6 TYPES OF ROLLERS USED FOR CONSTRUCTION WORK

 Types Of Rollers

Rollers are the construction equipment used for the compaction of soil, sand, gravel and crushed stone etc.There are mainly 6 types of rollers:

1. Cylindrical Rollers
2. Sheepsfoot Rollers
3. Vibratory Rollers
4. Pneumatic Rollers
5. Smooth Wheeled Rollers
6. Grid Rollers

1. Cylindrical Rollers

Cylindrical rollers are light weight roller and are pushed by a person.The size varies but it is generally about 1 meter in diameter and about 1.5 meter long.These rollers are used mainly for small and private projects.It is made of iron, stone or concrete.The ground pressure generated by this type of roller is about 7 kg/cm2.

2. Sheepsfoot Rollers

Sheepsfoot rollers is also known as padfoot or tamping rollers.It consists of a drum having many round or rectangular shaped feet or lugs on it.It is available in different diameters and width of drum and different lengths and shapes of feet.Sheepsfoot rollers are good for compacting cohesive soils and silty clay in road construction work.

3. Vibratory Rollers

Vibratory rollers are most commonly used road rollers.This type of roller are fitted with one or two surface steel wheels 0.9 to 1.5 m in diameter and 1.2 m to 1.8 m in width.A vibratory roller is used for compacting granular base courses.It sometimes used for asphaltic concrete work.Self propelled vibratory rollers are now available weighing from 4 to 6 tonnes.

4. Pneumatic Rollers

Pneumatic roller has a number of rubber tires at the front and at the rear end. Empty spaces left in between the two tires that make 80% coverage area under the wheels. Pneumatic roller has the ability to exert contact pressure ranges from 500 - 700 Kpa. Pneumatic tired roller can be used for highways, construction of dams and for both fine grained and non-cohesive soils.It is also for smoothening of finishing bitumen layer on highways, roads, streets etc.

5. Smooth Wheeled Rollers

Smooth wheeled rollers consists of a large steel drum in front and one or two wheels or drum on the rear end.These are either tandem or three wheel rollers. Smooth wheel rollers are ideal for gravel, sand, ballast and surface dressings. They are not effective in compacting embankments and softer turf, but they are the most effective in compacting silty or sandy soils with the fewest passes. The weight of tandem roller varies from 2 to 8 tonnes and that of two wheeled roller varies from 8 to 10 tonnes. The ground pressure exerted by tandem rollers is about 10 to 17 kg/cm2

6. Grid Rollers

Grid rollers have a cylindrical heavy steel roller consisting of a network of steel bars coming together to form a grid like pattern. The grid may also be ballasted with concrete blocks for additional contact pressure. These rollers are ideal for compacting most coarse grained soils, since they provide little kneading action with high contact pressure. They are generally towed units and can operate at speeds between 5 and 24 km/hr and its weight varies between 5 tonnes net and 15 tones ballasted.