Build thinner and lighter constructions to a lower cost.

Hyttsten for building material is crushed and sold in the same selection as crushed rock.

Normal section of road

 

When construction begins the topsoil is removed. The free surface, where the road will be built is called sub grade. Different kinds of bearing layers are spread out and this is finished off with a surface course. This surface course can be made up of gravel or asphalt.

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Recommendation for the various layers:

 

Surface course	Asphalt or gravel road - Hyttsten 0/16 or Hyttsten 0/8
Road base	Asphalt, AG, or with gravel road - Hyttsten 0/32
Sub base	Hyttsten 0/63. 0/90, 0/125 or 0/250
Sub ground	Hyttsten 0/63, 0/90, 0/125 or 0/250

What is the purpose of the various layers?

Surface course
As the name suggests this is the top layer. On main roads asphalt is used, while on smaller roads oil-gravel or normal gravel/crushed material can be used. Surface course is replaced or complemented/filled in when required. On gravel roads Hyttsten's ability to bond with mud can be recommended. It is important to get a larger percent finer fraction to get maximal bonding between mud and gravel. This is why we recommend Hyttsten 0/8mm, best affect for stabilizing and bonding of mud.

Hyttsten 0/8mm can also be used successfully for stabilizing muddy top layers etc.

Road base
The road base helps to distribute the load over a larger area on the sub base. It prevents the finer surface course draining into the coarser sub base.

Sub base
The sub base has several functions. Firstly it distributes the load on as much of the sub grade as possible. Furthermore, it is dimensioned to insulate against frost where the risk for frost damage is high. It has a draining property which averts water which also leads to minimizing frost damage.

Ground base
The ground base is sometimes necessary to enable the sub grade to carry machines and cars across e.g. wet soil. It is often used to ensure sufficient insulation for protection from ground frost.

Additionally
The height of the various layers, and the selection of material, varies depending on the needs of the road. The bearing capacity determines the construction, however, sometimes it is insulation against ground frost which is the determiner. Usually there is a mix of requirements. For larger road construction the requirements from "Swedish transport administration" are the determining factor.

Foremost today it is the crushed material, Hyttsten or crushed rock, which is used as road construction material. Natural material i.e. gravel is only used on exception.

Rule of thumb:
Coarser material at the bottom and finer on the top layers.