Color control:
The gray of cement
Interview with Dr. Peter Boos, director of Heidelberg
Cement’s central laboratory in Ennigerloh, Germany
Why is cement gray?
Dr. Peter Boos: This is actually based on the question of why materials have a color. The answer is because they reflect and absorb different degrees of light. If a material completely absorbs light, it appears black; if it reflects all of the light, it appears white. If it only absorbs or reflects certain wavelengthsof light, it appearscolored. The gray of cement sits between the two extremes of white and black.
Where does the gray come from?
Cement essentially consists...
