Capacity Calculation on Reinforced Concrete Beams Strengthened by Externally Prestressed Transverse Tensioning Method

2013 ◽  
Vol 671-674 ◽  
pp. 636-641
Author(s):  
You Zhi Tong ◽  
Tian Wen Wang

Eight reinforced concrete beams (six externally reinforced and two contrast beams) were tested under the primary or secondary load experiment. According to the test results, the existing formulas and specifications were applied to make calculations on reinforced beams. Besides, comparisons were made between test and calculation value, the differences were pointed out and improvement measures were proposed. Comparisons were made between test and calculation value on normal section flexural bearing capacity of reinforced concrete beams strengthened by externally prestressed transverse tensioning method and they are in good agreement.

2013 ◽  
Vol 671-674 ◽  
pp. 430-436
Author(s):  
Jin Jun Liu ◽  
Tian Wen Wang

Eight reinforced concrete beams (six externally reinforced and two contrast beams) were tested under primary or secondary load experiment. According to the test results, the existing specifications were applied to make calculations on short-term deflection which leaded to a large error. The secondary effect should be considered on calculating the deflection. Therefore, comparisons were made between the improved calculated value and test value on deflections of reinforced concrete beams strengthened by externally prestressed transverse tensioning method and they are in good agreement.


2013 ◽  
Vol 798-799 ◽  
pp. 374-377
Author(s):  
Shuan Jiang

The ultimate tendon stress is the key to calculation of flexural capacity in reinforced concrete beam prestressed with external FRP tendons (RCBPEFT). Based on the theory of equivalent plastic hinge zone, the general formulas for calculating the ultimate tendon stress increment and ultimate tendon stress in RCBPEFT are therefore proposed. Comparisons indicate that the predictions are in good agreement with the test results.


2020 ◽  
Vol 63 (4) ◽  
pp. 87-98
Author(s):  
Damir Zenunović ◽  
Danijel Ružić

This paper presents an experimental program of initial testing of reinforced concrete beams using bars and textiles carried out with an aim of comparative analysis of the behaviour of reinforced concrete beams using textiles in relation to conventional reinforced beams. Alkalineresistant glass fibre textile meshes were used for the purposes of the experiment. An experiment setting is described and obtained test results are presented in this paper. An analysis of the obtained results is presented at the end of the paper. The experimental program demonstrated that adding textile mesh, besides improvement of the durability of the protective layer of concrete, can improve the load-bearing capacity and ductility of reinforced concrete beams. There is still an issue related to workability of concrete in textile reinforced beams and achievement of full adhesion between textile mesh and concrete. At the end of the paper, a suggestion was given about semi-prefabricated reinforced concrete beams using reinforced bars and textiles.


2011 ◽  
Vol 243-249 ◽  
pp. 1461-1465
Author(s):  
Chuan Min Zhang ◽  
Chao He Chen ◽  
Ye Fan Chen

The paper makes an analysis of the reinforced concrete beams with exterior FRP Shell in Finite Element, and compares it with the test results. The results show that, by means of this model, mechanical properties of reinforced concrete beams with exterior FRP shell can be predicted better. However, the larger the load, the larger deviation between calculated values and test values. Hence, if more accurate calculation is required, issues of contact interface between the reinforced concrete beams and the FRP shell should be taken into consideration.


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.


2010 ◽  
Vol 37 (8) ◽  
pp. 1045-1056 ◽  
Author(s):  
Christopher Suffern ◽  
Ahmed El-Sayed ◽  
Khaled Soudki

This paper reports experimental data on the structural performance of disturbed regions in reinforced concrete beams with corrosion damage to the embedded steel stirrups. A total of 15 reinforced concrete beams were constructed and tested. The test beams were 350 mm deep, 125 mm wide, and 1850 mm long. The beams were tested in three-point bending under a simply supported span of 1500 mm. Nine beams had the embedded stirrups subjected to accelerated corrosion. The test variables were the corrosion damage level and the shear span-to-depth ratio. The test results indicated that the corroded beams exhibited reduced shear strength in comparison to the uncorroded control specimens. The shear strength reduction was up to 53%. Furthermore, the reduction in shear strength due to the corrosion was found to be greater at smaller shear span-to-depth ratios.


2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
Chunyu Fu ◽  
Dawei Tong ◽  
Yuyang Wang

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.


2012 ◽  
Vol 503-504 ◽  
pp. 832-836
Author(s):  
Hong Quan Sun ◽  
Jun Ding

This paper gives the influences of the coarse aggregate size on the cracks of the beam with different aggregate sizes under static loads. The coarse aggregate sizes are ranked into three classes: small size (4.75mm ~ 19mm), big size (19mm ~ 37.5mm) and mixed size (4.75mm ~ 37.5mm). The developments of cracks of three reinforced concrete beams with the different of coarse aggregate sizes under the static loads are researched. The results show that under the action of the same loads, The reinforced concrete beams with the big aggregate size and mixed aggregate size have almost the same maximum crack width, while the maximum crack width of the beam with small aggregate size is less than formers. Using fractal theory, the fractal dimension of the cracks is studied. The result shows that the aggregate sizes have significant effect to the cracks on the reinforced beams.


2011 ◽  
Vol 243-249 ◽  
pp. 621-624
Author(s):  
Gui Bing Li ◽  
Yu Gang Guo

Bonding fiber reinforced polymer (FRP) laminates to the tension face of RC members has been proven to be an effective method to improve the flexural strength. However, structural members are not only needed to have adequate strength, but also to have adequate performance of deformation at service load levels. To evaluate the deflection of externally FRP-strengthened RC beams, a total of 18 RC beams, including 16 beams strengthened with CFRP laminate under different preload levels and 2 control beams, were tested. Based on the assumption that the section of the beam behaves a tri-linear moment-curvature response characterized by pre-crack stage, post-crack stage and failure stage and the test results, this paper presents a modified model to evaluate the deflection of CFRP-strengthened RC beams. The present modified model was verified by the similar test results, and shows a good agreement with the test results.


2011 ◽  
Vol 71-78 ◽  
pp. 815-817 ◽  
Author(s):  
Jiong Feng Liang ◽  
Ze Ping Yang ◽  
Zhi Ming Qiu

The mechanical properties of high-strength reinforced concrete beams strengthened with FRP ( fiber reinforce polymer) are further investigated theoretically including it s failure mechanism and loadability,based on earlier theoretical works on RC beams. And the correlation equation of flexural capacity on the cross section of high-strength reinforced concrete beams strengthened with FRP is deduced according to different types of failure.The correlation equation is shown to be in good agreement with the experimental results, which can be referred to engineering application.


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