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Course 1 – Granular bedding material

  1. Granular bedding material must be vibrated into place using appropriate compaction equipment or tamped by hand. A vibrating plate attached to a steel block with dimensions appropriate to the width of trench and depth to the top of Course 1 may be used for this purpose.
  2. If the granular bedding material settles during vibration or tamping such that voids are formed, it must be topped up and re-vibrated or re-tamped as appropriate.

Course 2 – Indicator infill material

  1. This material must be installed using an appropriately shaped funnel or nozzle to completely fill the trench to within 15 mm to 10 mm of the finished surface level, to create an effective bond on both sides of the slot.
  2. It must be distinctively coloured to help prevent future works from damaging services in the micro trench.

Course 3 – Surface infill material:

  1. This is installed above the indicator infill material using an appropriately shaped shoe to completely fill the remaining depth of the trench, to restore the surface profile and to form an overlap seal onto the asphalt surface each side. Unless requested otherwise by the authority, this material must be black or dark grey in colour.
  2. The overlapping element of the surface infill material must be no more than 3 mm thick. The width of the finished reinstatement must be the slot width plus a minimum of 20 mm either side up to a maximum overall width of 125 mm measured at any single point.
  3. In carriageways and cycle tracks, before setting, Course 3 must be over scattered with a 3 mm dry, dust free, hard stone aggregate (with a minimum initial PSV of 60) to provide early life skid resistance and texture depth.
  4. In footways and footpaths, a nominal 1 mm size dry, dust free, hard stone aggregate (with a minimum initial PSV of 60) may be used if requested by the authority.
  5. Indicator and surface infill materials must be made of the same base resin material and be compatible with each other.