Grey relativity correlations between the pore structures and compressive strength of aeolian sand concrete undergoing carbonation and freeze-thaw cycles

Abstract

In this study, the compressive strength of aeolian sand concrete (ASC) was predicted using pore structure parameters and pore structure types under the conditions of a complex environment. The relationships between the pore structures and the compressive strength of the ASC undergoing carbonation and freeze-thaw coupling actions were examined. Full ASC with a 100% replacement rate of aeolian sand (AS) was used in this study’s experiments. The microstructure characteristics of the ASC were analyzed using nuclear magnetic resonance (NMR) and scanning electron microscopy (SEM). At the same time, the correlation degrees of the pore structures and compressive strength were examined using a grey relativity analysis method. A GM (1, 3) prediction model of the ASC compressive strength under different carbonization times was established. The model showed that the effects of the carbonization and freeze-thaw cycles (FTCs) on the pore structures and the compressive strength of the ASC were different. According to the grey relativity analysis results, the bound fluid saturation and harmless pore ratios had the greatest impacts on the compressive strength of the ASC. The model established based on those factors had the ability to accurately predict the compressive strength of the ASC under the conditions of a carbonation-salt freezing and thawing environment.