Highway Machinery: - Road making plants and machinery is
used in various jobs. The various works included in the road construction are:
( Site Clearance: - The following tools and plants are
generally used for clearing the jungles, shrubs and clearing trees etc.
[1] BULL DOZER:-A bulldozer is a crawler (continuous tracked tractor) equipped with a
substantial metal plate (known as a blade) used to push
large quantities of soil,
sand, rubble, or other such material during construction or conversion work and typically equipped at the rear with a claw-like
device (known as a ripper) to loosen
densely compacted materials.
Bulldozers can be
found on a wide range of construction sites, mines and quarries, military bases, heavy industry factories, engineering projects and farms.
[2] TRACTOR: - It is important machinery which is used for different type sof works.
The tractor works with diesel engine having horse power varying from 20 to 200.
There are two types of tractors. First is Track type tractor and second is
Crawler type tractor.
The track or wheel
type tractors move on pneumatic tyres. This type of tractor is used ofr even
and smoothes country. The crawler type tractor moves on an endless chain and is
used for uneven and rough ground. Tractors are generally provided with various
attachments such as dozer, scraper, harrow; plough etc. tractors with various
attachments are used for cleaning the shrubs, roots etc. and for earth work in
formations. The tractor is primarily earth moving machinery.
[2] TOWED SCRAPER: - In civil engineering,
a wheel tractor-scraper is a piece of heavy equipment used for earthmoving. The rear part of the scraper has a vertically
moveable hopper with a sharp horizontal front edge which can be raised or lowered.
The front edge cuts into the soil, like a carpenter's plane cutting wood, and fills the
hopper. When the hopper is full it is raised, closed, and the scraper can
transport its load to the fill area where it is dumped.
[3] Shovel: - Shovel is the most powerful and giant
excavating machinery includes power shovels. It is one of the most versatile
equipment used in the construction of highways especially for earth work.
(B)
Sub Grade Preparation: - For cutting filling and preparing the formation or sub
grade for a road, the following machinery is used.
[1] Grader:- A grader, also commonly referred to as a road grader, a blade, a maintainer, or a motor grader, is a construction machine with
a long blade used to create a flat surface during the grading process.
In civil engineering, the grader's
purpose is to "finish grade" (to refine or set precisely). The
"rough grading" is performed by heavy equipment or engineering vehicles
such as scrapers and bulldozers.Graders are
commonly used in the construction and maintenance of dirt roads and gravel roads. In the construction of paved roads they are used to prepare the base course to create a wide flat surface upon which to place the asphalt.
[2] Trench Cutter:- A trencher is a piece of construction equipment used
to dig trenches,
especially for laying pipes or cables, for installing drainage,
or in preparation for trench warfare.
Trenchers may range in size from walk-behind models, to attachments for a skid loader or tractor,
to very heavy tracked heavy equipment. Trench cutters are five types.
(i)
Wheel Trencher. (ii) Chain Trencher (iii) Micro Trencher (iv) Portable Trencher
(v) Tractor Mount Trencher.
[3] Rollers: - It is one of the most essential
road making machinery. It was the only highway equipment used in India some few
years back. Rollers are generally self propelled but some of the rollers are
towed by tractors etc. the following are the common types or rollers which are
generally used.
(i) Cylindrical Roller: -
It is light roller of iron, concrete or stone, which is drawn by hand or
bullocks. These are available in various sizes and weights. Usual size is 100cm
in diameter and 150cm long. This roller exerts about 7.0 to 10.0kg/cm2
pressure on ground.
(ii) Flat Wheeled Roller: -
It is very common type roller and is commonly used. It can be driven by steam
or disel oil. The steam rollers have generally three wheels, a steering wheel
and two rear compaction wheel. The oil rollers have generally 2 wheels. A two
wheel roller is also called Tandem roller.
(iii) Pneumatic Roller: -
This roller consists of a small truck with two or more axles with a number of
pneumatic tyred wheels. The truck may be loaded so that the required intensity
of pressure may be attained. This type of roller is capable of consolidating
the surface slowly and uniformally, without causing damage to the aggregate.
(iv)
Sheep Foot Roller: - It consists of heavy metal cylinders usually of 1 to
1.5mt diameter and 1.2 to 1.5 mt long. Each of these drums has 16 to 18 cm
projections on their surface and each drum weighs about 3 to 4.5 tonnes.
Sheep foot rollers are used for
compacting fine grained soils such as heavy clays and silty clays. Sheep foot
rollers are used for compaction of soils in dams, embankments, sub grade layers
in pavements and rail road construction projects.
[4] Dragline: - A machine having a long crane boom and a
digging bucket for excavation of earth loading it into hauling units is termed
as dragline.
[5] Dumper: - Dumper is a lorry which can be emptied by
raising the front of the carrier to allow the contents to slide out from the
back.
(C)
Base Course & Sub Base Course Construction: - Equipments used in base
& sub base course construction are as:
[1] Crushers: - A crusher is a machine designed to reduce large rocks into smaller rocks, gravel,
or rock dust.
[2] Aggregate Distributor: - The
machine which is used for distributing the aggregates according to their sizes
is known as aggregate distributor.
(D)
Surface Course Construction: - For Flexible pavement:
[1] Hot Mix Plant: - A plant which is used for prepare
a premix bituminous concrete mixture to be laid over bituminous carpeted roads
in a desired ratio is termed as hot mix plant.
[2] Asphalt Mixer: - Asphalt Mixer is a machine or
plant used for preparing pre – mix bituminous material consisting of asphalt
and road aggregates to be used in bituminous carpeted road is known as asphalt
mixer.
[3] Bitumen Boiler: - The
machine used for supply hot bitumen at the required temperature in a continuous
system is known as bitumen boiler.
[4] Bitumen Sprayer: - The
machine which is used to spray or sprinkle bitumen on the surface in desired
quantity is known as bitumen sprayer.
For
Rigid Pavement:
[1] Concrete Mixer: - The
machine which is used for mixing of materials like aggregate, cement, water
properly to prepare concrete mixture is known as concrete mixer.
[2] Concrete Pavers: - The
machine which is used for to lay the concrete on the road or to making the
road’s wearing surface with proper compaction & finishing is known as
concrete paver.
[3] Vibrator: - Concrete vibrators consolidated
freshly poured concrete so that trapped air and excess water are released and
the concrete settles firmly in place in the framework.