Fatigue Behavior of Concrete Beams Prestressed with Partially Bonded CFRP Bars Subjected to Cyclic Loads

Abstract

The lack of ductility is the greatest concern in the applications of carbon fiber reinforced polymer (CFRP) materials, when used as pre-stressing reinforcements. To improve the ductility, a partially bonded FRP system which is intentionally unbonded in the middle part of the beam and bonded in both end parts of the beam has been developed and applied to prestressed concrete beams. While, many researchers investigated the instantaneous performance of partially bonded CFRP prestressed concrete beams, this study intended to evaluate the fatigue performance, the static load-carrying capacity after fatigue loading and ductility. Based on the fatigue loading tests followed by static loading tests, over-reinforced and web-confined partially bonded CFRP prestressed concrete beams exhibited satisfactory fatigue performance without cracks and stiffness degradation during fatigue loading. In addition, no degradation of load-carrying capacity was observed in static loading tests after the fatigue tests. The ductility index of concrete beams, prestressed with partially bonded CFRP bars, is combined with over-reinforcements and web-confinements, similar to that of beams prestressed with steel bars.

Effect of Bond Condition on Cyclic Behavior of Post- Tensioned Concrete Beams with Carbon Fiber-Reinforced Polymer Tendons

“…The results indicated that an increase in the unbonded length led to a decrease in ultimate capacity while promoting improved deformability. Jeong et al (2019) evaluated the fatigue performance of post-tensioned concrete beams with partially bonded CFRP tendons. It was found that the partially bonded CFRP prestressed beams exhibited satisfactory fatigue performance, with no signs of cracks or stiffness degradation during fatigue loading.…”

“…Nevertheless, the anchorage of fully unbonded FRP prestressed concrete members remains a critical challenge. Despite efforts made over the past two decades, efficient and competitive prestressing anchor systems for FRP tendons are still limited (Jeong et al 2019).…”

Study on Bond-Slip Behavior between Seawater Sea-Sand Concrete and Carbon Fiber-Reinforced Polymer (CFRP) Bars with Different Surface Shapes

“…They showed that the bond strength of ribbed GFRP bars was greater and the slip value was lower when the protective layer thickness was small, because the failure mode changed to splitting failure rather than pull-out failure. Jeong et al [38] investigated the fatigue behavior of partially bonded CFRP bar-reinforced concrete beams subjected to cyclic load. Zhao et al [39] carried out an experimental study to evaluate the bond behavior between CFRP bars, GFRP bars, steel strands and concrete, and pointed out the bond strength retention rate of GFRP bars was the highest, while that of steel strand was the lowest.…”

Plastik Şekil Değişimine Uğramış Otomobil Rotunun Yorulma Davranışının Deneysel ve Sayısal Analizi

“…Literatürde, plastik deformasyona maruz kalmış rotların yorulma davranışını inceleyen herhangi bir araştırmaya bilgi dâhilinde rastlanmamıştır. Ancak kompozit yapılar [8], beton köprü [9] ve kirişler [10] Basquin uzun yıllar önce gerilme ile ömür arasındaki ilişkiyi logaritmik ölçekte doğrusal olarak aşağıdaki gibi ifade etmiştir [13].…”