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Epoxy Chip Seal (New Section) EPOXY CHIP SEAL (New Section)
491
Page 283
491.1

DESCRIPTION
This work consists of preparation of the existing bridge deck and furnishing and placing the
Polysulfide Epoxy with quartzite sand broadcast as the cover aggregate.
491.2

MATERIALS
Materials shall conform to the following Sections:
A.

Cement: Type III Cement, Section 750.
B.

Fine Aggregate: Section 800
C.

Coarse Aggregate: Shall conform to Section 820 for Coarse Aggregate for Bridge Deck
Resurfacing (Size No. 3) of the Standard Specifications. Coarse Aggregate to be used shall
consist of either crushed quartzite or other crushed ledge rock. If crushed ledge rock other than
quartzite is to be used, it shall be from a source approved by the Engineer.
D.

Water: Section 790
E.

Admixtures: Sections 751 and 752
F.

Grout: Grout for bonding new concrete to old concrete shall consist of equal parts by weight of
Portland Cement and sand, mixed with sufficient water to form a thick slurry. A grout admixture
shall be added to the grout mixture in accordance with the manufacturers recommendations.
G.

Grout Admixtures: Shall be a one component acrylic bonding additive. The additive shall be
one of the grout admixtures from the Approved Products List, or an approved equal as
determined by the Office of Bridge Design.
H.

Cover Aggregate: Section 805
I.

Curing: Curing materials shall conform to Section 821.1A & C. No curing compounds will be
allowed.
J.

Polysulfide Epoxy: Shall be a two component epoxy consisting of a base component and
hardener. Both shall be supplied in containers lined with a chemically resistant liner to prevent
exposure of the components to metal. The components shall be stored at temperatures greater
than 60
o
F (16
o
C). The Polysulfide epoxy shall be one of the epoxies from the Approved
Products List or an approved equal as determined by the Office of Bridge Design.
491.3

CONSTRUCTION REQUIREMENTS
A.

Surface Preparation
1.

Removal of Rubberized Asphalt Chip Seal (RACS): When removal of RACS is specified
on the plans, the removal shall be in accordance with these provisions. Alternate removal 491
EPOXY CHIP SEAL (New Section)
Page 284
techniques may be submitted to the Bridge Construction Engineer, through the proper
channels, for approval. Removal of existing RACS shall consist of heating the existing RACS
on a bridge deck to a specified temperature and removing the heated RACS from the bridge
deck surface by scraping with a front end loader and hand tools.
a.

Heating Requirements: The existing RACS on the deck surface shall be heated to a
temperature range of 125
o
F to 140
o
F (52
o
C to 60
o
C) as measured using an infrared
pyrometer. The infrared pyrometer shall be furnished by the Department. Removal of the
RACS shall not proceed until the RACS is between the specified temperatures.
Heating the existing RACS on the deck surface shall be accomplished with mobile heaters
capable of heating the RACS to the specified temperature range. The heating equipment
shall be placed directly in front of the RACS removal equipment for the full width of the
RACS removal equipment. Portable propane heaters are acceptable.
A visual indication that the existing RACS on the deck surface is nearing the desired
temperature will be the appearance of small glossy black spots on the RACS surface.
b.

Mechanical Removal Requirements: The removal of the heated RACS on the deck
surface shall be accomplished with the blade of a front end loader bucket and hand tools.
For maximum removal efficiency with the front end loader blade, the following shall be
adhered to:
1.

Maintain a sharp lubricated bucket blade. The blade and hand tools used to remove
the RACS shall be lubricated to prevent the heated RACS from sticking to the blade
or hand tools. This lubricant shall be a non-flammable commercially available
product. Apply the lubricant as necessary, as approved by the Engineer, to prevent
the heated RACS from sticking to the blade.
2.

Maintain a 60 to 70 degree angle between the bucket blade and the deck surface.
3.

Maintain as much downward force on the bucket as possible without damaging the
underlying bridge deck as approved by the Engineer.
4.

