New developments are pushing the pace of progress in asphalt paving

New developments will broaden the asphalt paving market - Mike Woof reports

A new approach to materials could help address rising bitumen costs. Increased use of recycled asphalt pavement (RAP) in road construction can cut a major chunk from paving costs, with an array of technologies now available. In the US, RAP is one of the most widely recycled materials and current techniques allow roads built with this material to perform well for all traffic conditions. Some European countries are also making widespread use of RAP, although others have yet to see the benefits.

But another alternative option is now being made more widely available, with lignite producers increasing their market presence. A subsidiary of German producer 3994 RWE, Rheinbraun Benelux, is raising its profile in Europe with regard to its lignite-based alternative to bitumen for use in road construction. At present the firm is active in Belgium, the Netherlands, Luxembourg and the UK, but may well look to expand its operations. And with bitumen prices increasing and concerns over long term availability, a lignite-based bitumen derivative may well prove a suitable source for the road construction industry.

Meanwhile in the UK, 2399 Tarmac Pavement Solutions is offering a service to customers intended to address issues over rising material costs. This new business unit within its National Contracting business segment, will produce and supply cement-bound and recycled materials. In Europe bitumen prices have climbed fast in recent years and in the UK for example, these have increased 60% in just two years. Offering materials using cement-bound or recycled asphalt will help contractors, local authorities and network operators cut the cost of new build road construction projects.

An alternative option to bitumen-based materials, cement-bound pavements consist of a hydraulic-bound mixture used as the base layer, predominantly a cement-bound granular material, which is then surfaced with conventional asphalt.

Cement-bound roads can be designed to give equivalent service life performance to both conventional asphalt and rigid concrete pavements. Removing the need to use high volumes of bitumen can also deliver significant financial savings.

Tarmac Pavement Solutions is also supplying Tarmac’s proven FoamMaster system, a road surfacing process which uses road arisings in cold-mix production to create an energy-efficient alternative to traditional hot asphalt. Another material offered is TarmacDry, a porous asphalt system which manages surface water by allowing it to pass through its structure into a granular reservoir layer.

According to Tarmac, bitumen accounts for a substantial portion of the cost of building a new road. This price volatility means that construction should look to cement-bound materials and recycled asphalt to reduce reliance on bitumen.

In addition, the Mastic Asphalt Council (MAC) has unveiled its novel low-melt mastic asphalt that cuts working temperatures by up to 13% and offers significant energy savings. A key feature is the use of an advanced binder, the result of extensive research in Germany and the UK. It is designed to increase the workability of the mastic asphalt at lower temperatures, with no loss in performance or durability. By lowering working temperatures by up to 35°C, the new low-melt solution requires significantly less energy to apply. The material is suited to use in applications where waterproofing is required, including bridge decks and car park surfaces.