Suppression of softening in the load-deflection diagram of concrete-filled tubular columns and spiral columns is proposed to serve as a design criterion helping to avoid the size effect and explosive brittle character of collapse. To this end, the recently developed ‘‘tube-squash’’ tests, in which a short concrete-filled steel tube is squashed to about a half of its original length and allowed ...

The paper reviews experimental evidence on the size effect caused by energy release due to fracture growth during brittle failures of concrete structures. The experimental evidence has by now become quite extensive. The size effect is verified for diagonal shear failure and torsional failure of longitudinally reinforced beams without stirrups, punching shear failure of slabs, pull-out failures ...

Abstract.The paper focuses on the modelling of the quasi-brittle failure of materials with a heterogeneous microstructure. Failure induced anisotropy is incorporated in terms of the microplane theory. This theory is based on scalar damage laws formulated on several individual material planes. Anisotropy of the overall constitutive law is introduced in a natural fashion by transforming the scala...

In the present paper a fully coupled three-dimensional thermo-hygro-mechanical model for concrete is discussed and used in the numerical studies. The model is formulated in the framework of continuum mechanics based on the principles of irreversible thermodynamics. Distribution of moisture, pore pressure, temperature, stresses and strains are calculated by employing a three-dimensional transien...

Anchorages of non-rectangular configuration, though not covered by current design codes, are often used in practice due to functional or architectural needs. Frequently, such anchor groups placed close a concrete edge and subjected shear loads. The anchorages requires engineering judgement no clear rules given the codes standards. In this work, numerical investigations using nonlinear 3D FE ana...