Authors

Abstract

This investigation presents an experimental study of strength and behaviour of various types of reinforcement details in concrete corner subjected to bending moment tended to open the angle. Ten specimens with various arrangements of reinforcement in the corner region are tested to study the effect of reinforcement detail, corner strength, cracks type, cracking moment, cracks pattern, corner deflection and corner efficiency. The specimens are designed to represent an actual prototype of a portal frame corner. The compressive strength of concrete in the test varies from (37.1) to (43.6) MPa, and steel tension ratio in legs is constant at ρ = 0.0081 in all test specimens. The nominal dimensions of the tested corners are (1077.8 mm) in overall length, (600 mm) in height and (150mm) in thickness, the nominal width, and the effective depth for all corner's leg section is held constant at (150 mm) and (129 mm) respectively. All corners are supported to be hinged in one leg by two hooks and rolled in other leg, also all corners are loaded by steel frame where, it produces moment tends to open the angle. Concrete strains at three different loading stages are recorded for each tested corner; also load deflection curves were plotted. Throughout the test operation crack patterns were drawn and the mode of failure of the tested corners is identified, which is divided into two types (flexural and bearing) failure. It was found that reinforcement detailing in corners subjected to moment tends to open the corner has important effect on the strength and the mode of failure of the corner. Depending on the results of the current experimental work some details are recommended to be used in the field work.

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