Serhat Demir

The behaviour of high-strength reinforced concrete columns under low eccentric loading

In this study, the change of the behaviour of high-strength reinforced concrete (HSRC) columns under axial and eccentric load based on the ratios of transversal and longitudinal reinforcements was investigated. To do this, 2100 mm height and 200 mm × 300 mm cross-sectional sizes reinforced concrete columns which have different transversal and longitudinal reinforcement ratios were produced with high-strength concrete. On these produced columns, two different eccentricity (e = 25 mm and e = 50 mm) and axial (e = 0) loadings were done. The experimental and theoretical moment–curvature (M–K) relations were determined and compared with each other. Test results showed that in the HSRC columns, the ratio of longitudinal reinforcement did not changed the fracture type which was brittle, but when the ratio of transversal reinforcement increased, the type of fracture was changed. The M–K relation obtained from the experiments and the M–K relation calculated theoretically were in harmony. This showed that the material model which was used to determine theoretical M–K relation was suitable for HSRC.

THE EFFECT OF FRACTURE AND CRACK GROWTH OF STEEL AND POLYPROPYLENE FIBERS IN THE ORDINARY AND HIGH STRENGTH CONCRETE

Today, high performance concrete can be produced as easily as normal strength concrete. Concretes are expected to have ductile behavior and have compressive strength, as well. In the recent years, in order to have ductile behavior, researchers have started to strengthen concrete using fibers and have done lots of researches. In this study, normal and high strength concrete with steel and polypropylene fiber are produced, the compressive strength and the tensile strength in split of these concrete is investigated and the fracture energy and crack distribution of notching samples are examined.