Vol.12, No2, 2012, pp.93–98
UDC 620.1:691.32

The aim of this work is to characterize the toughness of frost damaged normal vibrated concrete. From force-deflection and force-crack opening curves, obtained by means of three-point bending tests performed on notched specimens, toughness parameters are evaluated as a function of freezing-thawing cycle numbers. The results show that the stress intensity factor, K_IC, and the flexural tensile strength, σ_ft, decrease while the critical crack mouth opening displacement CMOD_c, increases. The variation of these parameters is correlated to the degree of concrete damage characterized by the relative variation of flexural strength and an analytical model of crack propagation is used for the interpretation of results.

Keywords: frost action, fracture parameters, crack propagation