Frost-salt Testing Non-air Entrained High-performance Fly-ash Concrete Part II: Parameter Study of Effect of Internal Cracking on Glue Spall Stress

A parametric analysis of glue spall stress (concrete surface tensile stress at ice-discontinuities by differential thermal expansion ice-concrete) as affected by internal cracking in concrete in the CEN/TS 12390-9 salt-frost slab-test was made. Increasing differential thermal expansion ice-concrete (triangle alpha) and reduced E-modulus and Poisson ratio (nu) due to internal cracking were used based on data from Part 1 of this study. For the concrete specimens in Part 1 of this study [1] glue spall stress increased by 14 % due to internal cracking whereas reduced ice thickness of 1 - 2 mm due to accelerated Liquid Uptake (LU) in wet freeze/thaw reduced glue spall stress by 34 to 65 %. LU should hence be accounted for in modelling scaling, both due to reduced ice thickness and increased triangle alpha due to internal cracking. Increased crack penetration depth and its effect on scaled particle size due to internal cracking were also analyzed.