Prestressed FRP Fabrics for Flexural Strengthening of Concrete
The feasibility and advantages of strengthening reinforced concrete (RC) beams by prestressed Fibre-Reinforced-Polymer (FRP) fabrics are examined. Actually this is possible, as a prestressing machine has been designed, suitable to properly seize and prestress the fabric, without risk of ripping it. The device is illustrated and the case of RC beams with inadequate steel reinforcement for bending is treated. A method is proposed and the analytical verifications are shown, that make use of closed-form equations and follow the usual steps commonly taken when strengthening, i.e. to assess the resisting moment capacity of the existing beam, to evaluate the demanded strength increase and to design the amount and prestress level of the strengthening. A design example is also given.
KeywordsReinforce Concrete Reinforce Concrete Beam Steel Area Compression Steel Neutral Axis Depth
The support of Roberto Marnetto and T.I.S. SpA, for the development and the realization of the machine, is appreciated. This work has been funded by the Italian government program “DPC – Consorzio RELUIS”.
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