Racked-in surface dressing

The advantages of this method are high initial texture depth, early stability of dressings and major reduction in the initial loss of large chippings. The RISD is mainly used where traffic is heavy or fast. 

---

Figure 15.23 Types of surface dressing, (a) Single surface dressing (b) racked-in surface dressing (c) double dressing (d) inverted double dressing and (e) sandwich dressing (example of pre-chippIng dressing). (Reproduced from CEN EN 12271, Surface dressing - Requirements, Brussels CEN, 2006. With permission [ CEN].)...

Racked-in surface dressing (RISD) (Figure 15.23b) refers to successive laying of one layer of binder and two layers of chippings, the second layer being of a smaller size. 

---