fracture Toughness ◽

Bearing Capacity ◽

Shear Failure ◽

Control Sample ◽

Variable Parameter ◽

Rc Beams ◽

Maximum Width ◽

Shear Span ◽

Initial Load ◽

Inclined Cracks

This research paper present the experimental study of reinforce concrete beams strengthened by FRCM system in the shear area. All samples are without transverse reinforcement at the shear distance. First beams tested as control sample, with shear distance a/d=2. Another three beams tested with strengthening by FRCM system. Variable parameter is the level of initial load, before strengthening. The initial load values were 0, 0.3, 0.5 from carrying capacity of control samples. All RC beams were designed to fail in shear, even strengthened samples. In the result of this research we determined that fracture toughness of RC beams increases with a decrease of span to the effective depth ratio. Results are comparable with the increasing of bearing capacity. The first inclined crack opend in mid-height cross section at the load 50 kN at an angle equal to 450 and it does not depend on the shear span. The maximum width of inclined cracks decrease with decreasing of shear span. The maximum width of inclined cracks decrease with decreasing of the shear span. The maximum values of width of inclined cracks are fixed at the value of 0.55 - 0.85 mm. Using the limit crack opening width as criteria of exhaustion of serviceability (SLS) we saw that about 16 - 29% of bearing capacity still remains before the danger of shear failure of the beam.

Download Full-text

Experimental and Numerical Study on Ultimate Shear Load Carrying Capacity of Corroded RC Beams

Advances in Civil Engineering ◽

10.1155/2021/4848483 ◽

2021 ◽

Vol 2021 ◽

pp. 1-12

Author(s):

Zhanzhan Tang ◽

Zhixiang He ◽

Zheng Chen ◽

Lingkun Chen ◽

Hanyang Xue ◽

...

Keyword(s):

Shear Strength ◽

Bearing Capacity ◽

Cross Section ◽

Loss Rate ◽

Numerical Study ◽

Rc Beams ◽

Load Carrying ◽

Shear Bearing Capacity ◽

The Cross ◽

The Impact

For an RC beam, the strength of steel rebar, the bonding strength between the concrete and reinforcement, and the bite action between the aggregates will deteriorate significantly due to corrosion. In the present study, 10 RC beams were designed to study the impact of corrosion on the shear bearing capacity. The mechanism of corrosion for stirrups and longitudinal bars and their effects were analyzed. Based on the existing experimental data, the correlation between the stirrup corrosion factor and the cross section loss rate was obtained. An effective prediction formula on the shear bearing capacity of the corroded RC beams was proposed and validated by the experimental results. Moreover, a numerical analysis approach based on the FE technique was proposed for the prediction of the shear strength. The results show that corrosion of the reinforcements could reduce the shear strength of the RC beams. The corrosion of stirrups can be numerically simulated by the reduction of the cross section. The formulae in the literature are conservative and the predictions are very dispersed, while the predictions by the proposed formula agree very well with the experiment results.

Download Full-text

Assesment of Main Models for Predicting Debonding Load-Bearing Capacity against Intermediate Crack-Induced Debonding Failure in FRP-Strengthened RC Beams

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.311-313.1941 ◽

2011 ◽

Vol 311-313 ◽

pp. 1941-1944

Author(s):

Gui Bing Li ◽

Yu Gang Guo ◽

Xiao Yan Sun

Keyword(s):

Bearing Capacity ◽

Failure Mode ◽

Failure Modes ◽

Rc Beams ◽

Test Results ◽

Load Bearing Capacity ◽

Load Bearing ◽

Accuracy Test ◽

New Models ◽

Debonding Load

intermediate crack-induced debondingis one of the most dominant failure modes in FRP-strengthened RC beams. Different code models and provisions have been proposed to mitigateintermediate crack-induced debondingfailure.However, these models and provisions can not mitigate this failure mode effectively. Recnetly, new models have been proposed to solve this problem. Out of all the existing models, four typical ones are investigated in the current study. A comprehensivecomparison among these models is carried out in order to evaluate their performance and accuracy. Test results ofﬂexural specimens with intermediate crack-induced debonding failurecollected from the existing literature are used in the current comparison. The effectivenessand accuracy of each model have been evaluated based on these experimental results. It is shown that the current modals are all conservative and inadequite to effectively mitigate intermediate crack-induced debonding in flexurally strengthened members.

