Abstract
Reversed cyclic bending tests were performed on reinforced concrete beams reinforced with large-sized deformed bars. These bars designated as D 64, having nominal diameter of 64 mm and screw-type rolled deformation, have been developed to apply large-scaled structures such as nuclear power plants and other containment structures. It was shown from the comparison between specimens reinforced with D64 and half-scale specimens reinforced with D32 that there is no scale effect in crack pattern and flexural deformation behavior in pre- and post-yielding stages. This means that the maximum surface crack width at a given steel stress increased proportionally with the increase of bar diameter because bar spacing and concrete cover were determined in proportion to bar diameter in these beams. It was demonstrated that the additional arrangement of welded deformed bar mat near the bottom concrete surface at 10 mm concrete cover decreased drastically the maximum surface crack width.
