MECHANICAL PROPERTIES AND ANALITICAL CONSIDERATIONS OF HIGH STRENGTH CONCRETE UNDER TRIAXIAL COMPRESSIVE STRESS CONDITIONS

摘要

Recently, in the construction of concretestructures such as a depth underground one and a high risebuilding, etc, it is expected to be used more often a highstrength concrete for the purpose of creasing of a deadweight and an economic improvement. Moreover, in orderto analyze the concrete structure subjected to threedimensional forces, it is necessary to develop a nonlinearanalytical method considering mechanical characteristicunder triaxial compressive stresses.In this study, the pure triaxial compression test forthe high strength concrete was performed, and the me-chanical characteristic was clarified. It was shown thatan ultimate strength and ultimate strain for the highstrength concrete under triaxial compressive stressesremarkably increased more than under uniaxial com-pressive stress. The ultimate strength envelopes forthe high strength concrete could be expressed byprevious descriptions for normal strength concrete.Further, mathematical descriptions of ultimate strainsurface were derived from experimental results.The model of a stress-strain relationship wasproposed by using a hypo elastic orthotropic approachthat based on an equivalent uniaxial strain theory.This model was able to predict the stress-strainrelationship alone any stress path. It was cleared thatthe analytical stress-strain curves for the high strengthconcrete in Rendulic and deviatoric stress planeagreed well with experimental results including in softening region.