When we talk about Asphalt Surfacing, we used to generally be talking about the use of Stone Mastic Asphalt (SMA) or Hot Rolled Asphalt (HRA). These materials are often used on roads, with the SMA becoming the preferred material for the Highways Agency because of the reduced noise levels produced by traffic.
However, through more European alignment, Macadams and Asphalts have been brought under one umbrella term; Asphalt Concrete. So, for example, what used to be known as a 20mm Dense Bituminous Macadam (DBM) is now termed an AC20 (Asphalt Concrete in 20mm).
SMA and HRA are almost always used as a Surface Course layer of the construction, but materials such as an AC20 are used beneath the surface course so now we talk about Asphalt forming more than just the surface course layer because of this European alignment which brings in Macadams.
In terms of construction, once the Groundworks, or sub-base, are completed the base, binder and surface course are constructed, depending on the client’s specification and the use of the road or other areas.
Terms such as Asphalt, Macadam, Tarmac, Bituminous Macadam and Bitmac may be used loosely both within and outside of the construction industry, so it is important to be sure what your requirements are. We can help and are more than happy to consult on whatever project you are working on.
You should also note that Americans use the term Asphalt to refer to a substance that we in the UK and Europe call Bitumen. Bitumen is a thick and sticky by-product of the fractional distillation of crude oil which is used to bind aggregate and minerals in both Asphalt and Macadams or Tarmac.