NATIONAL BIBLIOGRAPHY NUMBER
Number
۱۸۰۹۴پ
LANGUAGE OF THE ITEM
.Language of Text, Soundtrack etc
per
TITLE AND STATEMENT OF RESPONSIBILITY
Title Proper
تعیین ظرفیت خمشی تیرهای بتن آرمه تقویت شده با CFRP با بهبود مکانیسم های debonding
First Statement of Responsibility
/اورنگ رنجبراقدم
.PUBLICATION, DISTRIBUTION, ETC
Name of Publisher, Distributor, etc.
: مهندسی عمران
Date of Publication, Distribution, etc.
، ۱۳۹۰
Name of Manufacturer
، افشاری
NOTES PERTAINING TO PUBLICATION, DISTRIBUTION, ETC.
Text of Note
چاپی
CONTENTS NOTE
Text of Note
In recent decades some factors such as calculation fouls, mistake in construction and implementation, limitations in current codes and regulations and changes in structural and operating loads have resulted in upward tendency to strengthen of structural elements in reinforced concrete structures. Therefore FRP composites have been considered due to specifications such as high tensile strength, low weight, fast and ease of manufacturing and perform and low costs. Bending behavior and capacity of reinforced concrete beams strengthened by CFRP is studied in this thesis. According to many studies done by different researchers, most of strengthened beams failed due to sudden detachment of FRP (debonding phenomen) or anchorage failure. Therefore the main problems is to solve or postpone these kinds of failures up to enough ductility in resulting complete performance and utilization of ultimate capacity of FRP. In this study, two new anchorage techniques were used that have not been used yet. The first technique includes welding transverse bar NSM to the longitudinal tensile reinforcement and covering the end of FRP around it. This work is done for preventing from pulling out the anchorage system. At the second method, two plates were used near the supports of the beam connected to the longitudinal tensile reinforcement, by welded angles. The FRP sheets are connected two end plates and fixed by another plate located over them. In this study ten reinforced concrete beam specimens were provided with dimensions of 150 mm width, 200 mm height and 2000 mm length in two different series. The beam sections were used with the same ratio in two series of specimens and then because of different concrete mixes (fc=21 MPa and fc=35 MPa) used in each series of beams the ductility of the specimens were different. Test results in each series were compared with these of normal reinforcement concrete beams as a controlling criteria. The width, thickness and number of layers of CFRP sheets in all specimens were the same and only some characters such as anchorage type and the length of layers according ACI code and rehabilitation code of Iran,were different considering in cut off point layers. According to test results there is a considerable increasing of ultimate bending capacity of strengthened beams using by both of the purposed anchorages. Additionally the plate anchorage has better performance and more applicability in comparison to NSM or the another used anchorage methods in different referencies. resistance rising 95.43. by the plate anchorage are obtained in contrast to 66.73. with NSM anchorage for 21MPa specimens and 72.90. in contrast to 46.84. for 35MPa specimens, respectively. Moreover, the results of inhibiting the end of both longitudinal sheets at plates are better than the state that the end of one longitudinal sheet inhibited at plates. resistance rising for 21MPa specimens are reported 95.43. in contrast to 88.02. and 72.90. in contrast to 30.83
DISSERTATION (THESIS) NOTE
Dissertation or thesis details and type of degree
کارشناسی ارشد
Discipline of degree
مهندسی عمران-سازه
Date of degree
۱۳۹۰/۰۸/۱۱
Body granting the degree
تبریز
SUMMARY OR ABSTRACT
Text of Note
