Design and construction of highway (flexible pavement

constrction of road

1. Design and construction of road (flexible pavement) Presented by- Sadanand Singh Pramod Singh Suraj Kumar vishwakarma Pamkaj verma Daljeet Singh

2. Content Introduction Project road description Material use in construction Thickness design Steps in construction of road

3. Introduction A highway pavement is a structure consisting of superimposed layers of processed materials above the natural soil sub-grade, whose primary function is to distribute the applied vehicle loads to the sub-grade. The pavement structure should be able to provide a surface of acceptable riding quality, adequate skid resistance, favorable light reflecting characteristics, and low noise pollution. The ultimate aim is to ensure that the transmitted stresses due to wheel load are sufficiently reduced, so that they will not exceed bearing capacity of the subgrade . Two types of pavements are generally recognized as serving this purpose, namely flexible pavements and rigid pavements. This chapter gives an overview of pavement types, layers, and their functions, and pavement failures. Improper design of pavements leads to early failure of pavements affecting the riding quality.

4. Project road description Terrain Road alignment Land use Right of way Road cross section & pavement Drainage system Environmental feature Function and intersection

5. Material use in construction Aggregate Asphalt and Bitumen Asphalt Cement Asphalt Concrete

6. Tests of materials Aggregate test Crushing test Abrasion test Impact test Soundness test Specific gravity and water absorption test Bitumen adhesion test

7. Bituminous test 1.  Bitumen Content  2.  Ductility Of Bitumen 3.  Penetration of Bitumen 4.  Specific Gravity of Bitumen 5.  Softening Point Of Bitumen 6.  Flash And Fire Point Of Bitumen

8. Thickness design Several procedures can be used to calculate the thickness of the proposed asphalt pavement. All are based on volume and weight of the traffic that will use the facility and on the load supporting capability of the underlying soil. The AASHTO Road Test and other studies have indicated that heavy-vehicle wheel loads cause much greater damage to roads than do light loads. Thus, where large volumes of traffic with heavily loaded trucks are anticipated, an in-depth analysis of the pavement thickness is important. Because all of the higher functional classifications have the potential for heavy loadings, a traffic analysis is an important part of the preparation for thickness computations. Similarly, a knowledge of the load-bearing capability of the soil is an important aspect of the structural design process .

9. Steps in construction of road Preparation of road layer by layer . Bituminous Surface (Wearing Course).  Base Course.   Subbase . Frost Protection Layer.   Subgrade

10. Typical layers of a exible pavement Seal Coat Tack Coat Prime Coat Surface course Binder course Base course Sub-Base course Sub-grade