PARAMETRIC STUDY OF RC GIRDERS STRENGTHENED IN FLEXURE USING PRESTRESSED NSM CFRP STRIPS

Fiber Reinforced Polymer (FRP) materials have been used for strengthening and retrofitting concrete bridges all around the world. This paper presents results of a parametric study using Finite Element Modelling (FEM) performed on 5.0m long Reinforced Concrete (RC) girders strengthened in flexure with prestressed Near-Surface Mounted (NSM) Carbon FRP Strips. The developed FE model was first validated with experimental test results. The validated FE model is expanded to investigate the effect of three parameters including: the prestressing level in the NSM CFRP strips, the tensile steel reinforcement ratio, and the concrete compressive strength. The influence of these parameters on the negative camber due to prestressing; cracking, yielding, and ultimate loads and deflections; mode of failure; and ductility index are examined. In addition, the optimum prestressing level for each internal steel ratio to preserve the amount of energy absorption of the strengthened beam identical to the un-strengthened control beam is appraised.

Keywords:

Finite element modelling , Carbon fiber reinforced polymer , Prestressed , Near Surface Mounted