EXPERIMENTAL ANALYSIS OF FATIGUE BEHAVIOR OF STRENGTHENED REINFORCED CONCRETE SHORT CORBEL BY EXTERNALLY BONDED CARBON FIBRES FABRICS

References: 14th International Multidisciplinary Scientific GeoConference SGEM 2014, www.sgem.org, SGEM2014 Conference Proceedings, ISBN 978-619-7105-21-6 / ISSN 1314-2704, June 19-25, 2014, Book 6, Vol. 2, 153-160 pp

ABSTRACT
This paper presents experimental study of strengthening reinforced concrete corbel by gluing carbon fibres fabrics. Indeed, in buildings and in civil engineering reinforced concrete corbels often are used. A preliminary study to determine the number of layers necessary optimal and effective strengthening. Then, we compare usefully unstrengthen and strengthened reinforced concrete short corbels with monotonic loading to failure and cyclic loading up to one million cycles. Cracking of corbels are described and different failure modes observed. The effect of some parameters on behavior of the strengthening structure is examined. As such as, influence of the type of strengthened reinforced concrete corbels directly on either sides or wrapping by externally bonded the carbon fiber sheet. The influence of the orientation of the carbon fibres fabrics is also examined. The influence of the extensometer technique based on electrical strain gauge strain is used to study the local behavior of the structure. This technique allows to measure strain of steel, carbon fabrics and concrete. The ultimate load and displacement of the specimen are compared to the reference structure of static tests monotonous load applied. The cracking and the mode of failure under static loading are presented. The results show an increase of more than 82% of the bearing capacity of corbels and improving their rigidity of the third. Cyclic loading modifies the stress distribution within the corbels therefore also the cracks where some cracks appear in the stake but not observed in the case of monotonic loading. Cracking corbels are different depending on the case load (monotonic or cyclic).

Keywords: strengthening, short corbel, fatigue behavior, reinforced concrete composite materials.