Concrete for Traffic Areas

Concrete for Traffic Areas

Concrete for traffic areas has many applications and is often installed as an alternative to blacktop because of its durability and other advantages.

The uses of concrete for traffic areas:

·     Conventional road building

·     Concrete roundabouts

·     Runways

·     Industrial floors

When concrete is used for these applications, the concrete layer acts as both a load bearing and a wearing course. To meet the requirements for both courses, the concrete must have the following properties:

·     High flexural strength

·     Freeze/thaw resistance

·     Good skid resistance

·     Low abrasion

The composition is a vital factor in achieving the desired requirements. The criteria for selection of the various constituents are as follows:

·     Aggregate

-       Use of low fines mixes

-       Use of a balanced particle size distribution curve

-       Crushed or partly crushed aggregate increases the skid resistance and flexural strength

·     Cement

-       Dosage 300–350 kg/m³, usually CEM I 42.5

·     Additives

-       Silica fume for use in heavily traffic areas or to increase the durability generally

-       Increase in the skid resistance by spreading silicon carbide or chippings into the surface

Concrete for traffic areas is a special concrete and the following points require special attention:

-       Large areas are often installed using paving machines. The consistence must be suitable for the type of machine

-       Improvement in skid resistance by cut grooves or brush finishing

-       Thorough curing is essential