For many people the words 'tarmac' and 'asphalt' are used interchangeably, but in fact there are some quite important differences between them. When it comes to paving different types of areas, it can be valuable to know the following differences. Such differences include make up, use and advantages, to name a few.
So let's start off with tarmac, then move onto asphalt.
Tarmac is made from tar poured over crushed stone, built up in four layers. The type of stone used depends on location, but the important characteristic property of the stone used in making tarmac is that it is of high strength.
Because the entire surface of the paved area is filled with crushed stones, and those stones are very difficult to crush, it means tarmac can be more expensive than asphalt. That doesn't mean, however, that asphalt is always the most economical choice. The answer to which is most economical, as it so often tends to be, is that it depends.
When government authorities and tarmac contractors are planning major roads, they will usually place asphalt for the majority of the road building, and use tarmac in those sections where more traction is desirable.
Interestingly, though, tarmac is economical when the area to be paved is not large and the job will be quick. Speaking of quick, it's important to know there are different types of tarmac that can be used. The ones that matter in terms of speed are quick curing tarmac and slow curing tarmac. How they differ is that slow curing tarmac has chemical solvents (called "cutback agents") added to keep it workable at lower temperatures. This is what is most often used on small paving jobs. The costs are lower, but because of the cutback, the tarmac takes longer to harden and remains sticky for longer.
On the other hand, quick curing tarmac is normally used on larger surface areas where a machine can be deployed to lay the tarmac, which is faster than laying it by hand. This also allows it to be heat blasted by the machine to keep it workable without needing to add much cutback or even any at all.
The main advantages of tarmac include good traction, ability to support heavy loads, and durability in all weather conditions.
Asphalt uses much less aggregate material than tarmac, but requires more machinery and manpower to lay it down. This means asphalt is very economical for covering large areas.
Asphalt's lower aggregate composition, however, means it is more susceptible to weather damage and more easily corroded by oil products. Fortunately, it's also easier to maintain and repair than tarmac. For example, pot holes can simply be filled in with a new batch of asphalt, costing next-to-nothing to produce in the required quantity for this purpose.
One of the best advantages of asphalt is that it gives a smooth and quiet riding surface. Snow also melts faster on asphalt than it does on tarmac.
Asphalt is also considered to be a more environmentally friendly choice than tarmac because it doesn't require quarrying huge quantities of stone, and it is 100 percent recyclable. Asphalt can be recycled on the spot, using chunks of old asphalt to create filler for potholes.
The material can be resurfaced periodically, thus increasing its lifespan, adding strength reinforcement, and restoring the original smooth surface.