Specifications and additional Information - Boral

Planning and Design
BOOK
3
PAGE
B4
Flexible Laying System (Unbound Sand)
Installation Guidelines for
Flexible Laying System with
Unbound Sand
� For details on the materials specified in these guidelines, please
refer to the ‘Materials Specification’ later in section B.
Drainage
Surface Run-Off
Paving should be installed so that water will not pond within
the paved area. Adequate falls toward designated water
channels and/or stormwater drains should be provided in
the base course and/or levelling screed.
Bedding Sand Drainage
After extended rainfall, water can penetrate the joints and
enter the bedding sand, particularly when the pavement
is new. This can result in movement of the bedding sand
and rocking of the pavers under traffic. The water captured
bedding sand layer should be drained into the drainage
system. Refer to Fig B1 and Fig B2 for recommended
drainage methods.
The use of geofabrics is recommended in this application to
ensure there is no erosion of the bedding or jointing sand
via the drainage of water from the bedding sand.
Expansion Joints
Expansion joints are generally not required when pavers are laid
over unbound bedding sand and 3-5mm joints are incorporated
between adjacent pavers. This system allows flexible movement
of the pavers for expansion and contraction.
Boral
Pavers
Bituminous seal
Bedding sand
Base course
Drainage pit
Natural soil
Geofabric filter
covering pipe inlet
PVC pipe (min 20mm
dia.on three sides of pit
Pit grate
Fig B1 — Drainage of Bedding Sand into Drainage Pit
In large areas of flexible paving where expansion and
contraction is to be expected, control joints should be
considered.
Edge Restraint
Edge restraints should be provided around the periphery of
pavements to the full depth of the paver and bedding sand.
Edge restraints should be capable of preventing the loss of
bedding sand and preventing the sideways movement of the
pavers. The edge restraints must also be capable of accepting
the design traffic loads. Edge restraints should be in place
prior to installing the bedding sand where possible.
Some important detailing requirements for edge restraints
include:
Following compaction, the top of pavers should finish
2-3mm above the abutting top surface of the edge
restraint to which they are draining so that water will
not pond on the pavement.
The edge restraint should have a vertical or near-vertical
side on the face that abuts the pavers.
The base course should extend below the edge restraint
for its full width (to minimise the likelihood of the edge
restraint itself being disturbed) except in situations such
as walls or pits.
Where the edge restraint is in the form of a standard
road-authority kerb, gutter/channel or dish drain, the
requirements of that authority in relation to concrete
quality should be followed. Elsewhere the use of a Grade
N32 concrete is recommended.
Geofabric filter
covering pipe inlet
Boral Pavers
Bituminous seal
Bedding sand
Base course
Subsurface drain
PVC pipe (min 20mm
dia. at 5m centres)
surrounded with
concrete backfill
Agricultural drainage pipe
(100mm dia. typical)
Natural soil
Kerb and
gutter
Fig B2 — Drainage of Bedding Sand into Sub-surface Drain