نوع مقاله : پژوهشی
نویسندگان
1 دانشکده ی مهندسی عمران-دانشگاه صنعتی اصفهان
2 دانشکده ی مهندسی عمران، دانشگاه صنعتی اصفهان
چکیده
کلیدواژهها
موضوعات
عنوان مقاله [English]
نویسندگان [English]
The application of FRP composites is one of the most prevalent methods for
retrofitting concrete structures. Strengthening of columns as a major member of
structures undergoing concentric or eccentric loads is of considerable
importance. The column under eccentric loading experiences lateral deflection
at any particular column height, which is defined as an eccentricity for the
axial load at both ends of the column. The lateral deflection would lead to the
secondary moment, whose combination with the primary moment will produce more significant effects. Although concrete columns are mostly under eccentric
loading in practical use and are vulnerable to instability caused by the
slenderness effect, limited experimental studies have been conducted on the
behavior of slender concrete columns strengthened with FRP composites in
comparison with strengthened short columns. Previous studies state that the
strength of columns increases with retrofitting with FRP; however, the strengthening effect of FRP on the column under axial-bending (P-M) loading
would be reduced with an increase in slenderness. In other words, the capacity
of FRP is not achieved completely since the column is vulnerable to instability
and buckling. As a result of that, the slenderness effect may prevent the
column to achieve its maximum load-carrying capacity. In this study, six
concrete specimens in the height of 900 mm under eccentric loading with 60 mm
eccentricity were tested. Half of the specimens were with a circular cross-section and half with a square cross-section. All the specimens are retrofitted with FRP composites in the longitudinal direction using externally bonded reinforcement (EBR) and externally bonded reinforcement on grooves (EBROG) method. Results show that for the columns strengthened via the EBROG method, the load-carrying capacity is more than that of reference and EBR columns. Furthermore, the EBROG method decreases secondary effects and increases ductility in slender columns compared with reference and EBR columns.
کلیدواژهها [English]
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