WBM Stands for Water Bound Macadam, which is the most used road construction procedure for over 190 years. Created by Scottish engineer John Loudon McAdam around 1820 Macadam is a type of road construction. The broken stones of the base and the course of the surface, if any is bound by stone dust is the presence of moisture is called WBM Roads.
Macadam means the path of the base of the pavement made of crushed or crushed aggregate mechanically entangled by lamination and the holes filled with binding and binding material with the help of water. The WBM can be used as a secondary base, base or surface course. each compacted WBM layer ranges from 10 cm to 7.5 cm, depending on the size and gradation of the aggregate used.
Construction Procedure:
1. Prepare the basis for receiving the WBM course.
2. The lateral confinement can be made by compacting the shoulder to advance, to a thickness equal to that of the compacted WBM layer and trimming the inner side vertically.
3. Spacing of coarse aggregates.
4. The compacting of the coarse aggregate is carried out by means of a rolling power roller of capacity of 6 to 10 tons or alternatively with an equivalent vibratory roller.
5. The drying sieving is applied gradually over the surface to fill the gaps in them.
6. The surface is sprayed with water, swept and rolled.
7. The bonding material is applied at a uniform and slow rate to two and more layers.
8.WBM Thick is allowed to set overnight.