The Hiway Group has been delivering innovative pavement recycling solutions throughout the country since 1986. Hiway Stabilizers, part of the Hiway Group, is Australasia’s largest provider of specialist pavement design, construction and recycling solutions across the contamination remediation, roading, infrastructure and construction sectors.

Hiway’s commitment to innovation, environmental sustainability and industry leadership has enabled the company to introduce cutting-edge technologies to market and develop its own advanced methodologies and proprietary stabilising products throughout Australasia. Over the past 30 years, Hiway has led the way in the use of stabilisation in construction and infrastructure projects. 

Hiway’s focus on reducing, re-using and recycling construction waste, materials and assets led it to investigate a more recycling-focused means of remediating flushed surfacing layers. Flushed road surfacing is a large problem in Australia and New Zealand, both of which rely heavily on spray or chip seal as a cost-effective wearing course for flexible pavements. 

The purpose of a wearing course is effectively to provide a waterproofing layer to protect the pavement from water ingress, while providing a
skid-resistant medium for vehicle traction. Flushing occurs when defective pavements and/or surfacing sees the bituminous binder migrate to the surface of the seal, filling the voids and, in turn, providing a slick
low-skid-resistance surface, which can be extremely dangerous in wet weather to road users.

Conventional methods of treating flushed surfacing generally involves high-pressure water blasting of the surface, essentially removing the excess binder, often along with the seal’s waterproofing capability. This process also reduces the durability and life of the seal, while also creating a fair amount of waste that needs to be disposed of responsibly, which comes at a reasonable cost. 

Over the past three years, Hiway has worked through an R&D process to develop a new method for the treatment of flushed seals, and the result was Hitex™. HiTex is a patented technology for the treatment of flushed wearing courses. The innovative process allows for the restoration of the macrotexture and skid-resistance properties of the wearing course, through correction of the binder/stone volumetrics within the surfacing layer without removal of any excess bitumen. This ultimately improves the life of the pavement as there is less chance of water ingress through the surfacing layer.

HiTex achieves the volumetric correction through the infrared heating of the existing flushed surfacing layer, followed by supplementation with preselected sealing chip, which is applied to the heated surface at a predetermined rate. The sealing chip is heated in situ and then rolled into the surface to optimise embedment and chip penetration, providing improved macrotexture and skid-resistance performance. The configuration of the HiTex unit allows for selective treatment of the flushed pavement via single- or double-wheel tracks, or, where necessary, full-width treatment. 

Hiway has received strong interest from local and state roading authorities off the back of a number of field trials, where independent evaluation of field performance has shown the HiTex process has successfully increased skid-resistance and texture properties from requiring immediate intervention due to safety concerns, to being well above intervention threshold post treatment. 

The long-term performance of the HiTex process is currently being assessed; however, Hiway feels confident, based upon the results to date, that the process will provide a long-lasting treatment option to asset owners and managers.

For more information, contact Hiway Group on 09 426 3419 or email info@hiways.co.nz. Alternatively, visit www.hiways.co.nz or www.hiways.com.au.

FACT FILE

HiTex™ provides the following benefits:

• No hydrocarbon waste generated, and no landfill dumping or dump sites required.
• Increased pavement life, and reduced defects and future pavement repair due to maintenance of seal integrity.
• No risk of ‘de-waterproofing’ the pavement.
• Optimised treatment – ability to adjust chip source, application and size, depending on site conditions.
• Selective treatment – only treats flushed pavement area.
• Both wheel tracks can be treated simultaneously if required, providing a highly mobile and productive operation.

 APPLICATIONS

• Pre-seal repairs – correction of flushing surfacing prior to re-seal.
• Texture/skid-resistance improvements of flushed surfacing layers.
• Drying of wet pavements.