Load capacity and stiffness of angular cross section reinforced concrete beams under torsion

2011 ◽  
Vol 11 (4) ◽  
pp. 885-903 ◽  
Author(s):  
M. KAMIŃSKI ◽  
W. PAWLAK
Keyword(s):  
Reinforced Concrete ◽  
Cross Section ◽  
Concrete Beams ◽  
Load Capacity ◽  
Reinforced Concrete Beams

scholarly journals Finite element analysis of reinforced concrete deep beam with large opening

2021 ◽  
Vol 10 (1) ◽  
Author(s):  
Elsayed Ismail ◽  
Mohamed S. Issa ◽  
Khaled Elbadry
Keyword(s):  
Finite Element ◽  
Reinforced Concrete ◽  
Concrete Beams ◽  
Load Capacity ◽  
Reinforced Concrete Beams ◽  
The Other ◽  
Deep Beam ◽  
Web Openings ◽  
Design Load ◽  
Large Opening

Abstract Background A series of nonlinear finite element (FE) analyses was performed to evaluate the different design approaches available in the literature for design of reinforced concrete deep beam with large opening. Three finite element models were developed and analyzed using the computer software ATENA. The three FE models of the deep beams were made for details based on three different design approaches: (Kong, F.K. and Sharp, G.R., Magazine of Concrete Res_30:89-95, 1978), (Mansur, M. A., Design of reinforced concrete beams with web openings, 2006), and Strut and Tie method (STM) as per ACI 318-14 (ACI318 Committee, Building Code Requirements for Structural Concrete (ACI318-14), 2014). Results from the FE analyses were compared with the three approaches to evaluate the effect of different reinforcement details on the structural behavior of transfer deep beam with large opening. Results The service load deflection is the same for the three models. The stiffnesses of the designs of (Mansur, M. A., Design of reinforced concrete beams with web openings, 2006) and STM reduce at a load higher than the ultimate design load while the (Kong, F.K. and Sharp, G.R., Magazine of Concrete Res_30:89-95, 1978) reduces stiffness at a load close to the ultimate design load. The deep beam designed according to (Mansur, M. A., Design of reinforced concrete beams with web openings, 2006) model starts cracking at load higher than the beam designed according to (Kong, F.K. and Sharp, G.R., Magazine of Concrete Res_30:89-95, 1978) method. The deep beam detailed according to (Kong, F.K. and Sharp, G.R., Magazine of Concrete Res_30:89-95, 1978) and (Mansur, M. A., Design of reinforced concrete beams with web openings, 2006) failed due to extensive shear cracks. The specimen detailed according to STM restores its capacity after initial failure. The three models satisfy the deflection limit. Conclusion It is found that the three design approaches give sufficient ultimate load capacity. The amount of reinforcement given by both (Mansur, M. A., Design of reinforced concrete beams with web openings, 2006) and (Kong, F.K. and Sharp, G.R., Magazine of Concrete Res_30:89-95, 1978) is the same. The reinforcement used by the STM method is higher than the other two methods. Additional reinforcement is needed to limit the crack widths. (Mansur, M. A., Design of reinforced concrete beams with web openings, (2006)) method gives lesser steel reinforcement requirement and higher failure load compared to the other two methods.

Performance of Reinforced Concrete Beams with Multiple Openings

2020 ◽  
Vol 857 ◽  
pp. 162-168
Author(s):  
Haidar Abdul Wahid Khalaf ◽  
Amer Farouk Izzet
Keyword(s):  
Reinforced Concrete ◽  
Ultimate Load ◽  
Concrete Beams ◽  
Load Capacity ◽  
Reinforced Concrete Beams ◽  
Design Parameters ◽  
Ultimate Load Capacity ◽  
Concentrated Load ◽  
Simply Supported ◽  
Group I

