ont>. Yahoo! is not affiliated with the authors of this page or responsible for its content.
EPOXY RESIN INJECTION (10-12-01) 1.0 G 1
EPOXY RESIN INJECTION
(10-12-01)
1.0

G
ENERAL
For repairing cracks, an approved applicator is required to perform the epoxy resin
injection. Make certain the supervisor and the workmen have completed an instruction
program in the methods of restoring concrete structures utilizing the epoxy injection
process and have a record of satisfactory performance on similar projects.
The applicator furnishes all materials, tools, equipment, appliances, labor and supervision
required when repairing cracks with the injection of an epoxy resin adhesive.
2.0

S
COPE

OF
W
ORK
[FOR EXAMPLE SEE LAST PAGE OF THIS SPECIAL PROVISION]
3.0

C
OOPERATION
Cooperate and coordinate with the Technical Representative of the epoxy resin
manufacturer for satisfactory performance of the work.
Have the Technical Representative present when the job begins and until the Engineer is
assured that his service is no longer needed.
The expense of having this representative on the job is the Contractors responsibility and
no direct payment will be made for this expense.
4.0

T
ESTING
The North Carolina Department of Transportation Material and Tests Unit obtains test
cores from the repaired concrete. If the failure plane is located at the repaired crack, a
minimum compressive strength of 3000 psi (20.7 MPa) is required of these cores.
5.0

M
ATERIAL
P
ROPERTIES
Provide a two-component structural epoxy adhesive for injection into cracks or other voids.
Provide modified epoxy resin (Component A) that conforms to the following
requirements:
Test Method
Specification
Requirements
Viscosity @ 40 ± 3°F (4 ± 1°C), cps
Brookfield RVT Spindle
No. 4 @ 20 rpm
6000 - 8000
Viscosity @ 77 ± 3°F (25 ± 1°C), cps
Brookfield RVT Spindle
No. 2 @ 20 rpm
400 - 700
Epoxide Equivalent Weight
ASTM D1652
152 - 168
Ash Content, %
ASTM D482
1 max. 2
Provide the amine curing agent (Component B) used with the epoxy resin that meets the
following requirements:
Test Method
Specification
Requirements
Viscosity @ 40 ± 3°F (4 ± 1°C), cps
Brookfield RVT Spindle
No. 2 @ 20 rpm
700 - 1400
Viscosity @ 77 ± 3°F (25 ± 1°C), cps
Brookfield RVT Spindle
No. 2 @ 20 rpm
105 - 240
Amine Value, mg KOH/g
ASTM D664*
490 - 560
Ash Content, %
ASTM D482
1 max.
Method modified to use perchloric acid in acetic acid.
Certify that the Uncured Adhesive, when mixed in the mix ratio that the material supplier
specifies, has the following properties:
Pot Life (60 gram mass)
@ 77 ± 3°F (25 ± 1°C) 15 minutes minimum
@ 100 ± 3°F (38 ± 1°C) 5 minutes minimum
Certify that the Adhesive, when cured for 7 days at 77 ± 3°F (25 ± 1°C) unless otherwise
specified, has the following properties:
Test Method
Specification Requirements
Ultimate Tensile Strength
ASTM D638
7000 psi (48.3 MPa) min.
Tensile Elongation at Break
ASTM D638
4% max.
Flexural Strength
ASTM D790
10,000 psi (69.0 MPa) min.
Flexural Modulus
ASTM D790
3.5 x 10
5
psi (2413.2 MPa)
Compressive Yield Strength
ASTM D695
11,000 psi (75.8 MPa) min.
Compressive Modulus
ASTM D695
2.0 - 3.5 x 10
5
psi (1379.0 -
2413.2 MPa)
Heat Deflection Temperature
Cured 28 days @ 77 ± 3°F
(25 ± 1°C)
ASTM D648*
125°F (52°C) min.
135°F (57°C) min.
Slant Shear Strength,
5000 psi (34.5 MPa)
compressive strength
concrete
AASHTO T237
Cured 3 days @ 40°F
(4°C) wet concrete
3500 psi (24.1 MPa) min.
Cured 7 days @ 40°F
(4°C) wet concrete
4000 psi (27.6 MPa) min.
Cured 1 day @ 77°F
5000 psi (34.5 MPa) min. 3
(25°C) dry concrete
Cure test specimens so that the peak exothermic temperature of the adhesive does not
exceed 77°F (25°C).
Use an epoxy bonding agent, as specified for epoxy mortar, as the surface seal (used to
confine the epoxy resin during injection).
6.0

