Subscribe to the gold package and get unlimited access to Shamra Academy
Register a new userMasonry arches strengthened by FRP strips
الأقواس الحجرية المقواة بشرائح من البوليميرات المسلحة بالألياف
1288
3 35
0
(
0
)
Added by
Aِl-Baath University ورقة بحثية
Publication date
2016
fields
Structural Engineering
and research's language is
العربية
Authors
بيلسان محمد( باحث )
Created by
Shamra Editor
Ask ChatGPT about the research
من تحليل النتائج التجريبية لأهم الاختبارات التي أجريت على الأقواس الحجرية المقواة على السطح الداخلي أو الخارجي بشرائح من البوليميرات المسلحة بالألياف؛ تبين أن استخدام الألياف يمنع الانهيار الهش النموذجي الممكن حدوثه في الأقواس العادية نتيجة لتشكل أربعة من المفاصل اللدنة، حيث نلمس في الأقواس المقواة (وفقاً لمواضع و كمية التسليح) وجود ثلاثة آليات ممكنة للانهيار، نوقشت النماذج المفترضة لآليات الانهيار، و قورنت النتائج النظرية التي تعطهيا مع النتائج التجريبية المدروسة لبيان مدى التوافق. أظهرت الدراسة التحليلية لنتائج الاختبارات أن التقوية بالألياف تسبب زيادة في المقاومة و المطاوعة للأقواس المقواة، و لكن لابد من إيلاء أهمية أكبر لتوزع شرائح التسليح و عرضها و الارتباط بينها و بين الحجر للوصول إلى تقوية مثالية.
Analysis of The results for one of the most important experimental tests on masonry arches strengthened at their extrados or at their intrados by fiber reinforced polymer (FRP)strips;shows that the presence of the fibers prevents the brittle collapse that occur in plain arch because of formation of four hinges, therefore (depending on position and amount of reinforcement) in strengthened arches, there are three possible mechanisms : 1- masonry crushing , 2- detachment of fibers, and 3- sliding along a mortar joint due to the shear stresses. Some analytical approaches describing these mechanisms are discussed and a comparison between the theoretical values that give and the experimental results was performed to show the agreements , according to analytical study of the experimental results strengthening by fibers enhances the strength and ductility of strengthened arches, the width of strips and the bond between them and masonry are so important to perform optimum strengthening.
References used
Schwegler, G. (1995b)" Seismic strengthening of unreinforced masonry building with carbon fibers" Rep. of Federal Institute of Technology , Zurich, Switzerland
Triantafillou, T. C. (1998a) " Strengthening of masonry structures using epoxy bonded FRP laminates. " J. Compos. For Constr., ASCE, 2(2), 96-104
Triantafillou, T. C. (1998b) " Strengthening of masonry structures using epoxy bonded FRP laminates". Errata J. Compos. For Constr., ASCE, 2(4), 203
rate research
Read More
It is well known that arch is a main part of the historical structures. Therefore, many techniques are used to strengthen these arches. In this paper, Fiber Reinforced Polymer (FRP) is used to reinforce the arch under vertical loads. Materially Non-L
inear Analysis (MNLA) is performed to demonstrate the behavior of the arch with and without the FRP.
On the other hand, the effect of FRP lamina thickness and length is undertaken in this research. This paper shows that a small amount of the FRP to some local areas can enhance the ultimate strength of the arch significantly.
Fiber reinforced polymer (FRP) plates have gained popularity in the strengthening of reinforced concrete (RC) members due to the high strength to weight ratio, the ease of installation and low maintenance costs compared to other systems such as steel
plates. Also, external bonding of fiber reinforced polymer (FRP) plate has been proven to be an effective method to strengthen and damage RC structures. However, not much attention has been given to the long-term behavioral aspects of FRP-strengthened RC members. It is difficult to accurately predict the long-term deflection, crack width and behavior of FRP-strengthened RC members.
This study presents a method for predicting the deflections at any time of the service life of normal and high strength concrete structures, loaded at any age, creep coefficient and shrinkage strain and the participation of the compressive steel for RC beams, and for RC beams strengthened with FRP plates.
The accurate prediction of deflections is a complex problem which requires the use of non-linear and time-dependent analytical methods. These methods are, in general, time consuming and require great effort[6-13]. However, at the design stage, simple but reliable methods which take into account the most important parameters influencing the long-term deflections may be very useful to adequately design the structure. For that purpose, many simplified methods have been developed [1-2-3-4-14]. Equations have been programmed to access the method combines the simplicity and accuracy and provides valuable information about the influence of each parameter on the increasing deflections with time.
The analytical values are compared to the experimental results from some existing papers [8-9], and to the results obtained from ACI code [1]. It is found that the analytical method is in a good agreement with the experimental results from some existing papers
[8-9].
Most existing structures are not designed with cod
requirements to meet seismic risk, Therefor methods for
strengthening and stiffening existing buildings are important .
This study is comparing between strengthening by adding shear
wall or by ad
ding steel bracing.X -V
The study shows the importance of using steel bracing system
that is excellent approach for strengthening and stiffening
existing buildings with small increase in mass ,the study also
approved that the constant value of R(response factor)(as
mentioned in the Syrian code and UBC97) is not completely
correct.
Our Paper is a laboratory modeling research to evaluate the efficiency of finite element model in emulation the behavior of R.C. beams with shear deficiencies (ultimate load, mechanism of cracking and failure, load-deflection behavior) strengthened w
ith GFRP strips.
We tested nine R.C. beams 200x30x16 cm in three groups, the first consists of three R.C.beams for comparing, the second consists of three strengthened R.C. beams with two sides vertical GFRP strips, and the third also consists of three strengthened R.C. beams with two sides inclined (45°) GFRP strips.
We modeled these beams by advanced finite element program Ansys10, and we get results agreed with our laboratory study.
In the last two decades, the use of advanced composite materials such
as Fiber Reinforced Polymers (FRP) in strengthening reinforced
concrete (RC) structural elements has been increasing. Research and
design guidelines concluded that externally bo
nded FRP could increase
the capacity of RC elements efficiently. However, the linear stressstrain
characteristics of FRP up to failure and lack of yield plateau have
a negative impact on the overall ductility of the strengthened RC
elements. Use of hybrid FRP laminates, which consist of a
combination of either carbon and glass fibers, or glass and aramid
fibers, changes the behavior of the material to a non-linear behavior.
This paper aims to study the performance of reinforced concrete beams
strengthened by hybrid FRP laminates.
Log in to be able to interact and post comments
comments
Fetching comments
Sign in to be able to follow your search criteria
