construction of roads presentations

Construction Of Roads

Construction Of Roads

Group MembersMuhammad Ijaz 12-

CE-24Asif Aziz 12-

CE-48Shahbaz Ahmed 12-

CE-132

ContentsIntroductionClassification of RoadsMaterials Used In Road ConstructionMachinery Used In Road

ConstructionMaintenance And Rehabilitation

IntroductionA line of communication (travelled way) using a

stabilized base open to public traffic, primarily for the use of road motor vehicles including "bridges, tunnels, supporting structures junctions, crossings and toll roads.

A 1984 ruling said "the land over which a public right of way exists is known as a highway.

Ways that allow the movement of motor-vehicles, and the term rights of ways can be used to cover the wider usage.

Classification Of RoadsNational Highways Important roads &connect state capitals, ports

and foreign highways. They also include roads of military importance. They are financed by the central government.

State Highways Connect important cities and district head

quarters in the state, national highways & state highways of neighbouring states. Financed by state government roads and buildings department.

District Roads These are the roads within a district. i) Major District Roads ii) Minor District Roads

Village Roads They connect villages with each other

and to the nearest district road.

Road Structure Road Structure Depends Upon the key What is it

for!There are two main types of pavement (road

structure) i) Flexible Roads ii) Rigid Roads

Flexible Carriageway Construction When a road is built, the surface is dug-out down

to the designed depth of the intended road. The sub-grade is the ground below the road layers which is exposed once the ground has been dug out ready to build the road.

--------------------------------------Surface Course

--------------------------------------Binder Course

--------------------------------------Base

--------------------------------------Sub - Base

--------------------------------------Capping

- - - - - - - - - - - - - - - - Sub – Grade

Rigid Road Construction:Rigid pavement is the technical term for any

road surface made of concrete. The largest advantages to using concrete

pavement are in its durability and ability to hold a shape.

A surface layer, made up of slabs of Portland cement concrete (PCC), sits on top of a handful of sub-layers.

The layer directly under the PCC is more flexible than the concrete, but still quite rigid.

Materials Used In Road Construction1.Asphalt Asphalt also known as bitumen  is a sticky, black

and highly  viscous liquid or semi-solid form of petroleum.

Asphalt is used in road construction, where it is used as the glue or binder mixed with aggregate  particles to create asphalt concrete.

It is use to prepare asphalt emulsion, Hot mix asphalt concrete, cold mix asphalt concrete.

Aggregates1.Granite aggregates are crushed hard rock of

granular structure, being the most common on Earth.

Fractions of Aggregates0-5mm the smallest granite aggregates fractions

are used, besides the road construction, for decoration and paving paths, for covering sports grounds.

5-10mm fraction, is used for road construction and production of concrete.

10-40mm a road sub base also used for road maintenance operations.

2.Gravel aggregates are aggregates acquired as the result of sifting quarried rock and by crushing natural stone rock.

3. Limestone aggregates are a product of the crushing of sedimentary rock - limestone, which is composed mainly of calcite (calcium carbonate ).

4.Slag Aggregates are obtained by crushing of smelter slag or by special treatment of fire-liquid slag melt (molten slag aggregates).

Machinery used in Road ConstructionMachinery used in road constructions are used

for rough grading, fine grading, surfacing, paving, compaction and to control moisture level.

AIR-TRACK DRILL A drilling machine for quarry or opencast

blasting equipped with tracks and operated by independent air motors.

 AIR-TRACK DRILL

CHIP SPREADERA chip spreader lays down the aggregate on

top of a bituminous binder which is then rolled by a compactor.

COLD PLANERSA cold planer (also known as a pavement

planer, pavement recycler, mill or asphalt milling machine) is a machine used to remove bituminous pavement or asphalt concrete from roadways.

CompactorsUsed for compactions

Vibratory Steel Drum compactorVibratory roller compactor is used to compact

soil, gravel, concrete, or asphalt in the construction of roads and foundations.

Pneumatic tired rollerPneumatic tire compactors are used on small

to medium size compaction jobs, primarily on bladed, granular base materials.

Padded Drum CompactorPadded drum compactors are usually applied

to compact soil, gravel, concrete, or asphalt in the construction of roads and foundations.

OIL DISTRIBUTORSAsphalt distributors are used to apply prime

or tack coats on a surface in preparation for paving.

PAVERA paver is a machine used to lay asphalt on

roadways. It is normally fed by a dump truck which brings hot asphalt.

Maintenance and RehabilitationRoads are exposed to tremendous loads that

will sooner or later leave their marks on them. A time will come when every road will be in need of a general overhaul. Following methods are used.

Replacing the Pavement By removing only those layers of a road

structure that are actually damaged.Additional conditions frequently stipulate that

the flow of traffic must be maintained in spite of extensive reconstruction measures.

Replacing the Pavement

Paving thin Layer HotPaving thin layers in hot application is a viable

option for rehabilitating of Limited damaged roads.

At first surface deformations are removed by cold milling machines fitted with fine milling drums to create an even, slightly roughened road surface.

When using a paver with integrated spray module, the paver seals the base by spraying a tack coat of polymer-modified bitumen emulsion with a minimum bitumen content of 60% .

Paving thin layers ColdFast and economically efficient alternative to

replacing the entire road pavement.Traffic safety is hazarded when the road

surface gets slippery, when wheel ruts have dug into the pavement, or when the road is covered with bumps and deformations.

Cold milling machines fitted with fine milling drums prepare the road surface for application of the thin, cold pavement layer.

It works at a maximum milling depth of 50 mm, reprofiling the pavement by means of modern levelling technology to produce a level surface. The slightly roughened surface texture produced by fine milling offers.

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