Method statement for water tank GRP lining
The purpose of this method statement is to describe
the procedure for the application of the performed GRP lamination
in
the RCC Water tanks. These documents describe
the GRP lamination applied in the Potable water Tanks, Sump pits and Manholes.
Equipment:
- Roller
- Scaffolding
- Ladders
- Polythene sheets
- PPE
Materials:
- White Gelcoat - 2900 W
- GP Resin – TP1110
- Catalyst - Luperox
- CTG MAT – 300/450 CSM
Executing.
1-Clear the surface to remove all honeycombs and smut
materials.
2- Any small hole’s undulations on the concrete surface and
horizontal and vertical corners shall be properly chamfered and rectified by
the main contractor as per revised concrete method statement.
The below steps is to be followed on continuity basis as the
chemical reaction will be carried out during the application process in wet
condition forming Glass Reinforced Plastic. As there will be no delay intervals
between each layer.
3- Apply primer as GP
resin on the surface of the wall using roller.
4- E glass surface mat(300gm/m²) or glass reinforced fabric
layers are used consisting of approximately 60%-70% GP Resin by weight.
5- Above step No. 4 is repeated with E glass surface
mat(450gm/m²) approximately 60%-70% GP Resin by weight to ensure a thickness of
4mm.
6- Thickness of reinforced layers is generally 0.08-1.00mm
which provides a protective barrier against corrosion and all glass fiber used
as fiber glass reinforcements shall be type E glass that shall comply with BS
4396 glass fiber chopped strand mat for the reinforcement of polyester resin
system as per manufacturer’s data sheet attached.
7- Finally White Gelcoat is applied using 2900 W with
wax for proper filling of pinholes and
to make the complete tank surface smooth.
8- Guarantee will be provided for any manufacturing defects
in workmanship and material.
Method of Laying Procedure.
1- The required amount of catalyst or hardener and other
ingredients such as accelerator or permitted filler shall be accurately
measured and thoroughly mixed to 60%-70% resin and 30% fiber.
2- Smooth rolling pressure shall be implemented during
laying time as excessive rolling pressure may be avoided because mat
distribution may be disturbed, or it may break the fiber strands.
3- It shall be ensured that good adhesion is obtained
between successive layers of the laminate to avoid any peel off between the layers
due to improper use of rolling.
3- In all types of laminates adjacent pieces of laminate
including feather edged reinforcement shall be overlapped by not less than
100mm. So far as is practicable, all joints shall be staggered through the
thickness of laminate and in no case shall joints coincide in adjacent
layers.
4- When directionally biased reinforcement is used care
shall be taken to ensure that the high strength fibers are adequately lined in
the correct direction to give the required strength. Any spillage drips or runs
shall be suitably removed.
5- All items shall be cured in accordance with the resin
supplier’s instruction, whenever possible this shall be done at the
manufacturer’s works. 24–36-hour clear curing time shall be allocated to
achieve proper bonding and setting of laminated layers on the surface of
concrete walls.
6- Should the curing time has not elapsed, and water filled
prior to the above said time duration the above-mentioned warranty will be
void.
7- Repairing work should be conducted by the same
lamination. First the Laminating area is
kept dry then make rough the surface with grinder. The joints of the adjacent
sides are also cleared and laminated overlapping on both sides not less than
100mm, if required.
8- The above lamination is kept for 48 hours for proper drying.