Color and mechanical property degradation of blue concrete under freeze-thaw cycles: An experimental study

Colored concrete is widely used in pavements of theme parks and its mechanical and aesthetic behaviors could be affected by freeze-thaw cycles (FTCs). In this study, experimentations were carried out to reveal the deterioration mechanism of typical blue concrete under FTCs. Ten cases of blue concrete in different colorant dosages were prepared to study the effect of curing age and FTCs. The results showed that water-based colorants improved the color stability due to the increased surface colorant molecular density. Furthermore, the strength loss under FTCs and maximum crack width significantly reduced due to the existence of small molecules of phthalocyanine that can enhance density and crack resistance. However, water-based colorants may reduce the mechanical properties of blue concrete. The incorporation of body colorants in blue concrete can enhance the flexural and compressive strengths of blue concrete by 26.7–212.9% and 20.1–40.5%, respectively, due to the rehydration of white cement that can recover the frost damage. Additionally, they also can maintain the color due to the ability of titanium dioxide which can cover the original color of concrete.