Flexural behaviour of RC beams strengthened with externally bonded SIMCON laminates

Abstract

This paper presents the results of experimental and analytical studies concerning the flexural strengthening of RC beams using externally bonded Slurry Infiltrated Mat CONcrete (SIMCON) laminates. Preliminary study of SIMCON laminates was carried out for optimizing the volume fraction (Vf) and aspect ratio (l/d) of fiber mat. A total of 45 nos. of laminates of size 125 × 25 × 500 mm with different volume fraction (Vf = 4.0 percent, 4.5 percent, 5.0 percent, 5.5 percent and 6.0 percent) and different aspect ratio (l/d = 300, 400, and cocktail of 300 and 400) were cast and tested in the laboratory. A total of five reinforced concrete beams were cast and tested in the laboratory over an effective span of 3000 mm. Three beams were strengthened with bonded SIMCON laminates of size 125 × 25 × 2950 mm and volume fraction (Vf) 5.5 percent with three different aspect ratios viz: 300, 400, and 300 and 400 cocktail fiber at the bottom under virgin condition until failure; the remaining two beams were used as control specimens. Static responses of all the beams were evaluated in terms of strength, stiffness, ductility ratio, energy absorption capacity factor, compositeness between laminate and concrete, and the associated failure modes. The theoretical moment-curvature relationship for the test specimen and the load-displacement response of the strengthened beams and control beams were predicted by using FEA software ANSYS. Comparison was made between the numerical (ANSYS) with the experimental and theoretical results. The results show that the strengthened beams exhibit increased flexural strength, enhanced flexural stiffness, and composite action until failure.