Winton Shire Council

GSB-88 TrialWinton-Jundah Road

2015/16

About Winton ShireWinton Shire, in central western Queensland

covers over 62,000 square kilometres and is home to a rich history and beautiful

landscapes.

Located 1,500km north-east from Brisbane the shire is home to over 1,400 residents who live in Winton, surrounding stations or the townships of Corfield, Opalton and Middleton.

The region is the inspiration behind A. B. ‘Banjo’ Patterson’s ‘Waltzing Matilda’ and is also the birthplace of QANTAS.

More recently Winton has become famous as the Dinosaur Capital of Australia and home to the world renowned Australian Age of Dinosaurs – a premier tourist attraction situated just outside of town atop a mesa with spectacular views.

Winton hosts a large selection of Cultural activities such as the Outback Festival, a five day celebration of everything ‘outback’ and the Vision Splendid Outback Film Festival promoting Australian film making and showcasing Western Queensland as a setting for production.

WeatherSummer in Winton is predominantly hot with temperatures routinely exceed 40ºc from October to March and the Shire recives the majority of its average rainfall (just over

400mm) during this time.

Road NetworkAt 62,000 square kilomters in size Winton Shire has just over 2,500km of road network. While shire roads are predominantly gravel the Council has managed to increase the size of its sealed network from just over 14km in 2005 to 60km in 2015 thanks largely to federal asistance grants or other sources of non-shire revenue.

Winton - Jundah RoadAll of these sealing projects are on the Winton-Jundah Road between the town of Winton and Lark Quarry (home of the Dinosaur Stampede) - a link vital for regional tourism. Seal works focused on two sections - joining the ‘gaps’ in the first 45km of road and then providing a series of overtaking opportunities over the next 65km to Lark Quarry.

Performance of rural seals

Many of Wintons rural sealed roads have the same characteristics - pavement constructed of local material, a C170 seal with 14mm precoated aggreagate followed up with a polymer modifed bitumen (PMB) reseal using 10mm aggregate.

Annual average daily traffic (AADT) counts tend to be only a couple of hundred per day and on the Winton-Jundah road and, as with many Western Queensland roads, a high proportion of the axle hits are from triple road trains.

As seals approach intervention they look similar to the examples below - oxidised bitumen start to release stone and lead to small pock marks that require patching. Increased pacthing and maintenance costs are indicators for treatment however typically the stone is in good condtion and it is only the binder that is failing.

Seal is generally in good condition (high % stone coverage and rough appearance) but is let down by the oxidized binder simply letting go of stone.

As more and more stone is lost the seal takes on a pocked appearance that requires a lot of manual patching to ensure potholes wont form.

This seal has been patched, by hand, with emulsion and 7mm aggregate.

After eight years this section of road is due for treatment.

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The Predicament

Over the period of 2005 to 2015 Winton Shire was successful in recieving grants to upgrade the link to Lark Quarry, indeed the length of sealed road went from 14km in 2004 to just over 60km today (2015).

These projects focused on sealing the first 45km (to the top of ‘the jumpup’ pictured left) as well as a series of 4km to 8km long overtaking opporunities.

While these works increased the trafficability and safety of the road it would also be a double edged sword with Council needing to dramatically increase its reseal budget and somehow manage spikes in 2019 and 2024.

In 2014’15 financial year the network required 8km of reseal at an expected cost of $400,000 however due to financial restraints Council could only afford a budget of $200,000. Council engineers were faced with two options :-

1. Reseal half the area for $200,000, or;2. Seek an alternative to a PMB 10mm reseal and treat all 8km

Resealing less area might aleviate budget constraints for one or two years but was not a viable options when considering the 15 to 20 year program.

Reseal Program - The spike in 2019 could be spread out over three years (2018 to 2020) but this would still be double what Council has historically budgeted for reseals.

A Case for GSB-88

Council engineering staff were invited to a demonstration of GSB-88 in Barcaldine in mid 2014. The ring road at the recreational oval was treated with a variety of spray rates ranging from 0.6L/m2 up to 1.0L/m2

with an application rate of 0.7L/m2 being most appriorate for 14mm aggregate.

GSB-88 rejuvenates asphalt pavements by reintroducing oils and resins lost to UV rays, oxidization, temperature swings and precipitation. These environmental factors accelerate the raveling process on untreated pavement causing significant damage over time.

Whilst a typical PMB reseal cost up to $7/m2 (jobs 50km to 100km out of town) the GSB-88 treatment was less than $2/m2.

As a low cost alternative to a chip reseal, GSB-88 allows Council flexibility in its reseal program, allowing Council to flatten the spikes in individual years. More appealing is the potential for GSB-88 to completely replace traditional chip reseals - particularly on urban roads where there are now layer upon layer of stone and bitumen.

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Annual treatment cost

PMB Reseals

GBS88 + PMB (5 yr)

GSB88 (every 5 years)

Impact on reseal projections

GSB-88, as a low cost treatment, gives Council flexibility in its reseal program - allowing Council to push back reseals during peak years and smooth out the program.

The potential to reapply GSB-88 in lieu of a reseal gives further cost savings.

It is expected that all town streets not requiring pavement reconstruction will be rejuvenated in the future.

Winton Shire Council GSB-88 Trial

In late March 2015 Winton Council conducted the first full service GSB-88 trial in central Queensland. Two 4 kilometer sections of the Winton-Jundah Road were identified, patched and swept prior to spraying.

Day one was set aside to try various application rates which were allowed to completely cure overnight before deciding the most appropriate rate for the 14mm seal. For the first run the crown was sprayed at a rate of 0.5L/m2 and then the sides with a rate of 0.6L/m2. This gave the crown (where the most pitting and stripping had occured) a heavier rate.

20 minute break time

After a period of 20 to 30 mintues the GSB-88 breaks and turns from brown to black and can be opened to traffic.

Incidently GSB-88 was easily washed off the guidepost using an aerosol solvent.

Visual Appearance

GSB-88 has a very rich fatty appearence after it has been sprayed. Even as light as 0.6L/m2 the product easily fills the voids and penetrates the old seal.

Weeks after being sprayed GSB-88 has a very wet look despite being dry to touch and trafficable to all vehicles.

Gilsonite

Gilsonite is a natural form of asphalt found in the Uintah Basin. Because gilsonite does not undergo the oil refining process, it is naturally better for the environment, extending the

life of pavement with its unique chemistry.

3 months later...

After 3 months (the middle of winter) the GSB-88 still has a very black, high contrast appearance. On closer inspection micro bubbles of bitumen are forming (despite the colder months) indicating the GSB-88 is starting to enliven the bitumen.

6 months later...

After 6 months (start of summer) the GSB-88 remains very dark and visually distinctive. Small bubbles of bitumen are starting to form indicating the chemical process is well underway despite the previous cooler months.

9 months later...

After nine months (the middle of summer) the GSB-88 has completely revived and enriched the underlying bitumens seal with large bubbles of C170 coming through. As the GSB-88 is only a thin layer bleeding is not expected to be a problem.

Winton Shire Council

75 Vindex StPO Box 288Winton QLD 4735

www.winton.qld.gov.auwww.experiencewinton.com.au www.rnrbitumen.com.au

www.roadsandconcrete.com

www.asphaltsystemsinc.com