Download Full-text

Bearing capacity of RC beams reinforced with high strength rebars and steel plate

MATEC Web of Conferences ◽

10.1051/matecconf/201823002003 ◽

2018 ◽

Vol 230 ◽

pp. 02003 ◽

Cited By ~ 13

Author(s):

Taras Bobalo ◽

Yaroslav Blikharskyy ◽

Rostyslav Vashkevich ◽

Myhailo Volynets

Keyword(s):

Reinforced Concrete ◽

Bearing Capacity ◽

Steel Plate ◽

Concrete Structures ◽

High Strength ◽

Strength Properties ◽

Rc Beams ◽

Reinforcing Bars ◽

External Reinforcement ◽

Effective Use

Nowadays, reducing the material content of not only buildings and structures in general, but also individual constructions is a topical task that can be realized through the use of high-strength concrete and reinforcement, as well as with the use of external reinforcement. The concentrated location of sheet reinforcement on the external the most tense facets of steel and concrete structures increases the operating height of the cross-section, makes it possible to more effectively use the strength properties of steel in comparison with conventional reinforced concrete, and with the same bearing capacity to economize on expenses. Composite and monolithic reinforced concrete structures with external reinforcement are used in various construction sectors around the world. This contributed to the expansion of the use of reinforced concrete for special buildings of power-engineering and hydrotechnical construction. The technical nd econom efficiency, as well as the possibility of using external rebar as formwork for monolithic concrete construction, have been proved. Therefore, there is a need for the study of structures with combined reinforcement, in which high rigidity of steel and concrete structures is combined with an effective use of high-strength reinforcing bars (rebar) without prior tension

Download Full-text

Bearing Capacity of Beams Strengthened by Common Methods Considering Strain Lag Effect

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.166-169.1789 ◽

2012 ◽

Vol 166-169 ◽

pp. 1789-1792 ◽

Cited By ~ 1

Author(s):

Si Meng Liu ◽

Qing Yang Liu

Keyword(s):

Bearing Capacity ◽

Rc Beams ◽

Critical States ◽

Loading Process ◽

Lag Effect ◽

The World ◽

Non Linear ◽

Reinforcing Material

A lot of bridge reinforcement and rehabilitation projects are been implementing throughout China and many countries in the world. However, some fundamental questions still remain unsettled, and this paper addressed one of them, which is the bearing capacity of strengthened beams. We analyzed the loading process of beams after strengthening with strain lag effect, and focused on several critical states. To validate our conclusions, we developed a non-linear FEM program, and compared the data yielded by program with those from reference. We found that for adequate reinforcement RC beams the influence of strain lag effect on the bearing capacity depends on the property of reinforcing material. The conclusion matched with experiment very well.

Download Full-text

Test Analysis for RC Beams Strengthened with Externally Bonded Prestressed CFRP Laminates

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.385-387.41 ◽

2008 ◽

Vol 385-387 ◽

pp. 41-44 ◽

Cited By ~ 1

Author(s):

Shi Qi Cui ◽

Jin Shan Wang ◽

Zhao Zhen Pei ◽

Zhi Liu

Keyword(s):

Reinforced Concrete ◽

Bearing Capacity ◽

Concrete Beams ◽

Reinforced Concrete Beams ◽

Rc Beams ◽

Test Results ◽

Test Analysis ◽

Cfrp Laminates ◽

Cfrp Sheet ◽

Externally Bonded

Reinforced concrete beams strengthened with externally bonded CFRP sheet and prestressed CFRP are analyzed in this paper. Crack developments and displacements with curvatures for different beams are analyzed. Test results show that prestressed CFRP are able to control the development of macro cracks in concrete and prestressed CFRP is an effective method to improve the toughness of concrete, reduce strengthening cost and meanwhile enhance bearing capacity of concrete beams.

Download Full-text

Mechanical Properties of Strengthened RC Beams using Steel Plates

International Journal of Innovative Technology and Exploring Engineering - Special Issue ◽

10.35940/ijitee.d1444.049620 ◽

2020 ◽

Vol 9 (4) ◽

pp. 1208-1217

Keyword(s):

Mechanical Properties ◽

Bearing Capacity ◽

Steel Plate ◽

Fem Analysis ◽

Steel Plates ◽

Rc Beam ◽

Rc Beams ◽

Load Bearing Capacity ◽

Load Bearing ◽

Single Row

The focus of this analysis is the review of steel plate strengthened RC beams using Single row and Stagger row bolt arrangements and to compare the bonding behaviour of different bolts arrangement under flexure. Also, to investigate the behaviour, load bearing capacity and the deflection for control and steel plate bonded beams. This research is constrained by FEM analysis utilizing ANSYS to the actions of standard RC Beam and RC beam steel plate associated.

Download Full-text