Construction Machinery Assignment

MUHAMMAD ARSLAN, CIVIL ENGINEERING DEPARTMENT UET LAHORE

2007

Asphalt Plant

Asphalt is the most important ingredient for the construction of infrastructures like roads,

highways runway of airports etc. It is a durable petroleum product which is mixed or processed

either in stationary or mobile plants. Hot mix plants (both stationary and mobile), wet

macadam mix plant, asphalt mix plants etc are some of the asphalt based plants that are widely

used for the production of asphalts for various constructions.

Schemetic diagram

The asphalt plant uses a cold aggregate feeder whose each bin has an independent conveyor

belt. For feeding the aggregate at a uniform and predetermined rate it uses a hollow shaft

gearbox. The drum is supplied with cold aggregate from the feeder using an electronic high-

pressure jet burner. The asphalt tank is fully insulated and is equipped with separate low-


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pressure electronic burners to heat the asphalt. The control cabin with an electronic control

panel operates the entire plant. To transport the mixed material from the thermo drum into

the hydraulic storage hopper the asphalt plant uses a loadout hot conveyor. At the end of

conveyor there is a scraper plate to scrape out the mixed material from the loadout conveyor.

Mobile drum mix plant for bituminous macadam comprises of conveyor bitumen pump, a filler

unit and a filler blower.

Dozer

The term "dozer, refers to a tracked tractor fitted with a dozer blade. It is a heavy, driver-

operated machine for clearing and grading lands. The tracks gives bulldozer excellent ground

hold and mobility through very rough terrain. Came into existence in early 20th century it has

now undergone many modifications suiting to the requirements of the big infrastructural

projects.

Tractor, blade and rippers are the main parts of the bulldozer. Tractor is controlled by control

joystick, monitor panel, and pedals. Through blade it shaves the uneven ground and carries the

shaven soil along with it. While shaving, it levels and tighten the ground with its own weight.

Ripper on the other hand scratches the ground. Ripper can shave big rocks and hard grounds

also which the blade is unable to do.

Excavators

Excavators are multiple usage heavy engineering machines consisting of bucket, cab, backhoes

and are placed on tracks or wheels. Often the buckets are replaced by an auger, handler,

breaker or grapple as per demand and usage. Some of the excavators also have the small dozer

blade which is attached to the under carriage, for pushing removed materials back into hole.

Excavators are sometimes also called as 360 degree excavators


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Chain Excavators

Multipurpose and multi usage chain excavators with

their high potential for loading and performing big tasks are in great demand in the market, for

the accomplishment of big infrastructural projects. Based on their size and working principles

chain excavators can be categorized into bucket chain excavator, mini chain excavator and

hydraulic chain excavator. Though the basic functions of these three excavators are more or

less same, the difference lies in the magnitude of the work done by them.

Hydraulic chain excavator works more or less on the same principles on which hydraulic

excavator works. Whereas bucket chain excavators are important products designed for mining

the overburden and for the sticky bulk material. Supported by the scraper arm, the bucket

chain system, is suspended at a fixed angle from the bridge girders. Bridges are associated with

the stores which consists of two or more longitudinal stockpiles stacked according to the

windrow method. While one pile is being stacked, the other is reclaimed at right angles to the

direction of stacking.


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Wheeled Excavator

Wheel excavator is a multipurpose excavator which instead of a rotating platform has wheel in

the bottom. With improve stability on an uneven surface and improved lifting capacities it is

applied in various infrastructure projects likes roads, railways, bridges etc.

The wheeled excavators have heavy-duty axles and a two-speed transmission system, which

enhances their movements and stability in an uneven areas. With their rotating arm they can

reach out to all directions without any problems. The wheeled excavators also consists of

backfill blades, independent boom swing, Counter rotating tracks, arm, bucket, mounted cab,

swing motor, power boost and Lcd display which gives them an extra advantage during their

involvement in heavy projects

Loaders Loader, is a machine usually wheeled, that uses a wide tilting bucket on the end of movable arms to lift and move materials. Often the bucket can be replaced with other device depending on the nature of the work. For example buckets are sometimes replaced by depending on the nature of the work. For example buckets are sometimes replaced by clamshell or forks for doing certain tasks .Wheel loaders due to their versatility and sophisticated technologies are used in following areas :

Digging construction sites. Lifting of devices and materials. Used in the transportation of various dry materials. Helps in the construction of roads and other buildings.


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It fills and removes various granular substance and solid materials from rail cars, hoppers etc.

It is also sometimes used for the light demolitions.

Loader

Paver

For giving final finish to pavement surfaces, paver finisher is an important equipment.

Tractor and the screed unit are two important components of the typical paver machine.

This paver is suitable for various asphalt surfaces. Asphalt paver finisher machine consists of

the screed, which is attached through two long side arms or leveling arms at tow points of

the tractor, one on either side. The screed is not fixed but is free to pivot about tow points.

The screed is towed by the tractor. The tractors are either wheel mounted or track

mounted.


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This paver also consists of the hopper operations, screed lifting and vibrating arrangements

and is hydraulically controlled. The width of the screed can be mechanically adjusted with

mechanical bolt on extensions on either side. Whereas conveyor and auger drive adjusts the

feed to the desired level. Screeds are of different types like combination screed, vibratory

screed, tamping screed etc.

Paver finisher is applied in giving final paving touch to :

Roads Highways Runway of airports Pavements both asphalt and concrete Concrete roads Canal pavings etc

Rollers

Road roller is an important engineering vehicle that is considered necessary for the

roads and highway constructions and is used for the compaction of dirt, gravel,

concrete, and asphalt. In landfill compaction too, road roller has great utility. The size

vary according to the usage. Its size vary from simple drum with a handle, to a size of

many tonnes


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Smooth tyred roller Pneumatic Tyred roller

Sheep foot roller

The major utility of rollers lies in the following areas :

Compaction of roads. Compaction of runways in airports. It also has utility in the landfill compaction. It is also used in the compaction of car parking areas, pavements etc.

Asphalt Container

Asphalt thermo containers are those machines that processed asphalt to be used in the

construction, maintenance and repairing of roads. The modern thermo containers using

effective technologies are economic and environment friendly.

Asphalt containers are either single chambered or double chambered. However double

chambered container is widely used. To maintain the asphalt at the necessary working


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temperature, the chambers are heated with an environmentally friendly propane gas

burner. To prevent the asphalt from cooling, the chamber is provided with insulation. In

some container there is an option of electrical heating. Conveyor fitted in the container is

applied for spreading the material.

Concrete transit mixer

It is used to trasnsport concrete from plant to site. It keeps on revolving on a certain

rpm which prevents concrete from settling.

Mobile Water Tanks

Mobile water tank is also a very important machienery used in construction. It is used to

carry water for various purposes on the site.


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Mobile water tank

Documents

Construction Machinery Assignment