Here at New Dawn, we pride ourselves on being available to help our clients (current, past and future) at every stage of the construction process. We’ve recently finished on this carpark in Boronia for an award winning builder. But it was a long process to get here!
The town planning approval for this whole childcare centre was only going to be approved if the extremely large messmate eucalyptus tree at the front of the property could be retained and a car parking solution that protected the tree could be provided.
As part of the planning process, we (New Dawn) provided information to the landscape architects and Knox council about:
- Pavement construction methodology
- Load capacity and surface durability and maintenance
- Tree protection measures to be undertaken during excavations
- How to avoid the need for subbase compaction
Council had some concerns and we were able to alleviate them with further information.
Excavations and site preparation
Under AS 4970-2009 (Protection of Trees on Development Sites), machine excavation is a restricted activity that is excluded from tree protection zones. Under the standard, permission from the determining authority (i.e. council) may be authorised under supervision from the project arborist.
Therefore before we could commence excavations for the pavement, council’s arborist met with our team onsite and discussed in detail the permitted excavation activities.
Council permitted us to remove friable topsoil, grass and mulch within the TPZ as long as the roots were not encountered. All excavations were performed with a toothless mud bucket and material was removed in layers of 20-30 mm in order to avoid damage to roots.
Some areas required filling, so we used 12 mm bluestone screenings as a fill material, specifically chosen as they are self-compacting and free draining, meaning no compaction of the subbase was required in compliance with AS4970-2009 and the permit conditions. A heavy duty geotextile blanket was installed between the subbase and the undisturbed natural ground.
Permeable concrete base installation
Once the site was excavated and levelled, we installed our permeable concrete base. A 200 mm base with SL92 galvanised reinforcing means the pavement can handle heavy duty loadings as expected for a commercial premises car park.
Our custom integrated steel edging was installed on any exposed edges, and appropriate rebates and reinforcing was provided for areas of upstand kerb to be installed after.
Once again council was present to inspect the subbase and geotextile fabric, reinforcing and compliance with the landscape plan prior to pouring.
Prepour inspection complete and ready to go!
Permeable concrete pour underway
Permeable paving installation
After completion of the last areas of adjacent concrete, we returned to install the resin bound paving. Our resin bound paving works were completed in the final week before handover to ensure the final pavement was brand new and sparkling before handover.
As with all of our permeable installations, we proudly issued our clients a compliance certificate of permeability and tree protection and a full warranty and aftercare guide.