Question: Do you know if the drying shrinkage properties of concrete with integral oxide pigment are different when compared to plain grey? Are there any changes to water demand or strength for concrete with pigment? Are particular colors more susceptible to cracking in the medium- to long-term?
Answer: We aren't aware that integrally colored concrete has significantly different shrinkage properties than the same concrete would have without the color, although there would be a very small water demand to wet the pigment. The only shrinkage issue could possibly be with darker colors on a hot sunny day. The surface of colored concrete under these conditions could take initial set before the matrix. Drying shrinkage and surface crusting could result.