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 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 A load capacity of cyclic loaded reinforced concrete beams

2014 ◽  
Vol 13 (3) ◽  
pp. 079-086
Author(s):  
Barbara Goszczyńska ◽  
Wiesław Trąmpczyński ◽  
Magdalena Bacharz ◽  
Kamil Bacharz
Keyword(s):  
Reinforced Concrete ◽  
Comparative Analysis ◽  
Cyclic Load ◽  
Concrete Beams ◽  
Load Capacity ◽  
Reinforced Concrete Beams ◽  
Longitudinal Reinforcement ◽  
Simply Supported ◽  
Monotonic Load

In this paper, an effect of cyclic and variable loads on the capacity of reinforced concrete beams is investigated. The study was conducted on 28 reinforced concrete beams including 12 two-span beams - statically indeterminate and 16 simply supported single-span beams. Those beams were differentiated by the structure and degree of longitudinal reinforcement (two degrees of reinforcement) and load applied programs (three programs types) including the monotonic load, load with unloadings and cyclic load. The last one was taken as a sinusoidal cyclic load with 100,000 cycles carried out for three ranges of loading forces. On the basis of a comparative analysis it can be concluded that in the case of the two-span beams, the imposition of 252,000 load cycles results in 20% drop of the beam capacity. Such an effect is not observed for load with unloadings and in the case of simply supported beams.

Shear Strengthening of Reinforced Concrete Beams with HFRP Composite

2016 ◽  
Vol 860 ◽  
pp. 152-155
Author(s):  
Sanyawit Siriluk ◽  
Qudeer Hussain ◽  
Winyu Rattanapitikon ◽  
Amorn Pimanmas
Keyword(s):  
Reinforced Concrete ◽  
Ultimate Load ◽  
Natural Fiber ◽  
Load Capacity ◽  
Reinforced Concrete Beams ◽  
Deep Beam ◽  
Fiber Layer ◽  
Ultimate Load Capacity ◽  
Shear Strengthening ◽  
Hemp Fiber

This paper presents an experimental study on the strengthening of scaled reinforced concrete (RC) deep beam using hemp fiber reinforced polymer (HFRP) composite. HFRP is the composite material which compose of hemp fiber bonding with epoxy resin. The major benefit of using hemp fiber is that their low price, high toughness, and hemp is natural fiber product which that can be found locally. In this study 2 different fiber orientation has been apply to scaled deep beam and also different in thickness (fiber layer). Three scaled deep beam were strengthened using HFRP composite, remaining one beam was tested as control (unstrengthen) beam. The test result show that HFRP composite are effective to enhance ultimate load capacity for RC beam. The HFRP composite applied in U-Shape was result into higher ultimate load compare with the sample that applied with both side strengthen method

scholarly journals Investigating Some Parameters Affecting Flexural Behaviour of Reinforced Concrete Beams Strengthened with CFRP Laminate

2018 ◽  
Vol 2 (5) ◽  
Author(s):  
Azad A. Mohammed
Keyword(s):  
Reinforced Concrete ◽  
Concrete Beams ◽  
Load Capacity ◽  
Reinforced Concrete Beams ◽  
Flexural Behaviour ◽  
Ultimate Load Capacity ◽  
Cfrp Laminate ◽  
Steel Rebar ◽  
Effective Depth ◽  
Strengthened Beam

In this paper, the influence of some important parameters affecting flexural behaviour of reinforced concrete beams strengthened with one layer of CFRP laminate has been studied. For this purpose, six reinforced concrete beams were cast and tested in the laboratory. Based on the obtained data, when CFRP laminate is applied to the tension face, too close to the steel rebar, the flexural strength of the strengthened beam is reduced. In general, the performance of the beam strengthened with one wide CFRP strip is better than that strengthened with two equivalent narrow strips. Ultimate load capacity of each strengthened beam was calculated based on the method given by the ACI 440.2R and compared with the test one. It is concluded that to avoid the steel rebar-CFRP laminate interaction effect, the CFRP laminate depth to the effective depth ratio (df / d) should not be smaller than about 1.17.

FLEXURAL BEHAVIOR OF STRENGTHENED AND RPIARED SUSTAINABLE R.C. BEAMS USING REACTIVE POWDER CONCRETE JACKET

2021 ◽  
Vol 25 (Special) ◽  
pp. 4-44-4-56
Author(s):  
Mohammed S. Zimmawe ◽  
◽  
Nagham T. Hamad ◽  
Keyword(s):  
Reinforced Concrete ◽  
Ultimate Load ◽  
Coarse Aggregate ◽  
Concrete Beams ◽  
Load Capacity ◽  
Reinforced Concrete Beams ◽  
Flexural Behavior ◽  
Reactive Powder Concrete ◽  
Limit Condition ◽  
Reactive Powder

Thin fiber reinforcement and rehabilitation of reinforced concrete beams Concrete jackets have several benefits, including increased ultimate load and improved serviceability limit condition. The current paper was carried out to investigate the effect of the strengthening and repairing by using reactive powder concrete(RPC) jacket for reinforced concrete beams that’s casted with recycled coarse aggregate (RCA) in enhancement the mechanical properties such as load capacity and deflection . Nine reinforced concrete beams mm were casted by using RCA with constant details and jacketed with RPC with variable of steel fiber content and jacket thickness to estimate the optimum details. The result showed the effectiveness of the proposed technique in both deflection and ultimate load.

scholarly journals THE ULTIMATE SHEAR STRENGTH OF SCC BEAMS STRENGTHENED BY INCLINED CFRP STRIPS

2019 ◽  
Vol 7 (1) ◽  
pp. 1-9
Author(s):  
Sarmad Sh. Abdulqader
Keyword(s):  
Shear Strength ◽  
Reinforced Concrete ◽  
Concrete Beams ◽  
Load Capacity ◽  
Reinforced Concrete Beams ◽  
Shape Effect ◽  
Ultimate Shear Strength ◽  
Simply Supported ◽  
Cfrp Sheets ◽  
Two Sides

This paper presents an experimental study of structural behavior of self-compacting reinforced concrete beams strengthened in shear by inclined CFRP strips. The experimental work consists of casting and testing of nine simply supported reinforced concrete beams. In this study, three parameters were considered, the configuration of CFRP sheets wrapping system, i.e two sides and U-shape, effect of horizontal strap of CFRP strips and CFRP strengthening area. The results showed that the presence of the horizontal strap of CFRP strips on the inclined strips increases the shear strength and the ultimate carrying load capacity by 8 to 15% and 7 to 10%, respectively in compare with the wrapping system of the CFRP strips.

