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Abstract:
This paper features the development of a probabilistic model linking freeze–thaw (F-T) performance of concrete mixtures to their composition. A sensitivity analysis was performed on several concrete mixture parameters to identify the factors that have strong correlations with F-T resistance of concrete. The F-T performance level was defined as a discrete measure of the frost resistance of concrete. Finally, a new model to predict F-T damage incorporating the variability in concrete mix parameters (as selected from sensitivity analysis) was developed. This model was developed using only those data sets that contained the results of the relative dynamic modulus of elasticity (RDME) testing performed according to ASTM and AASHTO specifications. Concrete mixtures containing only ordinary portland cement (OPC) as the sole binder (i.e., mixtures that did not contain any supplementary cementitious materials) were considered. The reliability of the model was demonstrated using several examples of concrete mixtures of various compositions. Accordingly, this model provides the opportunity to optimize the concrete mix proportion for the required performance level of concrete under F-T exposure condition.

Keywords:
Freeze–thaw, Durability, Concrete, Pavement, Sensitivity analysis, Probabilistic design

Abstract:
This paper features the development of a probabilistic model linking freeze-thaw (F-T) performance of concrete mixtures to their composition. As part of the process of model development, a sensitivity analysis was performed on several concrete mixture parameters to identify these factors that have strong correlations with the F-T resistance of concrete. This sensitivity analysis was performed on 128 sets of experimental F-T test results collected from the literature. The F-T performance level was defined as a discrete measure of the frost resistance of concrete. Finally, a new model to predict the F-T damage of concrete incorporating the variability of the concrete mix parameters (as selected from sensitivity analysis) was developed. This model was developed using only these data sets which contained the results of the relative dynamic modulus of elasticity (RDME) testing performed according to the ASTM C 666 (AASHTO T 161) specifications. Furthermore, only mixtures containing ordinary portland cement (OPC) as a sole type of the binder (i.e., mixtures that did not contain any supplementary cementitious materials) were considered. Additional experimental test results were utilized to validate the model. The reliability of the model was further demonstrated using several examples 1 of concrete mixtures of various compositions. Furthermore, the effects of the number of F-T cycles, air content, paste content, and w/c ratio on the F-T performance of the concrete mixes were demonstrated using the developed model. Accordingly, this model provides the opportunity to optimize the concrete mix proportion for the required performance level of concrete under F-T exposure condition.

Keywords:
Freeze-thaw, durability, concrete, pavement, sensitivity analysis, probabilistic design