Repairing of reinforced concrete I-beams failed in shear by externally bonded carbon fiber reinforced polymer (CFRP)‎ sheets

العناوين الأخرى

تصليح الكمرات الخرسانية المسلحة ذات مقطع (I)‎ الفاشلة في القص برقائق مصنعة من المواد البوليمرية المسلحة بألياف الكربون من الخارج

مقدم أطروحة جامعية

Qadir, Kovan Aziz

مشرف أطروحة جامعية

Muhammad, Ahmad Hidayat

أعضاء اللجنة

Jalal, Shawnim Rashid
Mahmud, Abd al-Karim Darwish
Yusuf, Ali Ramadan
Sulayvany, Biyar Jafar

الجامعة

جامعة صلاح الدين

الكلية

كلية الهندسة

القسم الأكاديمي

قسم الهندسة المدنية

دولة الجامعة

العراق

الدرجة العلمية

ماجستير

تاريخ الدرجة العلمية

2011

الملخص الإنجليزي

The use of external fiber-reinforced polymer (FRP) has become a popular technique of retrofitting (strengthening) of concrete structures in recent years.

The use of FRP sheet bonded to rectangular and T-concrete beams has been studied by many Researchers.

The main objectives of this research was to evaluate the shear behavior of reinforced concrete I- beams strengthened with different configurations of CFRP sheet and verify the effectiveness of externally bonded CFRP sheet for shear strengthening applied onto I beams with anchorage and without anchorage.

Also verify the effectiveness of re-cast the sides of the web to transfer the I-section to rectangular section, then externally bonded with CFRP sheet for shear strengthening.

The experimental program consists of casting eleven reinforced concrete I-section beams, the beams were preloaded up to 80% of carry capacity, released, strengthened with CFRP sheets, then loaded up to failure.

The beams were divided in to three main groups (G1, G2 and G3).

First group (G1) consists of four beams, one control beam and three shear strengthened beams with external bonded CFRP sheets, the CFRP configurations were as follow; two sides, U jacketing (three sides) and fully wrap configurations but there was no longitudinal anchorage for this group.

The second group G2) consists of three beams, all beams were strengthened by externally bonded CFRP as first group, but there was a longitudinal anchorage for this group, the anchorages were another sheets of 80mm width of CFRP fixed on the beams where the flanges meet web on the transverse CFRP sheet.

The third group (G3) consists of four beams, one control beam and three shear strengthened beams by external bonded CFRP sheets, the CFRP configurations were like the first group (G1), but before applying CFRP sheets the remaining parts of the web were re-cast with concrete (i.e.

the beam after recasting became rectangular beam) and there was no longitudinal anchorage for this group.

The Results show that there is no increasing in shear capacity of the I-beams for the first group (G1), and this happened due to de-bonding of CFRP sheets at the earlier stage of the loading.

The second group (G2) results show an increase in shear capacity of the I-beams, for instance the ultimate shear capacities of this group 19 %, 16 % and 13 % for two sides, U-jacketing and fully wrap configurations, respectively were more than the control beam (B1-0S) and the third group (G3) results show that the strengthened Ibeams with CFRP sheet after re-cast them was a better way to increase the shear capacity of the I-beams, for instance the shear improvement were 34 %, 34 % and 36 % more than control beam (B1-0S) for two sides, U-jacketing and fully wrap configurations, respectively.

Two equations were proposed to calculate the effective strain of FRP sheets for Ibeams for second and third groups.

Depending on the pervious equations for strain, the shear carry capacity equations of the strengthened beam were found.

The suggested equations show better results than ACI 440.2 R-08, when applied on too limited experimental data available.

التخصصات الرئيسية

الهندسة المدنية

الموضوعات

• الصيانة
• الترميم

عدد الصفحات

151

قائمة المحتويات

• APA
• MLA
• AMA

لغة النص

الإنجليزية

نوع البيانات

رسائل جامعية

رقم السجل

BIM-310668