A pavement is the surface made specifically for travel. The concrete surface is long-lasting and can withstand the traffic load over it. Pavements allow chafing for ground transportation, therefore providing relaxation during the drive. The traffic load is transferred from the upper surface to the regular soil, down to the lower harder soil and so forth and so on. It is important for pavement constructors to understand this physics.
Previously, even before vehicles became a regular means of transportation, cobblestone paths were purposed for the animal carts and human beings. Today, pavements are mainly designed for vehicles and human beings. When designing a pavement, the drainage system and other environmental conditions feature as great concerns. Roads in the ancient times were constructed using stones or gravel and sand. Water was the main binding agent. It levelled and provided the final look for the surface. Pavements are categorized into two main designs: the flexible and rigid pavement.
The flexible pavement
Flexible pavements are the kind of pavements that mirror the deformation of either the sub grade or subsequent deposits of the surface. A tarmacked pavement does not need reinforcement when laying. It is laid with a fabric specialized to allow limited flow and/or shifting of the roadbed under-ground alterations.
Flexible pavement design is founded on the load dispensing specifics of the constituent layers. The top of the tarmac pavement is inclusive of water and it is gravel bound. This type of pavement has little or no strength in terms of structural action. The layers transfer the compressed stresses on to the bottom layers using grain transfer. This is done with the help of the granular structure’s contact points.
The compressed stress majors on the surface of the pavement which is directly beneath the load of the wheel. It is equal to the pressure caused by the contact that is below the wheels. The fact that it can dispense the stress to a vast area, it also makes sure that the stress decreases in the layers beneath it. This design can have a number of layers but the top one has to be the sturdiest with the highest compressed stresses. Since the lower layers are not prone to wear and tear as they receive decreased stress, they can be constructed using inferior materials.
The rigid pavement
The word rigid speaks for the strength and rigidity of this type of design. Unlike in the flexible design where the load is fully on the area of the wheels, this design distributes the load over a wider area of the sub-grade topsoil. The strength and the rigidity come from the slabs that are laid with reinforcement from steel. This type of pavement is made using cement concrete. The cement concrete can be reinforced, plan or pre-stressed. Before the plan is set in motion for the construction of the rigid pavement, it is designed then analysed using the supple theory.
All types of engineering have their merits and demerits. The two designs have clearly shown that one maybe picked instead of the other based on the specifics of a particular project.