Road Constuction Method
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Transcript of Road Constuction Method
ROAD CONSTUCTION METHODSPRESENTED BY
GROUP 5Himgiri Yadav Kamal nabh tripathi Mohd. Sharique Pervez Mamta Supriya Pal
Road is a pathway used by the people to
travel from one place to other in a shortest possible way with maximum riding comfort.
It contribute in the following ways:It contribute to the economic development. It contribute to the industrial development. It help in the social and cultural development. It interconnect all area and thus facilitate us to travel from one place to other.
We need because of the: Demand for transport infrastructure is rising by around 10% a year. India has 1% of traffic and about 8% of worlds fatalities. Average bus speed in metro cities is about 1012km/hr. Automobile sector area increases from 6.3 million in 2002-2003 to 11.2 million in 20082009.
Traffic is increasing very fast
Various method under this heading are: Earth road method. Gravel road method. Water Bound Macadam method. Bituminous method. Concrete Cement road method.
It mainly consist of mainly earth as raw material which is to be compacted. It is the cheapest type of road prepared from natural soil. It has high camber and cross slope to avoid erosion due to water in rainy season.
It consist of :Clearing of site . Excavation and construction of fills to bring the road to a desired grade. Shaping the subgrade. Then the borrowed soil (it consist of mixture of two or more near soil) is dump on the subgrade and well compacted ,depth not exceed 10 cm . Make the soil upto O.M.C level. After this it is allowed to dry for few days before opening to traffic.
It has following merits:y It is cheap. y It has easy construction. y It can be build with less skill.
Its demerits contains: It has low bearing capacity . Mainly for poor places. It get eroded vary quickly. It become slippery when wet.
It mainly consist of crushed stone as their raw material. It is superior to earth road . It consist of two method: A. Feather edge type:- In this the subgrade is uneven and the construction is done over it to obtain the desired cross slope.B.
Trench type:- In this subgrade is preparedby excavating a shallow trench.
It consist of the : Clean the area. Make the subgrade upto desired cross slope. Crushed gravel aggregates are placed carefully in the trench so as to avoid segregation . Provide proper camber. Some water may be used to make there compaction effective. Left for few days before opening.
Its demerits are: It does not provide comfortable ride. It become detereoted very soon. It can not hold very heavy traffic. It can not hold rain.
Its merits are: It is superior to earth road. It does not become slippery when wet. It maintenance coast is low. It can hold medium traffic. It is easily constructed. It is cheap.
It was develop by the John Macadam(1756-1836)and was first person to suggest that heavy foundation stones are not at all necessary to be placed at the bottom layer of construction . y He uses water as the binding material. y He uses different grades of stone for different layer. Important Introduction sub grade drainage Good compaction. It uses scientific knowledge which says that in flexible pavement stress is transfer by grain to grain or layer to layer method.y
It consist of the following procedure: Preparation of foundation for receiving the WBM coarse. Spreading of coarse aggregates. Rolling and compaction. Sprinkling and Grouting . Binding materials application. Setting and Drying. Checking of surface evenness and Rectification of defects.
It has following merits: It provide base coarse for top surface. It can be used with little care. It is a cheap method. It introduce the concept of sub-base drainage.
It has following demerits:It detereoted very easily. It can not be used without surface covering. It aggregates get loose when water loose from them.
is the most common type of road construction. It main purpose is to protect the sub-base coarse from wearing and tearing and to provide a smooth riding comfort. It has no. of method. They are: It
1. Bituminous surface dressing:- It is provided over an existing surface to serve as thin wearing coat. It serve as water proof pavement. Dust proof in wet season and mud proof in wet season.
It is used as a base or binder coarse. In this bitumen is used as a cementing material to bind the aggregates and as a filler to fill the void. 3. : It consist of two layer composite construction of compacted crushed aggregates with application of bituminous binder after each layer for bonding and finished with key aggregates at the top to provide a total compacted thickness of 75mm. : it is premixed construction method consisting of one or more coarse of compacted crushed aggregates premixed with bituminous binder . It consist of thickness of 75mm. It should be cover with suitable cover.2.
It consist of coarse aggregates of 12.5 and 10mm size premixed with bitumen and composed to a thickness of about 20mm. It should be covered by a suitable seal coat. It aggregates consist of size between 20mm to 6.3mm. it is a dense graded premixed bituminous mixture which is well compacted to form a high quality pavement surface course. Thickness ranges from 90 to 75mm. IRC has provided specification for 40mm thick bituminous concrete surface coarse for highway construction.
All method has nearly same construction procedure. Common steps to all the methods are:Preparation of existing surface . Spreading of coarse aggregates. Rolling . Seal coat / Track coat. Surfacing finishing . Opening of traffic.
It has following merits:It is cheap. It provide good riding comfort. It hold the aggregates well. It prevent the wearing of sub-base.
It has following demerits: It get detereoted. It design life in not long. It require frequent maintenance for heavy traffic.y
It mainly consist of concrete & cement in its construction. It has nearly same concept of laying road slab as in the building slab. CC construction can be divided into :1. Construction of pavement slab:- In this we are concern about the construction of the road slab. 2. Construction of joints:- In this we are concern about the construction of the joints between the road the slab.
CC has two modes of construction which are:1. Alternate bay method :- In this we make alternate block of CC on the both lane in the same time , leaving gaps between them. It is usually not prefer today's. 2. Continuous bay method :- In this we make a lane upto certain length and the next lane is completed afterward. This is now days in practice.y
It has the following steps: Preparation of
subgrade & sub-base . It include-
1. 2. 3.
Moist the sub-base in advance of placing concrete. Sub-base should be well compacted and does not contain any soft spot. It should have proper drained facility. Placing of forms- Steel and wooden forms should be properly connected to the slab. Batching of materials in this the aggregates are
graded to calculate the amount of cement require. Placing of concrete in this the concrete is properly placed over the sub-base. Compacting and Finishing in this concrete is compacted with the help of vibrator. It has two methodFloating and Straight edges. Belting, Brooming and Edging.
this concrete is kept moist for about 28 days. It has two types:A. Initial curing. B. Final curing
Colure full cement
Cement-concrete road Cement-
give best riding comfort. It is long design life. Further all the characteristic of road can be easily predicted. It can bear any type of load. It does not get easily detereoted. It has sufficient friction both in wet and dry condition. It
It has high initial cost. y It maintenance coast is high. y It require time for completion. y It require great skill. y It maintenance time is also large.y