What is HFST?
High Friction Surface Treatments or HFST are also known as anti-skid surfaces. These are road surface treatment systems that are composed of “tough” polish-resistant, abrasion-resistant aggregates bonded to the pavement surface using a resin.
The Australian Road Research Board says “Used appropriately, they (HFST) can help stop vehicles from skidding on or off roads, and increase a vehicle’s ability to brake more effectively at critical times” and that “…known accident blackspots, approaches to intersections and pedestrian crossings, and tricky-to-negotiate corners can all benefit from proper use of High Friction Surface Treatments” (ARRB, 30 August 2018).
In Australia, Crash Reduction Factors for calcined bauxite surfaces like OmniGrip HF ranges from 40% for all casualty crashes, to 50% for wet weather crashes. However, Australian and international studies have achieved much higher reductions when HFST was used to address specific crash issues, in some cases obtaining up to a 100% reduction in crashes.
What sort of ‘Aggregates’ are used?
Aggregates are critical to the skid-resistance of the Antiskid High Friction Road Surface system. The surface of the aggregate provides the micro-texture, which directly affects the skid resistance. Two of the key properties of aggregates used are polish resistance (generally reported in terms of polished stone value or PSV) and abrasion resistance (aggregate abrasion value or AAV).
The PSV is a measure of how resistant an aggregate is to polishing under traffic wear. The higher the PSV, the better the aggregate can keep its surface texture (micro-texture). AAV is a measure of how resistant the aggregate is to material loss under traffic. Aggregates used by Antiskid are generally calcined bauxite of 3mm nominal maximum size.
What is Calcined Bauxite and why is it used?
Calcined Bauxite is obtained by calcining (heating) superior grade Bauxite at high temperature which removes moisture thereby increasing the alumina content.
The characteristics of Calcined Bauxite such as the high alumina content, low iron, grain hardness, toughness, thermal stability and high mechanical strength make it the ideal choice for resin-based systems which must be resistant to skidding and abrasion forces.
OmniGrip HF uses a proven resin binder to hold high-PSV calcined bauxite in position so that it doesn’t become embedded or displaced under the heaviest of braking. With its high PSV, calcined-bauxite resists polishing, ensuring it maintains its micro-texture for longer than other road surfaces.
Vehicle tyres adhere to the micro-texture of the calcined bauxite, providing better grip on bends and curves or when braking hard, enabling the driver or rider to maintain control. The vehicle is more likely to stay within its lane, reducing the risk of losing control and leaving the road to hit a barrier, roadside object or another vehicle.
Used at intersection, vehicles can stop in a shorter-distance, reducing the likeihood of a crash and reducing impact speeds should one occur.
OmniGrip HF is resistant to road contaminants including oil, petrol and de-icing salts. It has excellent adhesion to asphalt and concrete surfaces so it can be used on all sealed roads and driveways.
The installation process
As stated above, the Omnigrip HF application consists of calcined bauxite aggregate held by a specialised epoxy modified resin binder and this ensures high-tyre forces will not remove the aggregate.
The application process has been developed and finetuned over many years so that Antiskid can be sure of delivering world’s best practice applications for our client base.
Prior to any application of Omnigrip HF the surface substrate is thoroughly cleaned of all grime and oils to maximise adhesion. This is accomplished using a variety of methods.
Following the cleaning our highly experienced applicators apply the Omnigrip high friction road surface resin which is laid over an existing substrate.
Once the resin is applied it’s then followed by the application of the calcined bauxite. This is generally accomplished via hand seeding to ensure consistency of application.
The surface is then left to cure for approximately 4 hours.
The final stage is for a mechanical sweep of the surface to recapture excess aggregate and to provide a stable surface. At this stage the surface is once again trafficable for normal use.
Proven Process, Improved Safety
There is no doubt about the overall value of specifying Antiskid Omnigrip HF surfacing. It is an established proven process for saving lives and ensuring the highest level of skid resistance onto any road surface.
In fact, in August 2018 transport research organisation for Australian Road Research Board (ARRB) released guidelines on the use of high friction surface treatments to help reduce the road toll by making roads more skid resistant, especially at known black spots and pedestrian crossings.
The guide highlights international experience on HFST, citing a survey of HFST in the UK issued by the Association of Directors of Environment, Economy, Planning and Transport, which suggested the average design life of a HFST was between eight and 12 years.
The report is available for download at the bottom of this page.
Antiskid is proud to have been commissioned, over many years, by most of the Metropolitan Local Councils and Perth Main Roads Department to install the Omnigrip high friction road surface treatment at numerous locations. These locations include intersection, school crossings, roundabouts and black spot locations to name a few.
- Hi Friction # SRV > 70
- Increased Surface Texture
- Up to 33% Reduction in Vehicle Braking Distances
- Reduced Threshold Braking Speeds
- Fuel & Oil Resistant
- Accident Reduction
- Concrete/Asphalt Surface
Recommended Application Sites
- School and Pedestrian Crossings
- Intersections and Roundabouts
- Tight Radius Corners and Slip Lanes
- Steep Inclines / Declines
- Black Spot Locations
Antiskid – the specialist high friction road installer
Antiskid Industries is the preferred supplier and installer of Omnigrip HF in Western Australia. We have gained this prestigious recognition as a result of our highly experienced and well-trained operators. We have specialist plant and equipment that is available at short notice, we are fully equipped and able to have everything on-site to facilitate a seamless installation. As a consequence of this, time on the project is generally reduced with little or no disruption and traffic congestion.
We would love to hear from you, so please message us through our Contact Us form on this page or telephone for an obligation free meeting to discuss your requirements.