COMPARISON OF RESULTS OBTAINED FROM ANALYTICAL AND EXPERIMENTAL INVESTIGATIONS OF RC BUILDING COLUMNS USING CFRP

The focus of the research in this paper is Quasi-static tests on RC building columns strengthened with CFRP (Carbon Fiber Reinforced Polymers). To present the possibilities and the benefits of use of these materials, laboratory research for definition of the characteristics and experimental investigations of RC columns strengthened by CFRP by variation of concrete class, reinforcement percentage and different technologies of strengthening, are carried out at the Institute of Earthquake Engineering and Engineering Seismology – IZIIS, Skopje. Some recommendations and outcomes regarding the approach and technology of practical application of these materials, will be given. Selected results from laboratory testing of built-in materials, part of analytical results and part of quasi-static experimental investigations of models designed and constructed by use of CFRP-materials are presented. Based on the analysis of values obtained from nonlinear static and nonlinear time history analyses, it can be concluded that the ductility capacity for displacement of models strengthened with CFRP is greater than 60%, while its strength capacity is greater than 7.7% when compared to the values obtained for the models without CFRP. It can generally be concluded that CFRP systems are a very practical tool for strengthening and retrofitting RC building structures, as they can extensively improve flexural strengthening, shear strengthening, column confinement and ductility, thus, contributing towards better seismic resilience of the structures. Keywords: RC columns; quasi-static tests; innovative materials; CFRP; strength; ductility.