ABSTRACT
The concrete surface layer is often referred to as its “skin.” According to Kreijger (1984), three types of concrete skin can be defined: the cement skin (about 0.1 mm thick), the mortar skin (about 5 mm thick), and the concrete skin (about 30 mm thick), as a result of the wall effect, sedimentation and segregation, compacting methods, and water bleeding. In terms of appearance and aesthetical appreciation, the “concrete skin” would be corresponding to a depth of one-half the maximum aggregate size (Dieryck et al., 2005), as shown in Figure 2.1.
