Rural Councils are seeing the benefits of innovative solutions to roadworks with the application of PolyCom Stabilising Aid to treat their existing marginal materials and construct a reliable and sustainable pavement.
One such Shire had experienced significant pavement failures along an important sealed road recently and applied PolyCom to reconstruct the road.
The sealed road is trafficked by heavy vehicles and subject to many years of inundation following heavy rain. This has caused the subgrade to become extremely saturated and unable to support the pavement. Consequently the road failed in a number of areas and was providing an unacceptable level of service to the users. This was affecting the local economy including farmers who rely on an efficient road network to service their properties.
Council’s traditional solution (at great expense) was to excavate and sidecast the existing gravel subbase (also saturated to some degree) to subgrade level and attempt to bridge the highly saturated subgrade with scalpings. Any usable gravel subbase is then placed over the top followed by a 150mm layer of high quality crushed rock, sourced from over 70km away and sealed.
The traditional approach outlined above is expensive, slow and becoming unsustainable. The remoteness of the Shire is such that it relies on its own internal resources to carry our road works and was looking for an innovative solution.
With many surrounding Shires experiencing the benefits that PolyCom Stabilising Aid brings in terms of improved strength and workability and ease of application, the Shire used PolyCom to not only treat the weak subgrade but also the sub base.
The subgrade was treated to a depth of 200mm and the subbase to a depth of 150mm. The result was a subgrade with adequate strength to support the pavement and a much stronger, well-bound subbase without the need to import additional gravel. The resheet overlay was also reduced from 150mm to 100mm due to the strength benefits gained by treating the subgrade and subbase with PolyCom Stabilising Aid.
PolyCom works were completed quickly and economically using only internal Council staff and standard plant, ie grader, water cart, pad foot roller and multi-wheeled roller, saving the expense of hiring specialised equipment.
The PolyCom treated materials provided a pavement meeting required specifications with significant cost savings and time, as well as ensuring greater utilisation of internal Council resources.