Maintain complete contact with the bridge deck and the blade during removal
operations. Rate of removal will be maintained below the speed at which the bucket
blade begins to chatter on the deck.
The Contractor shall use hand tools to remove the RACS in areas where the front end
loader could not be used for removal such as low spots on the deck surface, adjacent to
curb lines or adjacent to bridge joints.
All removed RACS shall become the property of the Contractor for his disposal in
accordance with the Standard Specifications. EPOXY CHIP SEAL (New Section)
491
Page 285
c. Acceptance Criteria: The intent of this procedure is to remove all of the aggregate and
as much of the asphalt material as possible from the deck surface. Adherence to the
construction procedures outlined in this document as approved by the Engineer shall
constitute acceptance.
2.

Removal and Replacement of Loose and Delaminated Concrete: Removal of delaminated
and loose concrete and bituminous patches (when present) shall be accomplished prior to
grinding of the bridge deck (when bridge deck grinding is specified in the plans). Removal
shall be by jackhammers or chipping hammers as approved by the Engineer. Jack hammers
and mechanical chipping tools shall not be operated at an angle in excess of 45 degrees
measured from the surface of the concrete. The edges of the resulting hole in the deck shall
be nearly vertical or tapered inward from the top down to a minimum depth of one inch. A
reversed taper will not be permitted. Saw cutting the edges of the removal area may be
required if satisfactory results can not be obtained by other means. Any reinforcing steel that
is exposed by the concrete removal operations shall be thoroughly cleaned by abrasive
blasting. Care shall be taken during the removal operations not to nick, gouge, or in any other
way damage the in-place reinforcing steel. Any damage to the in-place reinforcing steel
caused by the removal operations shall be repaired ad directed by the Engineer at no cost to
the Department.
Prior to placing concrete within the concrete removal areas, the removal areas shall be
thoroughly cleaned of loose or foreign material by abrasive blasting. The abrasive blasting
shall be to the extent that all surface laitance is removed. Abrasive blasting shall expose the
coarse aggregate and remove rust from any exposed reinforcing steel. After abrasive blasting,
the surface shall be cleaned by air blast using a compressor equipped with a satisfactory
operating filter.
Grout shall be applied on all of the existing concrete surfaces that will be in contact with the
new concrete immediately before concrete placement. The grout shall be scrubbed into the
surface in a thin and uniform coat. Care shall be taken to ensure that excess grout does not
collect in pockets, that grout is confined only to the immediate area in which new concrete is
to be placed, and that the rate of application is limited to an amount that will be covered with
concrete before it dries.
The existing surface at the time of concrete placement shall be at least 40º F (4
°
C), measured
by a thermometer placed against the surface and covered with an insulating blanket. The
concrete shall be between 45
°
F (7
°
C) and 80
°
F (27
°
C) at the time of placement and shall
be maintained at or above 45
°
F (7
°
C) for at least 72 hours.
The concrete slump at the time of placement shall be maintained between 1 and 4 inches (25
and 100 mm), and the concrete shall contain 6.5% + 1% entrained air.
The following Portland cement concrete mix design shall be used for concrete replacement: 491
EPOXY CHIP SEAL (New Section)
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Mix Design Proportions
Mix/Bag
lbs. (kg)
Mix/Cu. Yd.
lbs. (kg)
Absolute Volume
(per unit volume)
¶
Water
42.3 (19.19)
360 (213.58)
0.213675
·
Sand
140.6 (63.42)
1190 (706.00)
0.268621
Cement
94.0 (42.64)
800 (474.62)
0.149790
·
Rock
158.5 (71.53)
1342 (796.19)
0.302914
¸
Air
---
---
0.065000
TOTAL
---
3692 (2190.39)
1.000000
¶

The amount of water in this mix design is the maximum amount of water, including that
due to moisture in the aggregate, that is allowed. The water actually used should initially
be reduced, and then water added gradually, to achieve concrete that is within slump
specifications. It will be the responsibility of the Contractor to produce concrete that is in
accordance with the specifications and notes.
·
Saturated Surface Dry (Adjustments for moisture in aggregate are required)
¸

An air content of 6.5% was used for calculation.
As soon as finishing has been completed, the new concrete exposed to the deck surface shall
be given a broomed finish only.
After applying the broomed finish to the new concrete, the new concrete shall be covered with
a double layer of clean wet burlap. Within one hour of covering with wet burlap, polyethylene
sheeting shall be placed on the wet burlap and the surface cured for 48 hours. The wet burlap
and polyethylene sheeting shall be secured to the deck surface for the specified cure time by a
method to be approved by the Engineer. The curing material shall then be removed for an
additional 48 hours of a