8302

7700

كارشناسي ارشد

سازه

اصفهان: دانشگاه صنعتي اصفهان، دانشكده عمران

1392

هفده،131ص.: مصور،جدول،نمودار

ص.ع.به فارسي و انگليسي

داود مستوفي نژاد

1/10/92

امير مهرداد محمد حجازي، محمدرضا افتخار

مهندسي عمران

ID7700

به فارسي و انگليسي: قابل رويت در نسخه ديجيتالي

Axial and Bending Behavior of Square Concrete Columns Strengthened with Vertical FRP Strips at Corners and FRP Strips at Sides Alireza Saljoughian Isfahani a saljoughian@cv iut ac ir September 15 2013 Department of Civil Engineering Isfahan University of Technology Isfahan 84156 83111 IranDegree M Sc Language PersianSupervisor Prof D Mostofinejad dmostofi@cc iut ac irAbstractRepairing or strengthening of structural members is required in many cases to prevent damages caused byseismic loading The application of fiber reinforced polymer FRP composites has been successfullypromoted for external strengthening of reinforced concrete RC members such as RC columns Thesejackets are commonly formed in a wet layup process for confinement of columns It has been well establishedin recent studies that rupture strains of FRP measured in tests on such FRP confined RC columns fallsubstantially below those from flat coupon tensile tests Furthermore this problem is more important inrectilinear columns because of premature rupture of FRP at corners due to stress concentration at these parts Up to now numerous studies have been conducted on FRP confined rectangular columns to improve theefficiency of composite in confinement such as using FRP strips at corners In this study a new method was investigated as using CFRP strips at corners and CFRP battens at sides Inthe method FRP composites does not experiment any curvature in confining section and the behavior of FRPis very close to flat coupons in tensile tests For this purpose forty two RC columns with 133x133 mm crosssection for square columns and 110x160 mm cross section for rectangular columns were testedexperimentally under concentric and eccentric 30 60 90 and 120 mm eccentricity loading All of columnspecimens were 500 mm high The experimental results clearly demonstrate that the new method of corner strip batten make more uniformconfinement pressure distribution on section and eliminates the stress concentration at corners so improvesthe performance of FRP in confinement significantly In this case the compressive strength and ductility ofcolumn specimens were respectively increase 11 1 and 42 8 compared to the column confined usingintermittent wrap Based on results obtained from the current study the effectiveness of FRP confinement isreduced under axial flexural loading In this case the compressive strength of column specimens under zero 60 90 and 120 mm eccentricity of loading were respectively increase 42 4 40 4 31 6 and 21 8 compared to the unconfined columns Key Words CFRP composite Rectilinear RC column Confinement Corner strip FRP batten Eccentric loading

داود مستوفي نژاد

امير مهرداد محمد حجازي، محمدرضا افتخار