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Road surfacing is the process of applying a durable material on the surface of an unpaved road or walkway for the purpose of sustaining vehicular or foot traffic. In the past the surface materials were gravel, cobblestones and granites, but these have been replaced by asphalt or concrete on a prepared, compacted ground base. There are paving methods that are in application today which are employed to practically all kinds of walkways. Check out tarmac drives Lichfield at this link to get started.

Asphalts are normally laid on a gravel base, wherein the thickness of the base is the basis of the thickness of how much asphalt must be poured in to form a layer over it. This flexible pavement has a binder called bitumen which allows the asphalt to sustain plastic deformation resulting from the effect of fatigue due to repeated loading over time. Asphalt surfacing is recommended for high volume primary highways where the rate of traffic closes at 1,200 vehicles per day. The advantages of using asphalt surface are relatively low cost infrastructure investment, a low noise effect when driving through the asphalt-paved road, and the ease of repair. The disadvantages are less tensile strength than concrete so it becomes less durable, tendency to soften during hot weather and contains a certain hydrocarbon compound which can be pollutant to the ground. In the early 1960s, rubberized asphalt was introduced and which was composed of a mixture of broken particles of used rubber tires and asphalt. While its application has given some form of durability, not all walkways can be paved with it due to the fact that this asphalt mixture is temperature-sensitive and can only be useful in spot locations.

Concrete surfacing makes use of a concrete mix of Portland cement, coarse aggregate, sand and water. Otherwise, many mixture innovations have been experimented as admixtures, all for the purpose of increasing the concrete’s workability, requiring lesser amount of water, reducing any harmful chemical reactions. An example is the addition of fly ash which was found to reduce the cost of concrete and improves its physical properties. For more info, read more about tarmac dirveways Tamworth.

Still another form of road surfacing method is the composite pavement process which combines Portland cement concrete, as a sublayer, to an asphalt pavement. This method is often tried in rehabilitating existing roadways rather than reconstructing the road. Asphalts are overlaid over distresses concrete to restore into a smooth road surface. But this method of overlaying does not come with after effects, such as a result of cracks in the asphalt caused by the movement of the joints in the concrete slabs which is a result of thermal expansion and contraction. To solve this condition, the concrete pavement is broken apart first through what they call a break and seat, crack and seat procedure, which is called the rubblization process, before applying asphalt over it.

For more info, go to http://www.ehow.com/how_2099757_design-driveway.html.

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