Skip to main content

Major Pisa link gets upgrade

Recycling with foamed bitumen is being used for lane reconstruction on the SP11 road in Italy, where contractor F.lli Lepri is carrying out work on a 14km section. The SP11 is an important link forming part of the Colline per Legoli Highway connecting the SS67 Tosco-Romagnola Highway near Pontedera with the southeast region of Pisa Province up to the borders of Florence Province.
February 29, 2012 Read time: 3 mins
Recycling with foamed bitumen is being used for lane reconstruction on the SP11 road in Italy, where contractor F.lli Lepri is carrying out work on a 14km section.

The SP11 is an important link forming part of the Colline per Legoli Highway connecting the SS67 Tosco-Romagnola Highway near Pontedera with the southeast region of Pisa Province up to the borders of Florence Province.

The contractor is using a technique that meets Italian standards to client Pisa Province’s specification. The aim of the work is to improve the surface quality by repairing damage to the existing road.

Cold recycling has been used with foamed bitumen on sections with clearly identifiable damage and cracks in the surface, to produce a road surface 200mm thick. This features an 80mm asphalt binder layer and a 40mm asphalt wearing course. Cold recycling has been used to a depth of 100mm on those sections with less damage.

The cold planer makes an additional pass while any additional material, additives and foamed bitumen is sprayed into the mixing drum. Micro-processor controls ensure optimum metering of the sprayed additive when mixing with the pulverised material.

The processed material laid behind the machine is pre-compacted by a heavy screed and is followed by profiling with a grader and further compaction. By adding foamed bitumen, mixed material made from different natural additives or asphalt granulates can be turned into high-quality roads.

172 Bomag has developed the MPH125 recycling unit in collaboration with contractors and says that the machine is efficient and reliable and offers high performance for mixing lime, fly ash and cement for soil stabilisation. For cold planing, the unit can be used in multiple applications to pulverise old and damaged roads to stabilise the road.

The speed of the rotor is adjustable to match the job while the mixing drum adapts automatically to milling depth, the type of soil and materials used. Binder and soil can be processed to form a uniform mix with minimal wear and optimised energy consumption.

A high quality mix is created from the recycled materials when combined with water and binding agents and the new asphalt binder layer features good mechanical properties while the road's bearing capacity is improved, so there is no need to use reinforced structures. The uniform single-layer binder courses contain no weak points and there is less stress on the sub-base.

A recycling train can work in a single lane so that reconstruction can be carried out on half the carriageway and the entire road can be opened up again for traffic at the end of the shift.

A BOMAG Terrameter can carry out tests during cold recycling while work is ongoing. This unit automatically tests the bearing capacity of the asphalt layer during compaction, after which dynamic plate tests are applied.

Cold recycling can offer fast road repairs and as long as processes are adhered to, the technique offers a road repair with good mechanical properties and a long projected working life.

For more information on companies in this article

Related Content

  • Advances in road milling technology
    June 4, 2019
    New systems developed for the road milling machine market will boost safety and efficiency
  • Manufacturers have developed key innovations in recycling machines
    March 4, 2015
    Manufacturers are making advances in stabiliser/reclaimers and milling machines - Mike Woof reports. The market for milling equipment is a competitive one, with a range of companies from around the globe now offering machines for this segment: BOMAG, Caterpillar, Dynapac, Roadtec, Volvo CE and Wirtgen. In recent years a number of Chinese firms have entered this segment and determining the number of machines these companies manufacture is difficult, although most of their units are sold in China. But interna
  • Innovative road construction
    February 19, 2024
    Wirtgen is introducing an innovative concept for road construction in the shape of its new WRC 240(i) rock crusher. The machine has been developed from the firm’s proven soil stabiliser technology and is designed to break coarse rocks in-situ, as found in hand-packed pavement layers.
  • Cost-saving compact twin layer asphalt paving
    February 28, 2012
    Twin-layer paving offers high quality, long lasting road surfaces to be constructed. Paver manufacturer Dynapac is one of the pioneers of the twin-layer paving technique, which it calls Compactasphalt. According to Dynapac this method offers major benefits to contractors and clients alike as roads surfaced using this technique last longer and are cheaper to maintain. To ensure contractors have maximum utilisation of their machines, Dynapac offers a modular paver system that can be operated using the convent