Strain-Softening of Concrete under Multiaxial Loading Conditions

摘要

The main purpose of the study is to obtain further experimental stress-strain data for concrete under multiaxial load histories, including strain softening (i.e. the failure conditions), and to try to understand the governing phenomena. The experimental results are discussed critically in relation to the experimental technique that was adopted. Major emphasis is laid on stress-strain behavior under triaxial conditions including the softening branch, but also on observed rupture modes in relation to the stress-strain programs. The use of damage models, relating internal structural changes and macroscopic phenomena is discussed. Also some 'smearing methods' are examined. Important in the discussion is to decide if a continuum description of triaxial concrete behavior is acceptable, or whether a discrete model is required. Some additional experimental results following so-called 'rotation-paths' are shown. Also some very first small angle rotations using the preload/saw method are indicated.