A mathematical description of the strength properties of concrete under generalized stress

Abstract

Synopsis A mathematical description of the ultimate strength envelope of concrete under axisymmetric stress states has been derived by analysing experimental data obtained in previous investigations of the Concrete Materials Research Group at Imperial College. The derived equations, when combined with an proposed elsewhere for the description of the effect of the intermediate stress σ2 upon the ultimate strength level, define a surface in stress space which provides a simple mathematical representation of the ultimate strength of concrete under generalized short-term loading conditions. The resulting ultimate strength surface conforms with generally accepted shape requirements and has been found to provide a close fit for most biaxial and triaxial strength data published to date.

A density-dependent failure criterion for concrete

“…The criterion was derived by curve-fitting previously existing mathematical expressions for NWC [31] to axisymmetric strength data for concretes of varying density [26].…”

“…The proposed density-dependent failure criterion in this work [30], is a modification of the criterion proposed by Kotsovos [31]. By decomposing the response of biaxially and triaxially loaded test specimens into octahedral stresses and strains, simple expressions for secant and tangent bulk and shear moduli were developed which are only dependent on stress level and compressive strength.…”

A quantification of the modelling uncertainty of non-linear finite element analyses of large concrete structures

“…Alternatively, fully triaxial material models where all material effects are treated, could be used. One such material model has been developed by Kotsovos and co-workers since the 1970s and is still subject to improvements Cotsovos and Pavlovic, 2006;González Vidosa, Kotsovos, and Pavlovic, 1991a,b;Kotsovos, 1979aKotsovos, , 1980Kotsovos, Pavlovic, and Cotsovos, 2008;Lykidis and Spiliopoulos, 2008;Markou and Papadrakakis, 2013;. Recently, the model was also adapted to light-weight aggregate concrete (Øverli, 2016).…”

3D analysis of solid reinforced concrete beams subjected to combined load of bending, torsion and shear

“…The program was developed by ElNuonu [4] using Kotsovs' concrete model. This model was based on experimental data obtained at Imperial College London from tests on the behaviour of concrete under complex stress states (Kotsovos and Newman [5] and Kotsovos [6]). The testing techniques used to obtain this data were validated by comparing them with those obtained in an international co-operative programme of research into the effect of different test methods on the behaviour of concrete.…”