Project Report on Road Construction -Development of a country depends on the connectivity of various places with adequate road network. Roads are the major channel of transportation for carrying goods and passengers. They play a significant role in improving the socio-economic standards of a region. Roads constitute the most important mode of communication in areas where railways have not developed much and form the basic infra-structure for the development and economic growth of the country. The benefits from the investment in road sector are indirect, long-term and not immediately visible. Roads are important assets for any nation. However, merely creating these assets is not enough, it has to be planned carefully and a pavement which is not designed properly deteriorates fast. India is a large country having huge resource of materials. If these local materials are used properly, the cost of construction can be reduced. There are various type of pavements which differ in their suitability in different environments. Each type of pavement has its own merits and demerits. Despite a large number of seminars and conference, still in India, 98% roads are having flexible pavements.

A lot of research has been made on use of Waste materials but the role of these materials is still limited. So there is need to take a holistic approach and mark the areas where these are most suitable.

Pavement or Road is an open, generally public way for the passage of vehicles, people, and animals.

Pavement is finished with a hard smooth surface. It helped make them durable and able to withstand traffic and the environment. They have a life span of between 20 – 30 years.

Road pavements deteriorate over time due to-

The impact of traffic, particularly heavy vehicles.  Environmental factors such as weather, pollution.

PURPOSE Many people rely on paved roads to move themselves and their products rapidly and reliably.

FUNCTIONS  One of the primary functions is load distribution. It can be characterized by the tire loads, tire configurations, repetition of loads, and distribution of traffic across the pavement, and vehicle speed.  Pavement material and geometric design can affect quick and efficient drainage. These eliminating moisture problems such as mud and pounding (puddles). Drainage system consists of:  Surface drainage: Removing all water present on the pavement surface, sloping, chambers, and kerbs.  Subsurface drainage: Removing water that seep into or is contained in the underlying subgrade.

FLEXIBLE PAVEMENTS

Bitumen has been widely used in the construction of flexible pavements for a long time. This is the most convenient and simple type of construction. The cost of construction of single lane bituminous pavement varies from 20 to 30 lakhs per km in plain areas. In some applications, however, the performance of conventional bitumen may not be considered satisfactory because of the following reasons

In summer season, due to high temperature, bitumen becomes soft resulting in bleeding, rutting and segregation finally leading to failure of pavement.

In winter season, due to low temperature, the bitumen becomes brittle resulting in cracking, ravelling and unevenness which makes the pavement unsuitable for use.  In rainy season, water enters the pavement resulting into pot holes and sometimes total removal of bituminous layer.  In hilly areas, due to sub-zero temperature, the freeze thaw and heave cycle takes place. Due to freezing and melting of ice in bituminous voids, volume expansion and contraction occur. This leads to pavements failure.  The cost of bitumen has been rising continuously. In near future, there will be scarcity of bitumen and it will be impossible to procure bitumen at very high costs.

RIGID PAVEMENTS

Rigid pavements, though costly in initial investment, are cheap in long run because of low maintenance costs. There are various merits in the use of Rigid pavements (Concrete pavements) are summarized below:

Bitumen is derived from petroleum crude, which is in short supply globally and the price of which has been rising steeply. India imports nearly 70% of the petroleum crude. The demand for bitumen in the coming years is likely to grow steeply, far outstripping the availability. Hence it will be in India's interest to explore alternative binders. Cement is available in sufficient quantity in India, and its availability in the future is also assured. Thus cement concrete roads should be the obvious choice in future road programmes.  Besides the easy available of cement, concrete roads have a long life and are practically maintenance-free.  Another major advantage of concrete roads is the savings in fuel by commercial vehicles to an extent of 14-20%. The fuel savings themselves can support a large programme of concreting.  Cement concrete roads save a substantial quantity of stone aggregates and this factor must be considered when a choice pavements is made,  Concrete roads can withstand extreme weather conditions – wide ranging temperatures, heavy rainfall and water logging.  Though cement concrete roads may cost slightly more than a flexible pavement initially, they are economical when whole-life-costing is considered.  Reduction in the cost of concrete pavements can be brought about by developing semiself-compacting concrete techniques and the use of closely spaced thin joints. R&D efforts should be initiated in this area.