SUNEPOXY 368
The epoxy resin used in
construction is typically a light amber coloured liquid about the viscosity of
a heavy motor oil. By itself epoxy resin is not an adhesive. It must be
combined with a hardener or curing agent, typically an amine or a polyamide. Once
combined by thorough mixing, a chemical reaction begins and as it is taking
place, individual molecules of the resin and hardener from chemical bonds or
linkages. These linkages are very strong and occur not only in a linear
direction, but in three dimensions – respond to as ‘cross-linking’. When epoxies
fail to cure properly, due to poor curing or off-ratio proportions for example,
the structure of this cross linking is poor. Consequently the material does not
harden completely and may seem rubbery, soft or tacky.
Properties
An epoxy with the lowest
viscosity was selected for injection all these days. However, to-day epoxies
are being formulated with viscosities close to that of water (one centipoise). These
work well in thin cracks.
ASTM Type I
|
Sunepoxy 368
|
Viscosity, Centipoise max
2000
|
400 – 500 cp
|
Get time, minutes 30
|
45 – 60 minutes
|
Bond Strength min (psi) 1000
|
17 N/mm2 (2500
Psi)
|
Compressive Strength
7 days min (psi) 8000
|
68 N/mm2 (10000
Psi)
|
Tensile Strength
7 days min (psi) 5000
|
34 N/mm2 (5000
Psi)
|
Ratio
Based on the formulation,
specific amounts of resin and hardener are required for a full reaction and
proper cure. SUNPOXY 368 has a 3:1 volume based ratio.
Mixing
Mix one batch at a time using a
bucket and drill (connected to a stirrer). The drill speed is to be low 300-400
rpm. Use cage type mixing paddles. Keep the mixing paddle below the surface of
the material as much as possible Half-way through mixing, stop mixing and
scrape the mixing paddle and the side and bottom of the bucket or transfer the
contents to another bucket and complete the mixing. Mix injection resin for
three minutes. Do not over mix with high-speed drill, this can generate
excessive heat.
Surface capping
Formulations of epoxy that
easily permit the paste to be applied to the surface of the crack to contain
the injected resin, are generally used. It would be advantageous to use
formulations that permit crack injection as soon as one hour after capping.
Instruction for use
Remove loose, disintegrated and
porous concrete at cracks and joints and repair the same either with epoxy
mortar or polymer modified mortar. Thereafter drill the injection holes to the
depth of two to four inches. The distance of injection points depends upon the
cracks, extent of damage and the dimensions of the structural elements. Fix the
nipples and clean all the loose dust particles from the cracks and holes by
blowing compressed air through at the nipples in succession. The above mixture
of epoxy and hardener can be injected by means of suitable pump at pressure of
50-100 psi.
Packing
SUNPOXY 368 is available in 20
kg, 5 kg and 1 kg packing.
HARDENER is available in 5 kg,
1 kg packing.
Shelf life
Twelve months when stored in
original closed container.
