What does Road roller Truck mean?
Road roller Truck (sometimes called a roller-compactor, or just roller) is a compactor-type engineering vehicle used to compact soil, gravel, concrete, or asphalt in the construction of roads and foundations. Similar rollers are used also at landfills or in agriculture. Road roller Truck are frequently referred to as steamrollers, regardless of their method of propulsion.
Types of Road roller Truck:
- Cylindrical Rollers.
- Grid Rollers.
- Pneumatic Tyred Rollers.
- Sheepsfoot.
- Smooth Wheeled or Static Rollers.
- Single Drum Rollers.
- Double Drum Rollers.
- Vibratory Rollers.
1. Cylindrical Road roller Truck
This is a prosaic style of a roller, which is lightweight and may be handled by the blue-collar or by domiciliary creatures. It is usually assembled by iron, concrete, or stone.It generally estimates around 1 m in diameter and 1.5 m long & generated ground pressure is around 7kg/cm2.
2. Grid Rollers
They encompass a network of grid-like steel bars which can even be ballasted with concrete blocks or steel adjuncts. These sorts of rollers are generally towed or pulled behind a tractor at speeds amidst 5 & 24 km/h
The grid design churns out a high contact pressure with bijou kneading venture on compaction job. They are most fitted on well-graded, boorish soils, disintegrated rocks, and for sub-grade and sub-base road constructions.
3. Pneumatic Tyred Rollers
Pneumatic rollers are colossal, ride-on roller with series of rubber tires at the front or at the occiput part. The rubber tyre supplies 80% coverage area & invariable pressure disseminated throughout the breadth of the tires.
They are typically utilized for highways, streets, dams and might aid to shine a project, but additionally are extraordinary for cold-laid bituminous veneers & veneers of loose soil.The pneumatic roller has the ductility to exercise contact pressure ranges from 500 – 700 Kpa or 7k g/cm2. The weight of the roller is 6-10 tonnes which are surged to 25 tonnes by ballasting.
The utmost bulk is acquired by 8 passes & the optimum speed of the roller retains somewhere between 6-24 km/h.
4. Sheepsfoot Road roller Truck
Sheepsfoot rollers are occasionally called padfoot or tamping rollers. They have innumerable rectangular-shaped lugs or “feet.” They’re adept in compacting soil & silty clay during a construction job.
The sheepsfoot drum’s weight might be surged by ballasting (with water, damp sand, or mounting steel sections). The area of each & every portion can range from 30 to 80 cm2. About 10-20 passes are required to provide thorough coverage.
Coverage Area is about 8-12 % because of boots on drums. Contact Pressure ranges from 1200-7000 Kpa. The soupiness of compacting layer is about 5 cm extra the length of every foot.
The factors that govern the quantity of compaction of soil are given subsequently:-
- The aggregate weight of the roller.
- Area of every lug.
- No of feet or lugs in touch with the ground.
- Total no of lugs per drum.
- Paramount pressure exercised on the soil when a foot is vertical.
- The density of the blended soil should be about 1.48 kg/cm3.
- Pressure on the feet maybe 4 to 7 kg/cm2 for light rollers and up to 25-70 kg/cm2 for brobdingnagian rollers.
5. Smooth Wheeled or Static Rollers
There are 2 kinds of smooth wheeled rollers: single & double drum roller. They are again noted as static rollers. Smooth wheel roller and vibratory rollers are basically alike. Both have identical features. There’s just one point of distinction, i.e., vibratory equipment. Smooth wheel roller has no vibrator attached and is best suited to rolling of fragile aggregates and in compacting asphalt pavements.
5.1. Double Drum or Tandem Roller
The tandem, or double drum roller, has one steel drum at the front and another at the rear. As soon as the two drums move, the Road roller Truck moves. These Road roller Truck are adept in compacting silty or sandy or flat soil with gradual surfaces like asphalt but are not nominated for any distinctive job.
According to the number of wheels on the rear, it is of subsequent two types:
Tandem rollers (having one wheel at the rear and one wheel in front)
Three-wheeled rollers (having two wheels at the rear and one in front)
Traveling across Quang Binh to stunning cinematic locations .The weight of the tandem roller varies from 2 to 8 tonnes, and the two-wheeled roller ranges from 8 to 10 tonnes.
5.2. Single Drum or Three-wheeled Roller
They possess a steel drum at the front & 2 special wheels at the rear. Single drum rollers can toil at tighter spaces due to their bijou size. They are adept at creating foundations for buildings and paving highways or sidewalks.
The ground coverage is 100%. The pondage of the roller is surged by filling the within space of the drum with water or wet sand. This process is named ballasting. The ground pressure exercised by tandem rollers is about 10 to 17 kg/cm2.
The optimum working speed has been found to be 3 to 6 km/h, and about eight passes are ample for compacting 20 cm layer. Smooth wheel rollers are most fitted for blending stone soling, gravel, sand, hardcore, ballast & surface dressings. The paramount grade a road roller can climb is 1 in 5.
6. Vibratory Rollers
Vibratory rollers are nearly indistinguishable from smoothing wheel rollers aside from one major distinction: i.e., the vibrating component. Since soil, asphalt, and concrete have natural bare spaces, they will cause a vandalization to the structure of the building.
Employing a vibratory roller retains the building’s structural integrity. This style of the roller is usually fitted with 1 or 2 smooth surfaced steel wheels 0.9 m to 1.5 m in diameter and 1.2 m to 1.8 m wide.
Self-propelled vibratory rollers are now obtainable pounding from 4 to 6 tonnes. Vibrations are generally generated by the swiveling of an eccentric crankshaft present within it.
Vibratory rollers are utilized for compacting granular base courses. It’s frequently utilized for asphaltic concrete jobs. They have higher outputs and improved performance juxtaposed to other rollers but also generally come at a lofty cost.
Advantages and Disadvantages of Road roller Truck
| Advantages | Disadvantages |
| Brisk placement. | Reveling of cracks. |
| Shorter haul distance. | Adept workers are required. |
| Heat isn’t evolved during the dehydrating of concrete. | Smoothness is onerous to attain. |
| Road roller Truck concrete requires the minutest nurture. | Dams constructed or renovated with Road roller Truck concrete may undergo water leakage. |
| Also, it reduces cement consumption as lissom concrete blends are also used. | In Road roller Truck compacted concrete dams, the drainage gallery often surges construction time and additionally surges costs. |
| The cost of formwork is diminished or eradicated due to the layer placement method. | Although it’s accustomed to design RCC dams efficiently, in comparison to other dams because of the low-cost option, there are situations which will make RCC costlier. |
