scholarly journals Analisa Perilaku Pushover pada Pengujian Balok Beton Bertulang

Author(s):  
Sudarno P Tampubolon

Beams are part of the building structure that is important to consider when designing the structure. Some failures that occur in beams due to beam reinforcement are not installed such as planning/ design procedures, this problem can cause structural failure. Knowing the behavior of the beam structure due to the given load can help predict the strength of the structural beam and the comfort of the planned structure. To determine and predict the strength and comfort of the reinforced concrete beam structure due to the received load, experimental and simulation tests are carried out. VecTor2 simulation is used to predict shear, crack, and displacement forces in reinforced concrete beams when displacement loads are applied. The bond stress-slip effect (0.139) has a good effect on the strength and hysterical response of reinforced concrete beams. From the results of pushover testing and simulations, it is obtained that the ratio for load capacity ranges from 1.00-1.095. In addition, the installation of 135˚ hooks on stirrups shows that the crack behavior that occurs forms an angle of 45˚, this indicates that the bond between concrete and reinforcement is going well, this can be seen from the analogous behavior principle of reinforced concrete beams.

1991 ◽  
Vol 18 (6) ◽  
pp. 1005-1012
Author(s):  
George Akhras ◽  
John A. Fedoruk

Most computer programs developed for reinforced concrete beam design either analyze a given cross section for load capacity or offer a limited solution from which the engineer must continue toward the final design. These programs are very useful in performing many tedious calculations. However, they generally do not offer assistance in areas of design that require intuitive reasoning, experiential knowledge, rules of thumb, and sound engineering judgement. This type of heuristic knowledge has been incorporated into a prototype knowledge-based expert system for reinforced concrete beam design and detailing called BeamEx. BeamEx interacts with the user to advise and establish suitable parameters required for the comprehensive design of rectangular simply supported and continuous beams. It incorporates heuristic rules drawn from the governing Canadian codes and textbooks to design alternative suitable beams which are presented in graphical form. It is shown that a knowledge-based system approach can be used effectively in engineering design by encapsulating domain expertise in a program to complement and check the experience of the users in design. Key words: knowledge-based expert system, reinforced concrete, beams, design, detailing.


2011 ◽  
Vol 368-373 ◽  
pp. 108-113
Author(s):  
Can Liu ◽  
Bo Wu ◽  
Kai Yan Xu

This paper presents a method that using inner transverse prestressing bars to enhance the shear capacity of concrete beams, which can be used in new transformer beams to decrease the sectional dimensions. Four transversely prestressed concrete beams and one ordinary reinforced concrete beam were tested. The nonlinear finite element method was applied to analyze them, and the following conclusions can be drawn: (a) The transverse prestressing bars can efficiently increase the shear capacity and failure load of the reinforced concrete beam, the improvement effect is more obvious when exerting the prestressing force on them properly. (b) On the whole, the simulated load-deflection relationships and failure loads of the five specimens agree well with the corresponding tested load-deflection relationships and failure loads. It indicated that the FE models used in this paper predict the structural behavior of the transversely prestressed concrete beams satisfactorily. (c) From the contour of first principal stress, it can be seen that the transverse prestressing bars can efficiently enhance the shear crack resistance of the reinforced concrete beams, if the area of transversely prestressing bars is almost same, the transverse bars with smaller diameter and smaller spacing will be better. It agrees well with the test results.


Author(s):  
Elsayed Ismail ◽  
Mohamed S. Issa ◽  
Khaled Elbadry

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.


2018 ◽  
Vol 21 (13) ◽  
pp. 1977-1989 ◽  
Author(s):  
Tengfei Xu ◽  
Jiantao Huang ◽  
Arnaud Castel ◽  
Renda Zhao ◽  
Cheng Yang

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.


2012 ◽  
Vol 214 ◽  
pp. 306-310
Author(s):  
Han Chen Huang

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.


2018 ◽  
Vol 931 ◽  
pp. 379-384
Author(s):  
Yuri V. Ivanov ◽  
Yuri F. Rogatnev ◽  
Igor I. Ushakov

The paper considers the results of the experimental study of the reinforced concrete beams strengthened by carbon fiber reinforced plastics (the CFRP). Eight reinforced concrete beams of the 80x160 mm section and 1500 mm designed span have been manufactured and tested. The influence of the number of the CFRP layers (strengthening power) on bearing capacity and rigidity under the static loading of beams in the thirds of the span has been studied. The results obtained indicate the increase in bearing capacity of the reinforced beams from 24% up to 55% and the increase in rigidity by 45% for the commonly adopted limiting state, i.e. achieving ultimate deformations in concrete of the compressed zone). The paper underlines the need for using anchor devices in the form of U-shaped binders to ensure the efficiency of the given method of strengthening.


2020 ◽  
Vol 23 (9) ◽  
pp. 1934-1947
Author(s):  
Dapeng Chen ◽  
Li Chen ◽  
Qin Fang ◽  
Yuzhou Zheng ◽  
Teng Pan

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.


2020 ◽  
Vol 857 ◽  
pp. 162-168
Author(s):  
Haidar Abdul Wahid Khalaf ◽  
Amer Farouk Izzet

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.


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