A theoretical model to predict interface slip due to bending

Abstract

Casting a new concrete layer on the tensile or compressive side of a reinforced concrete element is a common technique that is used to increase the flexural capacity of weak reinforced concrete elements. Until now however, a model has not been presented in the literature to evaluate the slip between the two components. Usually, in common practical design, slip is ignored and the strengthened element is assumed monolithic. This may not be a conservative assumption, as any slip would affect the ultimate resistance of the strengthened element. In the present paper, an analytical procedure is presented that predicts the distribution of slip strain, slip and shear stress along a reinforced or unreinforced interface between an initial beam and a new concrete layer. By following this process, the capacity of a strengthened beam is determined by taken slip into account. In addition, a step-by-step design procedure is presented and then applied to an experimental result. Good agreement if found. Further verification of the analytical procedure is performed by comparison with finite element analysis and very good agreement is found.

“Integralization” with new UHPC decks for existing motorway bridges

“…This application can considerably improve the strength and stiffness of existing elements. There are several published experimental and theoretical studies where the behaviour of strengthened beams has been investigated (Trikha et al 1991, Cheong & MacAlevey 2000, Altun 2004, Tsioulou & Dritsos 2011, Tsioulou et al 2013. In case of elements strengthened with additional concrete layers, an important parameter which affects the durability and the performance of the strengthened elements is the concrete shrinkage of the new concrete (Yuan & Marosszeky 1994, Silfwerbrand 1997, Denarie & Silfwerbrand 2004, Abbasnia et al 2005, Beushausen & Alexander 2006, Beushausen & Alexander 2007, Zhou J. et al 2008, Lampropoulos et al 2012.…”

Strengthened Structural Members and Structures: Analytical Assessment

“…The same approach has also been implemented after the necessary modifications for predicting the response of thin reinforced self-compacting three-jacketed beams (Chalioris et al 2014). Moreover, Tsioulou and Dritsos (2011) developed an analytical model for predicting the flexural capacity of beams strengthened by the addition of a concrete layer in the tension or compression zone. The algorithm developed aimed at the evaluation of slip and shear stress distribution along the interface.…”

Experimental investigation results of composite RC beams under cyclic loading

“…Numerous results of experimental studies of shear resistance of flat reinforced and nonreinforced contact joints are presented in the international literature [1,2,3,4]. In most of these experiments, the contact joints were tested with monotonically increasing load until failure.…”