Stress-Strain Model of Concrete Damaged by Freezing and Thawing Cycles

Abstract

This study investigates the dependence of the mechanical behavior of concrete, such as strength, stiffness, and deformation capacity on the damage caused by freezing and thawing cycles (FTC). A stress-strain model for concrete damaged by freezing and thawing prior to the application of mechanical loading was proposed based on plasticity and fracture of concrete elements. The FTC fracture parameter was introduced to explain the degradation in initial stiffness of concrete resulting from freezing and thawing damage. Based on experimental data, the FTC fracture parameter was empirically formulated as a function of plastic tensile strain caused by freezing and thawing with the assumption that the plastic strain was caused by the combined effects of FTC and mechanical loading damage. The stress-strain relationships obtained by the proposed model were compared with the experimental data.

Mesoscale Simulation of Influence of Frost Damage on Mechanical Properties of Concrete

“…All phenomena observed in this analytical simulation have been confirmed in experiments (Hasan et al 2002a;, which means that the model developed here is well able to simulate the fracture process of frost-damaged concrete. Figure 13 shows the number of mortar and interface boundaries reaching a crack width of 0.03 mm due to compression loading in both undamaged and frost-damaged concrete.…”

“…15, 16 and 17, respectively. In each figure, the analytical results are compared with the previous experimental results (Hasan et al 2002a;Hasan et al 2002b;Hasan et al 2004;Matsumura et al 2003). The good correlations further prove the validity of this meso-scale model for predicting the macro-scale behavior of frost-damaged concrete.…”

“…Compression analysis was conducted on five specimens with different levels of average plastic tensile strain assumed caused by different degrees of frost damage, matching those measured in a previous experimental study (Hasan et al 2004). The plastic tensile strains given to each specimen are distributed from zero to a value twice the average plastic tensile strain, or 0, 340, Stress-strain curves of the analytical models are compared with experimental data from…”

“…The method proposed by Nagai et al (2004), based on experiments conducted by Hsu and Slate (1963), Taylor and Broms (1964), Kosaka et al (1975) and Yoshimoto et al (1983), was used for the relationship between the material properties. The material parameters in Table 1 were chosen such that the compressive strength of undamaged concrete was near to the experimental value of 49.8 MPa (Hasan et al 2004). …”

Mesoscale Modeling of Chloride Penetration in Unsaturated Concrete Damaged by Freeze-Thaw Cycling

“…The volume increase and plastic strain derived from experimental data (Hasan et al 2004; 400 Jacobsen et al 1996) based on Eq. (26) are given in Table 2, together with their originally measured 401 results.…”