Mehrdad Mashayekh Far
Abstract
Iran is one of the countries where the probability of earthquakes is very high, and earthquakes have always caused numerous human and financial losses and the loss of national capitals. Therefore, many researches on the phenomenon of earthquakes and increasing the resistance of buildings as well as the ...
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Iran is one of the countries where the probability of earthquakes is very high, and earthquakes have always caused numerous human and financial losses and the loss of national capitals. Therefore, many researches on the phenomenon of earthquakes and increasing the resistance of buildings as well as the vulnerability of buildings have been done in countries. A look at the damages caused by past earthquakes shows that a high percentage of the existing buildings do not have sufficient and acceptable resistance against earthquakes for various reasons and often meet the requirements of the new codes.They do not, therefore, the need to strengthen these buildings in order to face the side forces with reliable, easy and fast resistance methods is felt. On this basis, in the current research, considering the importance of the subject, while presenting the seismic evaluation stages of the structures, an effort has been made to explain the different and effective methods of strengthening the reinforced concrete structures according to the type of application. More efficient and reliable methods will be
behzad ayoobi
Abstract
One of the challenges of using reinforced concrete structures is the corrosion of reinforcements in aggressive and corrosive environments such as offshore structures, stairs, etc., which will eventually lead to the destruction of concrete structures. To solve the corrosion problem in this category of ...
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One of the challenges of using reinforced concrete structures is the corrosion of reinforcements in aggressive and corrosive environments such as offshore structures, stairs, etc., which will eventually lead to the destruction of concrete structures. To solve the corrosion problem in this category of structures, experts turned to the use of rebars with epoxy coating as a suitable alternative to conventional rebars. Most FRP rebars on the market today are made of high-performance continuous fibers such as glass, carbon and aramid, which are embedded in a polymer substrate by various composite production methods. FRP amplifiers are commonly used in various forms in the form of networks, rebars, textiles or cables. In this research, the numerical behavior of FRP hybrid reinforced concrete compression members and its modeling under concentric loading is investigated. All modeling is performed in ABAQUS finite element software and is evaluated using nonlinear analysis.
reza shirvani shiri; morteza jamshidi; meysam memar
Volume 3, Issue 9 , December 2021, , Pages 11-31
Abstract
Shorter columns absorb more seismic force than conventional columns due to their higher stiffness. For this reason, short columns are seriously damaged during an earthquake and sometimes cause damage to the entire structure. It has been shown that when short columns are displaced as much as long columns, ...
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Shorter columns absorb more seismic force than conventional columns due to their higher stiffness. For this reason, short columns are seriously damaged during an earthquake and sometimes cause damage to the entire structure. It has been shown that when short columns are displaced as much as long columns, they absorb more energy. As a result, this phenomenon causes shear and joint failure in the short column. In this research, using the experimental results of a short column that has been affected by lateral reciprocating loads, an attempt was made to select the most optimal form with the help of steel sheets covered in different shape patterns to be developed by scientific study. Provide design relationships for this retrofit method. For this purpose, to determine the effect of reinforcement on the short column, six different modes of installation of the proposed steel cover in Abacus software were used for finite element analysis. Also, the studied short column was subjected to reciprocating cyclic loading according to the ATC24 standard pattern. The results of this study showed that the reinforcement of the short column with integrated steel sheet is able to increase the seismic resistance of the column by 49%, but the most optimal method of reinforcement in terms of strength and volume of steel used is the reinforcement method with mesh pattern installation.
saeed radmanesh; roozbeh aghamajidi
Volume 3, Issue 2 , May 2021, , Pages 32-47
Abstract
Flexural reinforcement of reinforced concrete beams with composite materials is one of the most common methods of structural reinforcement. Composite materials have several advantages such as ease of implementation, easy access, relatively low cost, increased bearing capacity, low weight, etc., but despite ...
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Flexural reinforcement of reinforced concrete beams with composite materials is one of the most common methods of structural reinforcement. Composite materials have several advantages such as ease of implementation, easy access, relatively low cost, increased bearing capacity, low weight, etc., but despite all these advantages, the use of these materials also has disadvantages, which can be Premature and sudden bending failure in beams reinforced with these materials, which occurs due to premature rupture of composite materials or even deterioration of the joint area due to lack of attention to the stability of epoxy adhesive from the concrete surface in the tensile zone of the beam, noted. In this paper, by designing a computational program with Abacus software, 7 examples of reinforced concrete beam reinforcement design with GFRP rebar by near-surface installation method (NSM) and its integration with various FRP sheet enclosure cases taken from a This is a laboratory study, an attempt was made to prevent premature failure of the reinforced beam and to be able to use the maximum capacity of GFRP rebar. It is noteworthy that in modeling this reinforcement design with composite materials, the effect of ultimate adhesion resistance and failure or deterioration of epoxy adhesive between NSM rebar and concrete surface is important, so in this modeling of the joint area which is epoxy adhesive modeling and its behavior Has been examined. The use of this reinforcement method with four NSM rebars and FRP sheets increased the final bearing capacity by more than 60% compared to conventional reinforced concrete beams.
