Retrofitting of RC Beams: A Review

2016 ◽  
Vol 857 ◽  
pp. 206-211
Author(s):  
John P. Joseph ◽  
Anitta Jose ◽  
George M. Varghese

Reinforced concrete (RC) is the most popular building material in the construction industry. It is a composite material in which low tensile strength and ductility of concrete are counteracted by the inclusion of reinforcement having higher tensile strength and ductility. The RC based structures are required to be replaced after their life time. Complete replacement will be a huge financial burden and might certainly be a waste of natural resources when upgrading or strengthening is an adoptable alternative. Strengthening can be achieved through retrofitting. The meaning of retrofitting is addition of new technology, components, accessories or features to older systems. Retrofitting may be required when the structure needs to be used for a purpose dealing with more load compared to design loads. It may also be used where old structures are needed to be upgraded. This paper is focused on the retrofitting of simply supported RC beams. Various materials like polymers, cementitious composites, steel sections etc. are used for retrofitting of RC beams. For the addition of these new materials to the existing ones, various techniques are used. This paper is a review of the materials and techniques used in retrofitting process of RC beams in existing buildings. The effectiveness of each material and technique is also reviewed.

Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 2809
Author(s):  
Md. Akter Hosen ◽  
Fadi Althoey ◽  
Mohd Zamin Jumaat ◽  
U. Johnson Alengaram ◽  
N. H. Ramli Sulong

Reinforced concrete (RC) structures necessitate strengthening for various reasons. These include ageing, deterioration of materials due to environmental effects, trivial initial design and construction, deficiency of maintenance, the advancement of design loads, and functional changes. RC structures strengthening with the carbon fiber reinforced polymer (CFRP) has been used extensively during the last few decades due to their advantages over steel reinforcement. This paper introduces an experimental approach for flexural strengthening of RC beams with Externally-Side Bonded Reinforcement (E-SBR) using CFRP fabrics. The experimental program comprises eight full-scale RC beams tested under a four-point flexural test up to failure. The parameters investigated include the main tensile steel reinforcing ratio and the width of CFRP fabrics. The experimental outcomes show that an increase in the tensile reinforcement ratio and width of the CFRP laminates enhanced the first cracking and ultimate load-bearing capacities of the strengthened beams up to 141 and 174%, respectively, compared to the control beam. The strengthened RC beams exhibited superior energy absorption capacity, stiffness, and ductile response. The comparison of the experimental and predicted values shows that these two are in good agreement.


2012 ◽  
Vol 622-623 ◽  
pp. 323-329
Author(s):  
Ebtisam F. Abdel-Gwad ◽  
A. Shahenda ◽  
S. Soher

Friction stir welding (FSW) process is a solid state welding process in which the material being welded does not melt or recast. This process uses a non-consumable tool to generate frictional heat in the abutting surfaces. The welding parameters and tool pin profile play major roles in deciding the weld quality. In this investigation, an attempt has been made to understand effects of process parameters include rotation speeds, welding speeds, and pin diameters on al.uminum weldment using double shoulder tools. Thermal and tensile behavior responses were examined. In this direction temperatures distribution across the friction stir aluminum weldment were measured, besides tensile strength and ductility were recorded and evaluated compared with both single shoulder and aluminum base metal.


2007 ◽  
Vol 23 ◽  
pp. 123-126
Author(s):  
Radu L. Orban ◽  
Mariana Lucaci

This paper investigates the effect of Fe, Cr and B additions, in small proportions, as alloying elements in Ni3Al with the purpose to reduce its intrinsic fragility and extrinsic embrittlement and to enhance, in the same time, its mechanical properties. It represents a development of some previous research works of the authors, proving that Ni3Al-Fe-Cr-B alloys obtained by reactive synthesis (SHS) starting from Mechanically Alloyed powder mixtures have superior both room temperature tensile strength and ductility, and compression ones at temperatures up to 800 °C, than pure Ni3Al. These create premises for their using as superalloys substitutes.


2017 ◽  
Vol 123 ◽  
pp. 285-294 ◽  
Author(s):  
Dongyue Li ◽  
Chengxin Li ◽  
Tao Feng ◽  
Yidong Zhang ◽  
Gang Sha ◽  
...  

1981 ◽  
Vol 12 ◽  
Author(s):  
A. Kolb-Telieps ◽  
B.L. Mordike ◽  
M. Mrowiec

ABSTRACTCu-Nb composite wires were produced from powder, electrolytically coated with tin and annealed to convert the Nb fibres to Nb 3Sn. The content was varied between 10 wt % and 40 wt %. The superconducting properties of the wires were determined. The mechanical properties, tensile strength, yield strength and ductility were measured as a function of volume fraction and deformation over a wide temperature range. The results are compared with those for wires produced by different techniques.


Author(s):  
Majahar M. Baraskar ◽  
Pranil Shetake ◽  
Prof. V. M Bogar ◽  
Dr. Y. M Ghugal

Steel is used in construction industry due to its hardness and tensile strength. Cold formed steel is type of steel which is manufactured at lower temperature. Cold form steel became more popular in twentieth century in construction industry due to its high strength to weight ratio and post-buckling strength. The purpose of this study is to study the behavior of cold-formed steel sections of different shapes but of same cross sectional area for compressive loading. Effect of lips within same cross sectional area, effect of perforation and shape stiffener is evaluated on different sections as channel section, Z section and hat section. Eigen value buckling analysis was carried out to on twelve different models to obtain the buckling load and failure pattern. ANSYS WORKBENCH software was used for numerical simulation of sections. I.S. 801:1975 has been taken under consideration wherever required. Based upon the results, optimum section in each of cases as with lips, without lips and perforated amongst all three sections is suggested. Effect of shape stiffeners provided by previous researcher P. Manikandan on solid sections is evaluated to check its suitability with perforated sections.


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