The present investigation focuses on the response of simply supported reinforced concrete rectangular-section beams with multiple openings of different sizes, numbers, and geometrical configurations. The advantages of the reinforcement concrete beams with multiple opening are mainly, practical benefit including decreasing the floor heights due to passage of the utilities through the beam rather than the passage beneath it, and constructional benefit that includes the reduction of the self-weight of structure resulting due to the reduction of the dead load that achieves economic design. To optimize beam self-weight with its ultimate resistance capacity, ten reinforced concrete beams having a length, width, and depth of 2700, 100, and 400 mm, respectively were fabricated and tested as simply supported beams under one incremental concentrated load at mid-span until failure. The design parameters were the configuration and size of openings. Three main groups categorized experimental beams comprise the same area of openings and steel reinforcement details but differ in configurations. Three different shapes of openings were considered, mainly, rectangular, parallelogram, and circular. The experimental results indicate that, the beams with circular openings more efficient than the other configurations in ultimate load capacity and beams stiffness whereas, the beams with parallelogram openings were better than the beams with rectangular openings. Commonly, it was observed that the reduction in ultimate load capacity, for beams of group I, II, and III compared to the reference solid beam ranged between (75 to 93%), (65 to 93%), and (70 to 79%) respectively.

scholarly journals Assessing the Instantaneous Stiffness of Cracked Reinforced Concrete Beams Based on a Gradual Change in Strain Distributions

2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
Chunyu Fu ◽  
Dawei Tong ◽  
Yuyang Wang
Keyword(s):  
Experimental Data ◽  
Reinforced Concrete ◽  
Cross Section ◽  
Concrete Beams ◽  
Internal Force ◽  
Experimental Results ◽  
Reinforced Concrete Beams ◽  
Gradual Change ◽  
Concrete Cracking ◽  
Good Agreement

Concrete cracking causes a gradual change in strain distributions along the cross section height of reinforced concrete beams, which will finally affect their instantaneous stiffness. A method for assessing the stiffness is proposed based on the gradual change, which is considered through modeling different strain distributions for key sections in cracked regions. Internal force equilibria are adopted to find a solution to top strains and neutral axes in the models, and then the inertias of the key sections are calculated to assess the beam stiffness. The proposed method has been validated using experimental results obtained from tests on five reinforced concrete beams. The predicted stiffness and displacements are shown to provide a good agreement with experimental data. The instantaneous stiffness is proven to greatly depend on the crack number and depth. This dependence can be exactly reflected by the proposed method through simulating the gradual change in concrete strain distributions.

Flexural capacity and design of hybrid FRP-steel-reinforced concrete beams

2019 ◽  
Vol 23 (7) ◽  
pp. 1290-1304
Author(s):  
Yang Yang ◽  
Ze-Yang Sun ◽  
Gang Wu ◽  
Da-Fu Cao ◽  
Zhi-Qin Zhang
Keyword(s):  
Reinforced Concrete ◽  
Cross Section ◽  
Concrete Beams ◽  
Reinforced Concrete Beams ◽  
Fiber Reinforced Polymer ◽  
Fiber Reinforced ◽  
Hybrid Fiber ◽  
Steel Reinforced Concrete ◽  
Reinforced Polymer ◽  
The Cross

This study presents a design method for hybrid fiber-reinforced-polymer-steel-reinforced concrete beams by an optimized analysis of the cross section. First, the relationships among the energy consumption, the bearing capacity, and the reinforcement ratio are analyzed; then, the parameters of the cross section are determined. Comparisons between the available theoretical and experimental results show that the designed hybrid fiber-reinforced-polymer-steel-reinforced concrete beams with a low area ratio between the fiber-reinforced polymer and the steel reinforcement could meet the required carrying capacity and exhibited high ductility.

Experimental Study on Reinforcement of Failure Reinforced Concrete Beams

2013 ◽  
Vol 275-277 ◽  
pp. 1264-1267
Author(s):  
Qian Chen ◽  
Ling Yong Liu ◽  
Yang Jun Meng
Keyword(s):  
Experimental Study ◽  
Reinforced Concrete ◽  
Bearing Capacity ◽  
Epoxy Resin ◽  
Cross Section ◽  
Concrete Beams ◽  
Experimental Results ◽  
Reinforced Concrete Beams ◽  
Carbon Cloth ◽  
Structural Failure

Through repair and reinforcement of breaking reinforced concrete beams by epoxy resin and carbon cloth, and its experiment, the crack and deformation and bearing capacity as well as ductility of such beams are obtained. Experimental results show that the ultimate bearing capacity of beams after reinforcement increased by 210%, the structure ductility fell by 170%, structural failure form is similar to failure in normal cross section.

