Full-scale experimental and theoretical investigation into the behavior of reinforced concrete beams flexurally strengthened with CFRP strips by near-surface mounted technique

العناوين الأخرى

التقصي العملي و النظري للسلوك الإنشائي للعتبات الخرسانية المسلحة المقواة أنحنائيا بصفائح البوليمر المسلح بالألياف الكاربونية بواسطة طريقة التثبيت السطحي

مقدم أطروحة جامعية

Dhiyab, Hasanayn Muhammad

مشرف أطروحة جامعية

Ali, Anis Abd al-Khidr Muhammad

الجامعة

جامعة البصرة

الكلية

كلية الهندسة

القسم الأكاديمي

قسم الهندسة المدنية

دولة الجامعة

العراق

الدرجة العلمية

دكتوراه

تاريخ الدرجة العلمية

2012

الملخص الإنجليزي

This research presents full-scale experimental and theoretical investigation into the behavior of reinforced concrete beams flexurally strengthened with carbon fiber reinforced polymer (CFRP) strips by Near Surface Mounted (NSM) technique.

The experimental work includes testing of Twenty-one reinforced concrete beam specimens with dimensions (200 mm x 300 mm x 3200 mm), Thirteen of these beams were strengthened by NSM technique, one beam was strengthened with external CFRP strip, one beam was repaired with carbon fiber reinforced polymer (CFRP) strips and six specimens were tested without strengthening acts as reference beam (control) for comparing the performance of CFRP strengthened or repaired beams.

The experimental variables considered in the test program include the location, dimensions and number of CFRP strips, compressive strength of concrete and the amount of the tensile reinforcement.

All the reinforced concrete beam specimens were designed of the same dimensions and reinforced identically to fail in flexure.

All beams had been tested in simply supported conditions subjected to four point load.

The experimental results show that the ultimate loads are increased by about (38-101 %) for the beams strengthened with CFRP strips by NSM technique with respect to the unstrengthened reinforced concrete beam (control beam).

Three-dimensional nonlinear finite element analysis had been carried out to conduct the numerical investigation of the general behavior of strengthened beams.

ANSYS (Version 11.0, copyright 2007) computer program was used in this work.

Eight-node brick elements (SOLID65) had been selected to represent the concrete and three dimensional shell elements (SHELL 63) had been used to represent the CFRP strips in the finite element analysis model.

Perfect bond between the concrete surface and the bonded CFRP strips is assumed.

The comparison between the numerical and the experimental results asserted good validity of the numerical analysis and the methodology developed in this study where the maximum difference ratio in ultimate load was less than 10 % for all the tested and analyzed beams.

Parametric study has been carried out to investigate the effect of some important material parameters.

These parameters include the effect of flexural strengthening method, thickness, width and length of CFRP, height of the beam, longitudinal reinforcement, shear span length, compressive strength and crack pattern at different load.

The parametric study with respect to the thickness of the CFRP plate shows that the thickness has a significant effect on the load–deflection behavior of CFRP-reinforced concrete beam.

A 50 %, 100 %, 150 % and 200 % increase in the thickness of CFRP plate caused an increase of 7.69 %, 10.26 %, 14.1 % and 17.95 % in the ultimate load capacity of the CFRP-reinforced concrete beam respectively.

The width of the CFRP plate affects the overall load-deflection behavior of the CFRP-concrete beams.

A 50% and 100% an increase in the CFRP plate width caused an increase of 15.38 % and 23 % in the ultimate load capacity of the CFRP-reinforced concrete beam respectively.

A 78 % and 178 % an increase the longitudinal reinforcement of the CFRP-concrete beam caused an increase of 20.51% and 46.15 % in the ultimate load capacity of the CFRP-reinforced concrete beam respectively.

Finally 31.58 %, 57.89 % and 84.21 % an increase in the compressive strength of the CFRP-concrete beam caused an increase of 16.67 %, 23 % and 35.9 % in the ultimate load capacity of the CFRP-reinforced concrete beam respectively.

التخصصات الرئيسية

الهندسة المدنية

الموضوعات

• الخرسانة المسلحة

عدد الصفحات

199

قائمة المحتويات

• APA
• MLA
• AMA

لغة النص

الإنجليزية

نوع البيانات

رسائل جامعية

رقم السجل

BIM-317318