Photogrammetrically measured deformations of frp wrapped low strength concrete

Abstract

In this study, 8 specimens with square cross-section were tested under compression. The specimen dimensions were 250x250~500 mm. The test program included unconfined specimens as well as specimens jacketed by 1, 3 and 5 plies of carbon fiber reinforced polymer (CFRP) sheets. The unconfined concrete compressive strength was less than 10 MPa for all specimens. Photogrammetric measurements were carried out as well as usual measurement techniques to determine the axial and lateral deformations of the specimens. With the help of photogrammetric techniques, more detailed information was collected about the deformation pattern that led to better understanding of the behavior. The performance of low strength concrete members jacketed by different thicknesses of CFRP sheets are discussed with a special emphasis on the distribution of deformations of the specimens. The effectiveness of the CFRP jackets increased significantly due to deformation characteristics of unconfined concrete with low compression strength. Very significant enhancement was obtained for compressive strength and deformability of CFRP jacketed specimens that resulted with tremendous increase in energy dissipation.