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%.

scholarly journals DUCTILITY RESPONSE OF HYBRID FIBRE REINFORCED CONCRETE BEAMS

2018 ◽  
pp. 174-179 ◽  
Author(s):  
Eswari Natarajan
Keyword(s):  
Reinforced Concrete ◽  
Ultimate Load ◽  
Concrete Beams ◽  
Volume Fraction ◽  
Fibre Volume ◽  
Reinforced Concrete Beams ◽  
Fibre Reinforced Concrete ◽  
Hybrid Fibre ◽  
Service Load ◽  
Strength And Ductility

Abstract: The effect of fibre content on the Strength and ductility behaviour of hybrid fibre reinforced concrete (HFRC) beams having different fibre volume fractions was investigated. The parameters of this investigation included service load, ultimate load, service load deflection, ultimate load deflection, crack width, deflection ductility and energy ductility. The fibre volume fraction (Vf) ranged from 0.0 to 2.0 percent. Steel and polyolefin fibres were combined in different proportions and their impact on the above parameters was studied. The ductile response of hybrid fibre reinforced concrete beams was compared with that of control beam. The test results show that addition of 2.0 percent by volume of hybrid fibres improve the strength and ductility appreciably. Empirical expressions for predicting the strength and ductility of hybrid fibre reinforced concrete (HFRC) are proposed based on regression analysis. A close agreement has been obtained between the predicted and experimental results.

scholarly journals Strength and Ductility of Bubbled Wide Reinforced Concrete Beams with Diverse Types of Shear Steel Plates

2018 ◽  
Vol 7 (4.20) ◽  
pp. 502 ◽  
Author(s):  
Amer Mohamed Ibrahim ◽  
Ahmed Abdullah Mansor ◽  
Wissam D. Salman ◽  
Mohammed Jaafar Hamood
Keyword(s):  
Reinforced Concrete ◽  
Ultimate Load ◽  
Concrete Beams ◽  
Good Alternative ◽  
Reinforced Concrete Beams ◽  
Steel Plates ◽  
Cross Sectional ◽  
Service Load ◽  
Different Types ◽  
Strength And Ductility

This paper presents an experimental investigation on the strength of bubbled wide reinforced concrete beams with different types of shear steel plates. Eight specimens with dimensions of 215x560x1800mm were investigated. The studied variables deal with replacement of 10mm stirrups diameter stirrups spaced at 125mm by shear steel plates having equivalent cross-sectional area for stirrups at mid legs height with circular opening of different thicknesses (3, 4 and 5mm). Four specimens were without any bubbles and the others with bubbles. This study showed that the shear steel plates is a good alternative for replacing the stirrups and gives increasing in yield, ultimate load and deflection (at service load) with 5% , 15% and 9% on the average when using the bubbles. Without using bubbles, the aspect ratio of shear steel plates bounded between the boundaries 4.5 to 8 gave increased the ductility by 36%. Using the bubbles in specimens was decreased 4.7% from the total weight of specimens. ACI 318-14(1) and EC 2(2) codes give a predicted deflection more than that obtained from experimental results by 16% on the average and by 24% when using bubbles.    

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.

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.

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 Flexural Behavior of Fiber Reinforced Self-Compacting Rubberized Concrete Beams

2020 ◽  
Vol 26 (2) ◽  
pp. 111-128
Author(s):  
Tamara M. Hasan ◽  
Ahmed S. Ali
Keyword(s):  
Reinforced Concrete ◽  
Ultimate Load ◽  
Steel Fiber ◽  
Concrete Beams ◽  
Monotonic Loading ◽  
Reinforced Concrete Beams ◽  
Flexural Behavior ◽  
Repeated Loading ◽  
Fiber Reinforced ◽  
Waste Tire

