FraMCoS 6 2007 Catania, Italy

Assessment of the residual Fatigue Strength in RC Beams

In conventional analysis and design procedures of reinforced concrete structures, the ability of concrete to resist tension is neglected. Under cyclic loading, the tension-softening behavior of concrete influ- encesitsresidualstrengthandsubsequentcrackpropagation. Thestabilityandtheresidualstrengthofacracked reinforced concrete member under fatigue loading, depends on a number…

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Year 2007
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Abstract

In conventional analysis and design procedures of reinforced concrete structures, the ability of concrete to resist tension is neglected. Under cyclic loading, the tension-softening behavior of concrete influ- encesitsresidualstrengthandsubsequentcrackpropagation. Thestabilityandtheresidualstrengthofacracked reinforced concrete member under fatigue loading, depends on a number of factors such as, reinforcement ra- tio, specimen size, grade of concrete, and the fracture properties, and also on the tension-softening behavior of concrete. In the present work, a method is proposed to assess the residual strength of a reinforced concrete membersubjectedtocyclic loading. The crack extension resistance based approach is used for determining the condition for unstable crack propagation. Three different idealization of tension softening models are consid- ered to study the effect of post-peak response of concrete. The effect of reinforcement is modeled as a closing force counteracting the effect of crack opening produced by the external moment. The effect of reinforcement percentage and specimen size on the failure of reinforced beams is studied. Finally, the residual strength of the beamsare computedby includingthe softening behavior of concrete.