Retrofitting of RC Beams with Externally Bonded SIMCON Laminates: A Prospective Retrofit System

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. A total of four reinforced concrete beams were cast and tested in the laboratory over an effective span of 3000 mm. Three beams were strengthened with bonded SIMCON laminate at the bottom under virgin condition and tested until failure; the remaining one beam was used as control specimen. All of the beams' static responses were assessed in terms of strength, stiffness, ductility ratio, energy absorption capacity factor, laminate-concrete compositeness, and associated failure modes. FEA software ANSYS was used to forecast the theoretical moment-curvature relationship for the test specimen as well as the load-displacement response of the strengthened beams and control beam. Based on the experimental results, it can be observed that significant increase in strength can be realised at all the load levels by externally bonding SIMCON laminates. This increase may be attributed to the increase in tensile cracking strength of concrete due to confinement. Further it is to be noted that increase in load carrying capacity is possible only when other modes of failure do not interfere. 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.