The process paving signifies to covering the areas of the road or ground with a hard, flat surface with the pieces of a concrete slab or other withstanding load and friction resisting material.
A road surface or pavement should have a durable surface prepared from material laid down on areas intended to sustain vehicular or traffic of pedestrians. The earlier paving material used were gravel road surfaces, cobblestone and granite setts. But these surfaces have mostly been replaced by concrete laid on a compacted base curing to produce an extensive hard surface to withstand high static as well as dynamic traffic loads.
Road surfaces are systematically earmarked to guide traffic flow. Nowadays, permeable paving methods are being applied to create low-impact roadways and pedestrian’s walkways. Pavements are crucial to countries that depend heavily on road transport such as the US and Canada. Therefore, research studies have been worked out to obtain suitable paving material to achieve Long-Term Pavement Performance. This was also done to optimize the life-cycle of different road surfaces of different materials including concrete.
A concrete slab is used as a common structural material of modern buildings. Horizontal slabs of steel reinforced concrete, R.C.C. of thickness ranging between 4 and 20 inches ie. Thinner slabs are also seldom used for the exterior of the housing complex paving. This concrete paving was found to possess satisfactory performance to withstand traffic loads.
To construct paving concrete surface, Portland cement concrete is used generally. Portland cement concrete is produced by using a concrete mix of Portland cement, coarse aggregate, sand, and water in a stringent proportion. The composition of all modern mixes uses various other ingredients to increase strength, workability, with the addition of a reduced amount of water. This is done to avoid, and to mitigate harmful, unwanted chemical reactions and for other beneficial properties in the concrete to be used for paving slab. In many concrete mix fly cases, ash is also added. This is found to obtain concrete with good paving characteristics. This reduces the cost of the concrete and improves its physical properties remarkably.
The concrete material thus formed is applied in the form of a freshly mixed slurry and worked mechanically for the compact interior of the paving work and force some of the cement slurries to the surface of the paving to produce a smooth, dense surface free from honeycomb pattern in the paving surface. The water added in the mix to combine a molecular level in a chemical reaction taking place in the concrete paving slab, called “hydration”.
Pros And Cons Of The Concrete Paving Slab
Major advantages of the concrete paving slabs are that its typically stronger and durable than asphalt made roadways. Concrete paving can also be grooved to result in a durable skid-resistant road surface. The major disadvantage in concrete paving is its higher initial cost and takes more time in curing and finishing to produce concrete paving. However, this cost offset is due to the long lifespan of the pavement.
Concrete pavement can be maintained conveniently utilizing a series of methods called concrete pavement restoration technique. This methodology comprises the following operations:
- Diamond Grinding
- Dowel Bar Retrofits
- Joint And Crack Sealing
Diamond grinding is also beneficial in noise abatement and in restoring the property of skid resistance in the older concrete pavement.
Some patch repair work asphalt is found to be applied on concrete pavement. Combination of Portland cement concrete sublayer with an asphalt layer is sometimes done. They are commonly used to rehabilitate existing roadways rather than in new construction.
The disadvantage of such asphalt application is due to the movement in the joints between the underlying concrete slabs, due to thermal expansion and contraction, or from deflection of the concrete slabs axle loads caused by trucks, usually causes cracking in the asphalt. This causes severe damage and is not recommended.
Concrete paving slab construction is an advanced technology used for road construction. Although it is costlier than conventional road material, its long life makes it cost effective.