scholarly journals A Parametrical Analysis for the Rotational Ductility of Reinforced Concrete Beams

2013 ◽  
Vol 7 (1) ◽  
pp. 242-253
Author(s):  
Domenico Raffaele ◽  
Giuseppina Uva ◽  
Francesco Porco ◽  
Andrea Fiore
Keyword(s):  
Reinforced Concrete ◽  
Cross Section ◽  
Concrete Beams ◽  
Closed Form Solution ◽  
Form Solution ◽  
Reinforced Concrete Beams ◽  
Shear Cracks ◽  
Technical Standards ◽  
Mechanical Reinforcement ◽  
Plastic Rotation

The assessment of the plastic rotation of reinforced concrete beams is an essential aspect to avoid structural brittle collapses. The value actually available can be generally determined as sum of two different components. The first, due to bending, the second for inclined shear cracks. This paper presents a simplified model which provides the flexural plastic rotation of the rectangular beams with a ``closed-form solution''. The approach is substantially dimensionless and includes main influencing factors the cross -section, as mechanical material properties, ductility, geometrical and mechanical reinforcement ratio, confinement effects. In closing, in order to appreciate the reliability of the procedure, a comparison with models proposed by international technical standards is made.

scholarly journals Strengthening of Reinforced Concrete Members using Post-Tension Cables: A Parametric Research

2019 ◽  
Vol 8 (2S3) ◽  
pp. 1334-1338
Keyword(s):  
Reinforced Concrete ◽  
Parametric Study ◽  
Concrete Beams ◽  
Load Capacity ◽  
Reinforced Concrete Beams ◽  
Design Parameters ◽  
Internal Stresses ◽  
Force Magnitude ◽  
Post Tensioning ◽  
Post Tension

In building construction, post-tensioning allows longer clear spans, thinner slabs than the reinforced concrete beams. This paper presents a theoretical investigation on the behavior of existing reinforced concrete beams strengthened with post-tensioning cable(s) for increasing their load capacity. The proposed post-tensioning technique consists of stressing cable passing through a structural beam element starting from the top/bottom side and traversing the beam to the bottom/top side and then return back to the original side. A theoretical parametric study is conducted to study the effect of post-tensioning parameters on the internal stresses to optimize the design parameters. An excel spread sheet program was developed to calculate the internal straining actions at critical sections of the beam. A parametric study including the cable length, inclination angle of the cable and pre-stressing force magnitude was performed by using this program. This parametric study, led to well-defined guidelines for the proper use of the strengthening of beams by pre-stressing cables with adequate geometrical conditions of the cables

scholarly journals Post-strengthening of reinforced concrete beams with prestressed CFRP strips. Part 1: analysis under static loading

2012 ◽  
Vol 5 (3) ◽  
pp. 343-361
Author(s):  
M. R. Garcez ◽  
G. L. C. P. Silva Filho ◽  
Urs Meier
Keyword(s):  
Reinforced Concrete ◽  
Concrete Beams ◽  
Load Capacity ◽  
Experimental Studies ◽  
Reinforced Concrete Beams ◽  
Experimental Program ◽  
Existing Structures ◽  
Flexural Tests ◽  
Strengthening Technique ◽  
Epoxy Matrices

Different FPR post-strengthening techniques have been developed and applied in existing structures aiming to increase their load capacity. Most of the FRP systems used nowadays consist of carbon fibers embedded in epoxy matrices (CFRP). Regardless of the advantages and the good results shown by the CFRP post-strengthen technique, experimental studies show that, in most cases, the failure of post-strengthened structures is premature. Aiming to better use the tensile strength of the carbon fiber strips used as post-strengthening material, the application of prestressed CFRP strips started to be investigated. The main purpose of this paper is to analyze the effects of the composite prestressing in the performance of the CFRP post strengthening technique. The experimental program was based on flexural tests on post-strengthened reinforced concrete beams subjected to static - part 1 and cyclic - part 2 loading. Experimental results allowed the analysis of the quality and shortcomings of post-strengthen system studied, which resulted in valuable considerations about the analyzed post-strengthened beams.

Sign in / Sign up

Export Citation Format

Share Document