Flexural Performance of Reinforced Concrete Built-up Beams with SIFCON

2020 ◽  
Vol 38 (5A) ◽  
pp. 669-680
Author(s):  
Ghazwan K. Mohammed ◽  
Kaiss F. Sarsam ◽  
Ikbal N. Gorgis
Keyword(s):  
Reinforced Concrete ◽  
Ultimate Load ◽  
Concrete Beams ◽  
Steel Fibers ◽  
Reinforced Concrete Beams ◽  
Load Carrying Capacity ◽  
Conventional Concrete ◽  
Flexural Performance ◽  
Load Carrying ◽  
Fiber Concrete

The study deals with the effect of using Slurry infiltrated fiber concrete (SIFCON) with the reinforced concrete beams to explore its enhancement to the flexural capacity. The experimental work consists of the casting of six beams, two beams were fully cast by conventional concrete (CC) and SIFCON, as references. While the remaining was made by contributing a layer of SIFCON diverse in-depth and position, towards complete the overall depths of the built-up beam with conventional concrete CC. Also, an investigation was done through the control specimens testing about the mechanical properties of SIFCON. The results showed a stiffer behavior with a significant increase in load-carrying capacity when SIFCON used in tension zones. Otherwise high ductility and energy dissipation appeared when SIFCON placed in compression zones with a slight increment in ultimate load. The high volumetric ratio of steel fibers enabled SIFCON to magnificent tensile properties.

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.

scholarly journals RETROFITTING AND DACTILITY OF REINFORCED CONCRETE BEAMS USING AN EXTERNAL REINFORCEMENT METHOD

2019 ◽  
Vol 3 (2) ◽  
pp. 135
Author(s):  
Novita Ike Triyuliani ◽  
Sri Murni Dewi ◽  
Lilya Susanti
Keyword(s):  
Reinforced Concrete ◽  
Ultimate Load ◽  
Concrete Beams ◽  
Concrete Block ◽  
Steel Reinforcement ◽  
Reinforced Concrete Beams ◽  
Building Structures ◽  
Average Increase ◽  
External Reinforcement ◽  
Strength And Ductility

The innovations strengthening building structures are important topics. Failure in structures such as beams and columns due to time, re-functions of a building, even initial design errors that are weak or lack the safety factor of a building structure. External reinforced concrete beams are one of the beams currently being developed. It is a concrete block with reinforcement of steel reinforcement on the outer (external) of the beam. This study aims to determine the index of increasing beam strength and ductility after retrofitting external steel reinforcement, which has the dimension of beams 15 x 15 x 100 cm, repeating 12 pcs, with external reinforcement each 6 pcs 2Ø6 and 3Ø6. The results from this study are an increasing the index of beam flexural strength after retrofit with external steel reinforcement. Meanwhile, beams after retrofit with 2Ø6 external steel have an average increase index of 1.25 and 1.21 while for external steel 3Ø6 are 1.29 and 1.60 respectively. The ductility depends on the value of ultimate load and maximum deflection that occurs, where the ductility value for the comparison of each specimen experiences a reduction in the average ductility value with 2Ø6 external steel which is 37.74% and 70.95% while with 3Ø6 external steel is 61,65% and 60.62%. Berbagai inovasi upaya peningkatan kekuatan struktur bangunan telah menjadi bahasan yang penting. Kegagalan pada struktur seperti balok dan kolom karena umur, alih fungsi suatu bangunan, bahkan kesalahan desain awal yang lemah atau kurang memenuhi faktor keamanan suatu struktur bangunan. Balok beton bertulangan eksternal adalah salah satu balok yang sedang dikembangkan pada saat ini, yaitu balok beton dengan perkuatan tulangan baja di sisi terluar (eksternal). Penelitian ini bertujuan untuk mengetahui indeks peningkatan kekuatan balok dan daktilitas setelah dilakukan perbaikan menggunakan tulangan baja eksternal, dengan dimensi balok 15 × 15 × 100 cm berulang 12 buah, penambahan tulangan baja eksternal masingmasing 6 buah 2Ø6 dan 3Ø6. Hasil yang didapat dari penelitian ini adalah indeks peningkatan kekuatan lentur balok setelah dilakukan perbaikan menggunakan tulangan baja eksternal. Dimana balok setelah dilakukan perbaikan dengan baja eksternal 2Ø6 memiliki indeks peningkatan rata-rata 1,25 dan 1,21 sedangkan untuk baja eksternal 3Ø6 masing-masing 1,29 dan 1,60. Daktilitas tergantung dari nilai beban ultimit dan lendutan maksimum yang terjadi, dimana nilai daktilitas untuk perbandingan tiap benda uji mengalami reduksi nilai daktilitas rata-rata dengan baja eksternal 2Ø6 yaitu sebesar 37,74% dan 70,95% sedangkan dengan baja eksternal 3Ø6 sebesar 61,65% dan 60,62%.

Sign in / Sign up

Export Citation Format

Share Document