How The New Generation Road Is Made Up Of?

What makes up a road?

The construction process is more complex than you might think

It is believed that the first roads paved with bricks were created in the Indus Valley more than 5,000 years ago. Today, there are plenty of roads on Earth to circle the planet over 600 times, but bricks are no longer the material of preference when constructing new roads.

In fact, the roads of today are built using layers of many different materials. Vehicles are heavy – a typical family car weighs well over a ton – which indicates that roads have to be tough enough to withstand the pressures involved. That’s why the load is spread over four layers. At the bottom is the sub-grade – this is the local soil that is compressed with a roller. Next, you have the sub-base, typically made from crushed concrete. The base comes next – another layer of finely crushed rock mixed with asphalt and slag, which is a waste product from steel production. Then comes the smelly stuff – the binder and surface materials, collectively called tarmacadam. The ‘tar’ is the hot, sticky black substance, and ‘macadam’ is the gravel that is densely packed into the tar using a roller. Once it has cooled down, the road is complete.

Rolling along the open road

We only see the dark surface, but roads are layer cakes of rock and tar

1 Markings

Once the layers have been tightly compressed and cooled, paint is used to apply markings.

2 Base layer

This layer of finely crushed rock contains a waste product of steel production called slag.

3 Asphalt

This is actually two materials mixed together: tar, bitumen or pitch, mixed with gravel.

4 Sub-base

The crushed concrete used in this layer is usually recycled material collected from a demolition site.

5 Sub-grade

The exposed soil is compacted by repeatedly driving over it with a roller.