The massive growth of the automotive industry and the development of vehicles use lead to produce a huge amount of waste tire rubber. Rubber tires are non-biodegradable, resulting in environmental problems such as fire risks. In this search, the flexural behavior of steel fiber reinforced self-compacting concrete (SFRSCC) beams containing different percentages and sizes of waste tire rubbers were studied and compared them with the flexural behavior of SCC and SFRSCC. Micro steel fiber (straight type) with aspect ratio 65 was used in mixes. The replacement of coarse and fine aggregate was 20% and 10% with chip and crumb rubber. Also, the replacement of limestone dust and silica fume was 50%, 25%, and 12% with ground rubber and very fine rubber, respectively. Twelve beams with small-scale (L=1100mm, h = 150mm, b =100mm) were tested under two points loading (monotonic loading). Fresh properties, hardened properties, load-deflection relation, first crack load, ultimate load, and crack width were investigated. Two tested reinforced concrete beams from experimental work were selected as a case study to compare with the results from ABAQUS program (monotonic loading). These two reinforced concrete beams were simulated as a parametric study under repeated loading using this finite element program. The results showed that the flexural behavior of SFRSCC beams containing rubber was acceptable when compared with flexural behavior of SCC and SFRSCC beams (depended on load carrying capacity). Cracks width was decreased with the addition of steel fibers and waste tires rubber.  An acceptable agreement can be shown between the results of numerical analysis and the results obtained from experimental test (monotonic loading). Insignificant ultimate load differences between the results of monotonic loading and repeated loading                                                                                                                                                                                           

scholarly journals Experimental Investigation of Using PET Wastes as Tension Bars in Reinforced Concrete Beams

2019 ◽  
Vol 27 (1) ◽  
pp. 247-261
Author(s):  
Abass Oda Dawood ◽  
Hamsa Mahir Adnan
Keyword(s):  
Reinforced Concrete ◽  
Ultimate Load ◽  
Failure Load ◽  
Concrete Beams ◽  
Reference Beam ◽  
Reinforced Concrete Beams ◽  
Additional Layer ◽  
Steel Bar ◽  
Bonding Failure ◽  
Ultimate Failure

This research is aimed to study the possibility of recycled the PET wastes by forming the PET wastes as plastic semi-bars and used it as tension bars in simply supported reinforced concrete beams . Twelve beams specimens with dimension of (150*200*1400) mm are casted and tested to monitoring the effecting of these wastes as tension bars on the strengths and serviceability of reinforced concrete beams. The mechanical properties (compressive, splitting tensile and flexural strength) are evaluated in which specimens tested in age of 28 days. The tests results showed that all presented plastic semi-bars are failed except one case in which the deformed steel bar are used with additional layer of PET bottle cut into two parts which showed an increment in ultimate failure load and deflection of  3.03 % and 213.83 % respectively, larger than the reference beam specimens. Negatively effect of PET semi-bar on ultimate load of beams is due to bonding failure between PET bars and surrounding concrete, which made the PET bars as voids or weak region within beam cross section.

scholarly journals The effects of steel reinforcement corrosion on the flexural capacity and stiffness of reinforced concrete beams

2021 ◽  
Author(s):  
Timothy A Joyce
Keyword(s):  
Reinforced Concrete ◽  
Concrete Beams ◽  
Chloride Ion ◽  
Steel Reinforcement ◽  
Reinforced Concrete Beams ◽  
Reinforcement Corrosion ◽  
Flexural Capacity ◽  
Ion Content ◽  
Sharp Drop ◽  
Low Degrees

This study is an attempt to derive a relationship between steel reinforcement corrosion and the coinciding loss of flexural strength. The corrosion of the steel was isolated in the flexural region in order to eliminate contributions from stirrup corrosion and loss of bond within the development length. It was determined that the flexural capacity of reinforced concrete beams decreased as the rate of corrosion increased. In addition to the study of flexural capacity, the prediction of the flexural behaviour of corroded beams was studied through the stiffness effects of reinforcement corrosion. The stiffness study indicated a sharp drop in stiffness at relatively low degrees of corrosion, followed by a slower decline at increasing levels of corrosion. Mass loss, crack width and chloride ion content were examined as indicators of degree of corrosion. These relationships are an essential step in developing an effective model for the performance of corroded reinforced concrete beams in the future.

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