Morphettville Racecourse Sandtrack Rehabilitation Works AustStab Awards of Excellence 2013 South Australian Jockey Club Innovation or Excellence in Sustainability in pavement stabilisation Sponsored by

Overview Morphettville Sandtrack  Increasingly contaminated with material from the base of the sandtrack.  Source for hoof bruising in the race horses Prone to saturation  Inadequate drainage  Subsurface drainage Water-proof the sandtrack to allow year round operation without soft clay contamination from the subgrade. Potentially expensive risks that needed a solution and not just treatment. Objectives Eliminate material contamination from the base of the sandtrack into the both the sand of the sandtrack and the material of the ‘Pro-Ride

Operating Environment/Context Several different types of tracks at the Morphettville Racecourse. Training carried out on the sandtracks and the ‘Pro-Ride’ each morning. Training is carried out year round Time to carry out the rehabilitation works minimised. Critical tasks that could not be avoided  Removal of the existing contaminated sand  Placement of new clean sand.

Cement Stabilisation  Treated with 3% cement  Provided a bound layer for additional strength  Designed to mitigate material migration from the base into the sand layer. The Initiative Lime Stabilisation  Scraper used  Treated with 2% lime.  Assists in the drying of the existing base  Helped to waterproof flood prone areas of the track. Removal of the contaminated sand, lime and cement stabilisation of the existing base material, priming of this surface prior to the placement of clean sand. Sand removal  Scraper used  with a scraper and carried out in less than two days.

Remove the sand and place new base course on top of the existing base course.  Not feasible due to the required drainage of the ‘Pro-Ride’ track Excavation/Removal of existing base material and replace with a 20mm FCR.  Significantly more expensive  Increased the required time to establish as suitable base course.  Did not treat the problem  Material migration would occur much sooner Alternative Options

Outcomes Innovation Pavement loading from a horse’s hoof is one of the highest point loads a pavement is exposed to. Lime & cement stabilisation provided the endurance increasing strength and durability without harsh stones that potentially breaks free and harm the horses’ hooves. Economic Impact This stabilisation option represents great value for money and a faster alternative to get a superior project outcome. Traditionally this has been done using remove & replace which proves expensive. Productivity It was required that the job had to start and finish between race meetings therefore the task was time critical. Using this process reduced the impact on the down time of this part of the racecourse. Sustainability & Endurance This process eliminated some of the reoccurring problems that have existed in the past with the base at this location. Environmental Impact Using this process increased the amount of material that was able to be recycled and utilised site worn materials.