ABSTRACT
The previous experimental investigations on confined concrete provided valuable data to modelers, especially on the shape of the strength envelope (PNSPeak Nominal Stress surface), cyclic behaviour, damage patterns and stress-strain behaviour in the post-peak region. However due to a combination of various restrains, related to limited loading capacity, inadequate boundary conditions and above all relatively crude control systems, researchers were prevented from undertaking more sophisticated experiments needed for (i) establishing direct links between damage development and the globally observed stressstrain behaviour, (ii) separating the time dependent (viscous) from plastic strains, (iii) detecting the shapes of loading (yield) surfaces and (iv) investigating the influence of temperature changes on the behaviour of concrete under multiaxial compression.