E
QUIPMENT

FOR
I
NJECTION
Use portable positive displacement type pumps with interlock to provide positive ratio
control of exact proportions of the two components at the nozzle to meter and mix the two
injection adhesive components and inject the mixed adhesive into the crack. Use electric or
air powered pumps that provide in-line metering and mixing.
Use injection equipment with automatic pressure control capable of discharging the mixed
adhesive at any pre-set pressure up to 200
±
5 psi (1380
±
35 kPa) and equipped with a
manual pressure control override.
Use equipment capable of maintaining the volume ratio for the injection adhesive as
prescribed by the manufacturer. A tolerance of
±
5% by volume at any discharge pressure
up to 200 psi (1380 kPa) is permitted.
Provide injection equipment with sensors on both the Component A and B reservoirs that
automatically stop the machine when only one component is being pumped to the mixing
head.
7.0

P
REPARATION
Follow these steps prior to injecting the epoxy resin:
Remove all dirt, dust, grease, oil, efflorescence and other foreign matter detrimental to
the bond of the epoxy injection surface seal system from the surfaces adjacent to the
cracks or other areas of application. Acids and corrosives are not permitted.
Provide entry ports along the crack at intervals not less than the thickness of the
concrete at that location.
Apply surface seal material to the face of the crack between the entry ports. For
through cracks, apply surface seal to both faces.
Allow enough time for the surface seal material to gain adequate strength before
proceeding with the injection.
8.0

E
POXY
I
NJECTION
Begin epoxy adhesive injection in vertical cracks at the lower entry port and continue until
the epoxy adhesive appears at the next higher entry port adjacent to the entry port being
pumped. 4
Begin epoxy adhesive injection in horizontal cracks at one end of the crack and continue as
long as the injection equipment meter indicates adhesive is being dispensed or until
adhesive shows at the next entry port.
When epoxy adhesive appears at the next adjacent port, stop the current injection and
transfer the epoxy injection to the next adjacent port where epoxy adhesive appeared.
Perform epoxy adhesive injection continuously until cracks are completely filled.
If port to port travel of epoxy adhesive is not indicated, immediately stop the work and
notify the Engineer.
9.0

F
INISHING
When cracks are completely filled, allow the epoxy adhesive to cure for sufficient time to
allow the removal of the surface seal without any draining or runback of epoxy material
from the cracks.
Remove the surface seal material and injection adhesive runs or spills from concrete
surfaces.
Finish the face of the crack flush to the adjacent concrete, removing any indentations or
protrusions caused by the placement of entry ports.
10.0

B
ASIS OF
P
AYMENT
Payment for epoxy resin injection will be at the contract unit price per linear foot (meter)
for Epoxy Resin Injection. Such payment will be full compensation for all materials,
tools, equipment, labor, and for all incidentals necessary to complete the work. 5
EXAMPLE
2.0 S
COPE OF
W
ORK
Using Epoxy Resin Injection, repair all cracks 5 mils (125
µ
m) wide or greater in the
interior bent columns and caps, in the ends of the girders, in the cantilevered portion of the
ends of the girders, and in the cantilevered portion of the superstructure deck on the
downstream side.
Repair the column cracks to the top of the footings. Make the underwater repairs when
water surface elevation is low and the water is still. For underwater repairs, use
manufacturer recommended materials.
Repair any crack, void, honeycomb or spall area unsuitable for repair by injection with
epoxy mortar.
NOTE: This part of the Special Provision must be written for each project.