FEM Analysis of the Concrete Structure Life Under the Freezing and Thawing Cycles Conditions

The concrete will deteriorate after several freezing and thawing cycles, the deterioration degree gradually increases. The depth of freezing and thawing is changeable in different areas, dependent on the climate. Within the maximum depth, the concrete will not be affected by freezing-thawing cycles. Through the analysis of test data, this paper deduces a formula, reflecting the relationship between uniaxial compressive strength σ_c^d, the strength parameter σ^D E value, mass loss ^q, the elastic modulus E, poisson´s ratio μ, and concrete natural freeze-thaw cycle times N. This paper also deduces a formula, reflecting the relationship among the cohesion c, internal friction angle Φ value and concrete natural freeze-thaw cycle times N, uniaxial tensile strength f_t0, uniaxial compressive strength f_c0. This paper makes use of the formula for the calculation equivalent numbers of freezing-thawing cycles in laboratory,which can connect different freezing-thawing environments in laboratory and field. Having considered the bond strength of steel bar and concrete and deterioration of concrete under the freezing and thawing cycles condition, the FEM is applied to analyze stress/strain and yield of the concrete structure. Based on the calculation, the life of the concrete structure can be estimated.