Analisis Pola Kegagalan Balok Sistem Rangka dengan Perkuatan di Daerah Tumpuan

2020 ◽  
Vol 24 (1) ◽  
pp. 17-23
Author(s):  
Mardis Darwis ◽  
Rudy Djamaluddin ◽  
Rita Irmawaty ◽  
Astiah Amir

The previous research of using truss system reinforcement in the beam without concrete (BTR) in the tension zone causes a decrease in flexural capacity due to the failure in the area near the support. Therefore, it is necessary to add tensile reinforcement in the support zone. This study aims to analyze the ultimate capacity of the truss system concrete beam strengthened with tensile reinforcement and to analyze the effect of tensile reinforcement in support zone due to crack pattern. This study was conducted experimentally in the laboratory. The dimension of truss reinforced concrete specimens are 15 cm x 20 cm x 330 cm that added tensile reinforcement with three types of length, they are BTRP 40D, BTRP 50D, and BTRP 60D, where D (13 mm) is diameter of tensile reinforcement. The flexural test is carried out by monotonic static loading. The results showed that tensile reinforcement in BTRP 40D was not able to carry the ultimate capacity due to premature failure in the support zone. while BTRP 50D and BTRP 60D specimens can enhance the ultimate capacity without facing premature failure in the support zone. The tensile reinforcement of 60D has the highest ultimate capacity because it can carry the biggest loads and minimum crack pattern.

2019 ◽  
Vol 81 (3) ◽  
Author(s):  
Chun-Chieh Yip ◽  
Jing-Ying Wong ◽  
Ka-Wai Hor

Software simulation enables design engineers to have a better picture of possible structural failure behaviour and determine the accuracy of a design before the actual structural component is fabricated. Finite element analysis is used to simulate the behaviour of the reinforced concrete beam under the flexural test. During the flexural test, results are recorded for both simulation and experimental tests. By comparing the results, beam displacement, crack patterns, and failure modes can be studied with better accuracy. The accuracy percentage for yield load and ultimate load between the two tests results were 94.12 % and 95.79 %, respectively, whereas the accuracy percentage for elastic gradient before the yielding stage was 81.08 %. The behaviour between simulation and laboratory models described is based on crack pattern and failure mode. The progression of von Mises (VM) stresses highlighted the critical areas of the reinforced concrete beam and correlation between the experimental specimen, in terms of flexural cracks, shear cracks, yielding of tension reinforcement, and the crushing of concrete due to compressive stress. This paper concludes that simulation can achieve a significant accuracy in terms of loads and failure behaviour compared to the experimental model.


2017 ◽  
Vol 889 ◽  
pp. 270-274
Author(s):  
Noridah Mohamad ◽  
Wan Inn Goh ◽  
Abdul Aziz Abdul Samad ◽  
A. Lockman ◽  
Anas Alalwani

This paper presents the structural behaviour of reinforced concrete beam embedded with high density polyethylene balls (HDPE) subjected to flexural load. The HDPE balls with 180 mm diameter were embedded to create the spherical voids in the beam which lead to reduction in its self-weight. Two beam specimens with HDPE balls (RC-HDPE) and one solid beam (RC-S) with dimension 250 mm x 300 mm x 1100 mm were cast and tested until failure. The results were analysed in the context of its ultimate load, load-deflection profile, and crack pattern and failure mode. It was found that the ultimate load of RC-HDPE was reduced by 32% compared to RC-S beam while the maximum deflection at its mid span was increased by 4%. However, RC-HDPE is noticed to be more ductile compared to RC-S beam. Both types of beams experienced flexure cracks and diagonal tension cracks before failure.


Author(s):  
Mustaqqim Abdul Rahim ◽  
Amirah Syazwani Karuddin ◽  
Afizah Ayob ◽  
Ahmad Nur Aizat Ahmad ◽  
Shahiron Shahidan ◽  
...  

The reinforced concrete is one of the widely used structural materials which have its own major advantages and disadvantages. Its behaviour when provided in various positions in the structural elements like compression, tension, and shear zones has significant impact. Since the concrete is excellent in the compression behaviour, and only a nominal performer in the tension behaviour, steel reinforcement are provided in required zones where tension occurs. Thus in a bending member, below the neutral axis, that is at the tension zone, the concrete acts only as a interface medium between reinforcement that carrying the tension and the concrete above neutral axis carrying compression forces. This concrete is also called as sacrificial concrete. Thus in order to efficiently use the concrete falls under the tension zone, the concrete can be swapped with any suitable lighter or cheaper material or the concrete may be strengthened to carry tensile stresses. In this present study, the concrete below neutral axis is replaced with lightweight ‘aerocon’ block cubes of 8 cu.cm and 64 cu.cm by 20% of volume of concrete and in another specimen, steel fibres are added in the concrete that are below neutral axis by 2% and 3% by weight to improve the local tensile strength of concrete as material The results obtained shows that the aerocon cubes replaced specimens has equivalent performance of the control specimen and the steel fibre added specimen had superior deflection and crack performance than the control specimen.


2015 ◽  
Vol 773-774 ◽  
pp. 1022-1026 ◽  
Author(s):  
Md Noor Noorsuhada ◽  
Ibrahim Azmi ◽  
Muhamad Bunnori Norazura ◽  
Mohd Saman Hamidah ◽  
Mat Saliah Soffian Noor ◽  
...  

Fatigue crack of the precast reinforced concrete beam under repetition loading is vital to be examined. Reinforced concrete structures exposed to excessive repetition loading could lead to the failure of the structures. In order to examine the active fatigue crack, the reinforced concrete beams were subjected to three-point repetition maximum loading. Eight phases of maximum fatigue loading with sinusoidal wave, frequency of 1 Hz and 5000 cycles for each phase were performed on the reinforced concrete beams. The inspection was carried out with visual observation of the crack pattern and acoustic emission technique for each load phase. The signal strength of acoustic emission was investigated. It is found that the signal strength of acoustic emission and crack pattern of the reinforced concrete beam subjected to repetition loadings showed promising results for structural health monitoring.


2009 ◽  
Vol 79-82 ◽  
pp. 1141-1144
Author(s):  
Jiong Feng Liang ◽  
Ze Ping Yang ◽  
Lan Lan Yan

Based on earlier theoretical works on RC beams ,the mechanical properties of steel reinforced concrete beams strengthened with FRP(fiber reinforce polymer) are further investigated theoretically including theirs failure mechanism and loadability. According to the design method of reinforced concrete beam strengthened with FRP, steel reinforced concrete beam strengthened with FRP mainly can have three kinds of destruction patterns: the first case is the tensile steel yield, the tensile shaped steel yield, the FRP are put off, the compressive zone’s concrete has not crushed; the second case is the tensile steel yield, the tensile shaped steel yield, the FRP are put off; the compressive zone’s concrete has crushed; the last case is the tensile steel yield, the tensile shaped steel yield, the FRP are not put off, the compressive zone’s concrete has crushed. The second case is discussed in this paper.Based on the different position of middle axle and steel, steel concrete beams strengthened with FRP include: middle axle through the steel web, and not through the steel and just in steel compression flange . Aim at these three kind of situations, the stress are analysed. According to the stress patterns of steel reinforced concrete beams strengthened with FRP and different position between neutral axis and steel, the discriminant formula of the boundary destroys and the formula of cross-section flexural capacity calculation are put forward by using limit equilibrium theory.The formula is expressed clearly, simple and easy to use.The depth of compressive region is given in view of different failure types.


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