water for all cleaning operations. Perform a preliminary washing as soon
as the chipping and trimming are completed to remove loose materials and
dust particles.
Clean surfaces to which new concrete is to be bonded in
accordance with Section 03301A CAST-IN-PLACE STRUCTURAL CONCRETE FOR CIVIL
WORKS, paragraph CONSTRUCTION JOINT TREATMENT. Final cleaning shall remove
all laitance, carbonation, scum, dirt, oil, grease, and loose or
disintegrated concrete. Perform additional surface chipping to remove
coarse aggregate that is undercut by cleaning process. Perform such
additional chipping as determined necessary by the Contracting Officer at
no additional cost to the Government. Wire brush or sandblast metal
surfaces against which concrete is to be placed to remove rust and other
contaminants which would prevent proper bond with the concrete. Perform
final cleaning immediately prior to concrete placement. Protect all work
from contamination during all phases of cleanup and preparation prior to
repair.
3.6.3
Waste Water Disposal
Dispose of waste water employed in cutting, washing, and rinsing of
concrete surfaces in a manner such that the waste water does not stain,
discolor, or affect exposed surfaces of the structures, or damage the
environment of the project area. The method of disposal shall meet all
requirements of Section 01355A ENVIRONMENTAL PROTECTION.
3.7
SURFACE REPAIRS
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NOTE: Dry-pack mortar is also typically used for
small spalled areas with high depth to surface area
ration. Polymer-modified mortar, polymer-modified
concrete and cement-based concrete are typically
used for larger repair areas.
**************************************************************************
Place dowels and anchors as shown on the contract drawings. [Construct
formwork in accordance with Section 03101A FORMWORK FOR CONCRETE.]
3.7.1
Epoxy Mortar
Prime surfaces with epoxy resin binder. Scrub prime coat into surface with
a stiff bristle brush. Make coating approximately 0.5 mm (20 mils) 20 mils
thick. Place epoxy mortar while primer is still tacky. Apply at a
thickness recommended by the manufacturer. Work mortar into place and
consolidate thoroughly so that contact surfaces are wetted by the mortar.
Finish surface of mortar to the required texture. Do not feather edge
epoxy mortar onto adjacent surfaces.
3.7.2
Epoxy Concrete
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NOTE: Do not place epoxy concrete in layers greater
than 25 mm one inch in thickness. This is to avoid
heat buildup and subsequent thermal contraction.
**************************************************************************
Prime dry cavity surfaces with epoxy resin using a stiff bristle brush.
Make coating approximately 0.5 mm (20 mils) 20 mils thick. Place epoxy
concrete while primer is still tacky and in layers not exceeding 25 mm (one
inch)one inch thick. Use vibratory floats, plates, or hand tampers to
SECTION 03931
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