یکی از رویکردهای اصلی در چند دهه اخیر تقویت المان‌صهای سازه‌صای) مخصوصا سازه‌صهای بتن آرمه (به علت‌صهای مختلفی همچون خطاهای محاسباتی، اشتباه در ساخت و اجراء، ضعف آیین نامه‌صهای قدیمی و یا تغییر کاربری سازه و بارهای بهره‌صبرداری وارده می‌صباشد که از این میان کامپوزیت‌صهای مسلح به الیاف (FRP) ها با ویژگیهایی چون مقاومت کششی بالا، وزن کم، سرعت و سهولت در ساخت و اجراء و در نتیجه هزینه‌صهای پایین بسیار مورد توجه قرار گرفته است .در این پایان‌ص نامه نیز رفتار و ظرفیت خمشی تیرهای بتن آرمه تقویت شده با صفحات پلیمری مسلح به الیاف کربنی (CFRP) مورد مطالعه قرار می‌صگیرد .مطالعات و پژوهش‌صهای صورت گرفته در این زمینه مؤید این واقعیت است که اکثر تیرهای تقویت شده با این مصالح با جداشدگی ناگهانی FRP از زیر لایه بتنی) پدیده debonding) و یا گسیختگی‌صهای مهاری دچار شکست شده‌صاند .بنابراین در این تحقیق توجه اصلی به حل این معضلات و یا حدالامکان به تأخیر افتادن آنها می‌صباشد تا شکل پذیری کافی در نتیجه عملکرد کامل کامپوزیت و بهره‌صگیری از ظرفیت نهایی FRP میسر گردد .در همین راستا از دو تکنیک مهاری جدید که تا کنون مورد استفاده قرار نگرفته-اند، استفاده می‌صشود
Text of Note
In recent decades some factors such as calculation fouls, mistake in construction and implementation, limitations in current codes and regulations and changes in structural and operating loads have resulted in upward tendency to strengthen of structural elements in reinforced concrete structures. Therefore FRP composites have been considered due to specifications such as high tensile strength, low weight, fast and ease of manufacturing and perform and low costs. Bending behavior and capacity of reinforced concrete beams strengthened by CFRP is studied in this thesis. According to many studies done by different researchers, most of strengthened beams failed due to sudden detachment of FRP (debonding phenomen) or anchorage failure. Therefore the main problems is to solve or postpone these kinds of failures up to enough ductility in resulting complete performance and utilization of ultimate capacity of FRP. In this study, two new anchorage techniques were used that have not been used yet. The first technique includes welding transverse bar NSM to the longitudinal tensile reinforcement and covering the end of FRP around it. This work is done for preventing from pulling out the anchorage system. At the second method, two plates were used near the supports of the beam connected to the longitudinal tensile reinforcement, by welded angles. The FRP sheets are connected two end plates and fixed by another plate located over them. In this study ten reinforced concrete beam specimens were provided with dimensions of 150 mm width, 200 mm height and 2000 mm length in two different series. The beam sections were used with the same ratio in two series of specimens and then because of different concrete mixes (fc=21 MPa and fc=35 MPa) used in each series of beams the ductility of the specimens were different. Test results in each series were compared with these of normal reinforcement concrete beams as a controlling criteria. The width, thickness and number of layers of CFRP sheets in all specimens were the same and only some characters such as anchorage type and the length of layers according ACI code and rehabilitation code of Iran,were different considering in cut off point layers. According to test results there is a considerable increasing of ultimate bending capacity of strengthened beams using by both of the purposed anchorages. Additionally the plate anchorage has better performance and more applicability in comparison to NSM or the another used anchorage methods in different referencies. resistance rising 95.43 by the plate anchorage are obtained in contrast to 66.73 with NSM anchorage for 21MPa specimens and 72.90 in contrast to 46.84 for 35MPa specimens, respectively. Moreover, the results of inhibiting the end of both longitudinal sheets at plates are better than the state that the end of one longitudinal sheet inhibited at plates. resistance rising for 21MPa specimens are reported 95.43 in contrast to 88.02 and 72.90 in contrast to 30.83 for 35MPa specimens, respectively. Comparing results of these two series in this research indicates that plate anchorage performance is better than the another ones for the same conditions
PERSONAL NAME - PRIMARY RESPONSIBILITY
رنجبراقدم، اورنگ
PERSONAL NAME - SECONDARY RESPONSIBILITY
اسماعیلی، جمشید، استاد راهنما
حدیدی، علی، استاد مشاور
ELECTRONIC LOCATION AND ACCESS
Public note
سیاه و سفید
نمایه‌سازی قبلی
