Rollers

Presentation on types of rollers and description about them in short .

1. Rollers By: AMAN KUMAR SINGH

2. INTRODUCTION A road roller  (sometimes called a  roller -compactor) is a compactor type engineering vehicle used to compact soil, gravel, concrete, or asphalt in the construction of  roads  and foundations.

3. TYPES OF ROLLER s Smooth Wheeled Rollers Smooth wheeled rollers are of two types: Static smooth wheeled rollers Vibrating smooth wheeled rollers Sheepsfoot Rollers Pneumatic-Tired Rollers Grid Rollers Tamping Rollers Padded drum vibratory rollers

4. Smooth Wheeled Rollers 1 . Static smooth wheeled rollers The smooth wheeled rollers consists of one large steel drum in front and two steel drums on the rear. The gross weight of these rollers is in the range of 8-10 tonnes(18000 to 22000 lbs).

5. Smooth Wheeled Rollers 2. Vibrating smooth wheeled   It comes in two models single or dual drum models. The drums are made to vibrate by employing rotating or reciprocating mass which generate three compactive forces: 1)pressure,2)impact,3)viberation .

6. Sheepsfoot Rollers Sheepsfoot rollers are used for compacting fine grained soils such as heavy clays and silty clays. The weight of drums can be increased by the use of ballast in the drum which varies the foot contact pressure.

7. Pneumatic-Tired Rollers Pneumatic tired rollers are also called as rubber tired rollers. These rollers are used for compaction of coarse grained soils with some fines. The total weight of the roller can be increased from 11.0 tonnes to 25.0 tonnes or more by ballasting with steel sections or other means.

8. Grid Rollers   These rollers have a cylindrical heavy steel surface consisting of a network of steel bars forming a grid with squire holes. Typical weights vary between 5.5 tonnes net and 15 tonnes ballasted. Grid rollers provide high contact pressure but little kneading action and are suitable for compacting most coarse grained soils.

9. Tamping Rollers These rollers operate at high speeds, and are capable to breaking large lumps. These rollers also consists of leveling blades to spread the material. These rollers are similar to sheepsfoot rollers with lugs of larger area than sheepsfoot rollers. The degree of compaction achieved is more than sheepsfoot rollers. 

10. Padded drum vibratory rollers These rollers are effective on soils. The edges of the pads are rolled inward enabling them to walk out of the lift without fluffing the soil.

11. Thank you