Concrete surface topography as a function of freeze-thaw exposure and abrasive blasting

This study investigated the topography of plain concrete during freeze-thaw exposure and following abrasive blasting. The independent variables included the water-cementitious material ratio (w/cm) (0.42, 0.50, or 0.56); the number of freeze-thaw cycles (100, 200, or 300); and the blasting method (dry ice or sand). Using the three-dimensional (3D) surface roughness as the response parameter, the analysis of variance (ANOVA) results indicated that the number of freeze-thaw cycles is most influential in governing the measured roughness due to both freezing and thawing and abrasive blasting. The statistical data indicate that the roughnesses created by the blasting methods are not significantly different, which suggests that both dry ice and sand produced equivalent surface topography. However, qualitative examinations revealed that sand blasting generated a relatively uniform surface, whereas dry ice blasting created localized damage in the form of pitting. This effect may stem from differences in the flow behavior and size of the particles prior to impact with the substrate.