Plastiline™ - Humes

6 Incorporation in spun concrete pipes
6.1 The Plastiline shall be incorporated in the body of
the concrete pipe by embedment of the locking keys in the
concrete immediately following the manufacture of the
pipe.
6.2 The Plastiline blanket shall be so placed in the pipe
that keys are circumferential in direction. This will allow a
free escape to the unlined part of the pipe for any moisture
or fluid which may accumulate between the lining and the
pipe wall.
6.3 The extent of the pipe circumference to be covered
by the Plastiline shall be specified by the client. It is only
necessary to line that area of concrete which is subject to
corrosion (see page 6).
6.4 Immediately upon completion of manufacture of the
pipe the Plastiline is to be accurately positioned in the
pipe and the locking keys fully embedded in the concrete in
such fashion as to develop the pull-out strength stipulated
in Clause 11.4.
6.5 Keys adjacent to the ends of the pipe barrel shall not
be closer than 13mm to the ends of the barrel and the
maximum distance between keys on either side of a pipe
joint, with an undeflected pipe fully ‘home’ shall not
exceed 130mm for field welded pipes. For factory welded
pipes incorporating spigot end caps and/or socket inserts,
the distance of the first key from the pipe end shall not
exceed 130mm.
6.6 Embedment of Plastiline into concrete pipes can
produce minor circumferential corrugations which will be
more evident in smaller diameters. These corrugations
shall be in addition to the tolerances allowed under
Australian Standard AS 4058 and will have no significant
effect on the carrying capacity of the pipes because of
the smoothness of Plastiline and the smooth flow
conditions.
7 Incorporation in vertically cast pipes
7.1 Plastiline sheet shall be so placed on the inner
mould that keys are running in the longitudinal direction.
A short length of each locking key shall be removed to
provide weep channels at intervals of no more than 2.5m
along assembled pipelines, to ensure that there is no
build-up of hydrostatic pressure.
7.2 The sheet shall be placed under slight tension and
held firmly against the inner mould, to prevent leakage of
mortar between blanket and mould. The sheet can be a
pre-formed tube, or blanket held in place initially by metal
or plastic straps and finally secured at the vertical edges
under strips of rigid plastic, held by screws inserted from
inside the mould.
If the lining is a pre-formed tube, relief of hydrostatic
presure is provided by leaving a short length of the
circumference unwelded (at the invert) when the pipeline
is assembled.
7.3 Reinforcement shall be secured by plastic bar
chairs or other method of support which will not damage
the sheet.
7.4 In large diameter vertically cast pipes, adjacent linings
will normally be joined in the assembled pipeline by
102mm joint strip as shown in the joint detail type P1
(see page 11).
2250mm diameter Plastiline pipes.
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