Administrative Information

المعلومات الادارية

عنوان المشروع- Project Title

Effect of FRP confinement on the bond strength of steel bars under static and seismic loading: Application for exterior beam-column connection and gravity load-designed columns

تحسين إجهاد التماسك للتسليح الطولي باستخدام التطويق الخارجي بالألياف البوليمرية تحت الأحمال الاستاتيكية والهزات الأرضية

الباحث الرئيسي Principal Investigator -

الاسم Name	المؤسسة Institution	الوظيفية Post	العنوان Address	العنوان الالكتروني e-mail	رقم الهاتف Telephone
M. Harajli	AUB	Professor		mharajli@aub.edu.lb	Ext. 3527

الباحثون المشاركون Co-Workers -

الاسم Name	المؤسسة Institution	العنوان الالكتروني e-mail
B. Hamad	AUB	Bilal@aub.edu.lb

المدة التعاقدية للمشروع Duration -:

2 years

Scientific Information

المعلومات العلميّة

الهدف- Objectives

To evaluate the effect of FRP confinement on the response of gravity load-designed columns and under seimic loading for the purpose of seimic retrofit of the columns.

ألانجازات المحققة Achievements -

An experimental program was carried out and a design expression is generated for evaluating the minimum thickness of FRP jacket required for bond strengthening of bond-critical regions in reinforced concrete columns.

آفاق البحث Perspectives -

The research is importabnt for seismic repair and strengthening of concrete columns where the structural failure under earthquake load is likely to occur due to inferior bond resistance of the steel reinforcement.

المنشورات والمساهمات في المؤتمرات- Publications & Communications

Harajli, M. H., and Daghir, F., "Influence of Bond Strengthening of Spliced Steel Bars Using FRP Jackets on the Seismic Response of Rectangular RC Columns - Experimental Evaluation," Accepted for presentation and publication in the Proceedings of the 8^th International Symposium on Fiber Reinforced Polymer Reinforcement for Concrete Structures, Athens Greece, July 16-18, 2007.

Harajli, M. H., "Seismic Behavior of RC Columns with Bond-Critical Regions: Criteria for Bond Strengthening using External FRP Jackets," Accepted for publication in the Journal of Composites for Construction, ASCE.

Harajli M. H., and Daghir, F., "Seismic Strengthening of Bond-Critical Regions in Rectangular RC Columns Using FRP Wraps," Submitted for peer review and possible publication in the ASCE Structural Journal.

Daghir, F., and Harajli, M. H., "Seismic Strengthening of Bond - Critical Regions in Rectangular RC Columns Usinfg External FRP Jackets," Thesis presented by the first author in partial fulfillment of the requirements for the MS degree in Civil Engineering, Amertican University of Beirut, 2006, 87 pp.

موجز عن نتائج البحث Abstract -

The use of external fiber reinforced polymer (FRP) wraps for bond strengthening of

spliced reinforcement in rectangular reinforced concrete (RC) columns and the consequent effect on the seismic response of the columns is experimentally investigated. Full scale unconfined and FRP confined column specimens with lap-spliced reinforcement at the base were tested. Also, companion columns with continuous reinforcement and with internal steel confinement to satisfy the ACI Building code requirements for regions of high seismic hazard (earthquake resistant columns) were tested for comparison. It was found that confining the spliced zone with FRP wraps increased the bond strength of the spliced bars, reduced the bond deterioration and pinching under cyclic loading, and increased the lateral load resistance and ductility of the columns. The corresponding improvements approached those of the earthquake resistant columns. The lateral strain developed in the FRP increased with decreasing ratio of concrete cover to splice diameter and with increasing area of FRP wraps. Based on the results of this study a general design expression is generated to estimate the thickness of the FRP jacket required fort seismic retrofit of bond critical regions in RC members.