A variety of equipment is used
for soil compaction. A road roller is one of the main items of equipment in
this category that is used extensively for road construction. A road grader is
also used in combination with the road roller for soil leveling.
There are numerous
requirements where it is essential to produce a level and equally compacted
ground surface. Generally, soil compaction is required for the improvement of
the subsurface and the surface finish of a road. Consistency in compaction and
the surface smoothness are particularly important for roads that are to be used
for heavy traffic. Non-uniform and improper compaction may create irregular and
extensive surface wear. A soil moisture content analysis would be essential
prior to the road construction. An irregular road surface produced due to
uneven wear or by insufficient smoothing will cause fast deterioration of the
road surface. Normally, a road is constructed with the foundation consisting of
comparatively larger stones. The intermediary layer consists of the binder and
small stones, and the surface layer consists of bituminous substances. As each
of the layers is positioned, it is compacted and flattened by a road grader and
a road roller. Safety on road construction work is of utmost importance to
prevent accidents.
Basically, the roller drum
weight is used for the compression of the surface required to be compacted. The
initial compaction is obtained by the use of roller with tires. The wheels are
flexible to attain some vertical movement that enables the roller to operate
efficiently on an irregular ground surface. Subsequently, the final road
surface finish is obtained by the use of rollers with metal drums. Road rollers
are also used for the compaction of landfills. Such rollers have knobbed wheels
and are used when a perfectly smooth surface is not required.
Road rollers consist of two or
more big heavy drums, with one drum being driven and provide the pushing force.
The other drum is pivoted, and connected to the roller body. It is rotated to
guide the roller to the chosen pathway. In some rollers, the drum axles move in
relation to each other to adjust for the surface irregularities. Different
compacting and smoothening equipment is used with rollers for road construction
operations. Normally, a road roller consists of roller units at the front and
rear, with a hydraulic steering system. On some equipment, the roller drums are
water filled to attain the weight desired for compaction of the road surface. Compaction
can be increased by using vibrating roller drums that enables a smaller machine
to achieve the same compactness as by a larger roller. Vibration is normally
obtained by eccentric weights that are attached to the shaft of a motor located
in the roller drum. The drum surface is lubricated by water for the prevention
of asphalt being affixed with the drum surface. The other parts of a roller are
a diesel engine, a driver canopy, a compaction gauge to determine the intensity
of compaction, and a water supply system.
The roller kind that is
suitable for a particular application is generally dependent on the nature of
construction materials being utilized, the soil conditions, the moisture
content, and the weight required to achieve the desired compaction. The road
roller should ensure that the foundations are properly compacted so that the
materials do not become loose. The road rollers generally used are the static
weight rollers that have an even steel cylinder, with a single axle. Compaction
is achieved by forcing the soil upwards in the movement path. Other kind
normally used is the three wheel roller that is suitable for compaction of
bituminous materials in fine layers. It has a large roller at the front and two
small rollers at the rear. The front drum is steered, while the rear rollers
are driven. It is useful due to its capability to manage considerable surface
areas.