other damage. Damaged portions shall be mechanically cut away.
Reinforcing steel to match existing shall be installed where existing
reinforcing is badly corroded or damaged. Lap splices shall be as required
by code. If necessary, bars shall be fastened with tie wires.
3.4
FORMWORK ERECTION
Formwork shall be erected in accordance with the detail drawings to ensure
that the finished concrete members conform accurately to the indicated
dimensions, lines, elevations, and finishes. Deflection shall not exceed
1/360th of each component span or distance between adjacent supports.
Deflections and tolerance shall not be cumulative. Form liners shall be
installed as necessary to provide the required finish. Forms shall be
coated with form release agents before reinforcement is placed.
3.5
CONCRETE REPAIR
3.5.1
General Requisites
Repairs shall be accomplished in accordance with ACI C-10, ACI C-20, ACI 301,
and ACI 304R. Cracks shall be repaired, if required, per ACI 224.1R.
Detailing shall be per ACI SP-66. Repaired surfaces shall match adjacent
existing surfaces in all respects. Formwork as necessary to reconstruct
concrete to match adjacent surfaces shall be provided. Voids shall be
filled flush with adjacent surfaces. Products shall be used in accordance
with the manufacturer's instructions.
3.5.2
Spalls
Spalls less than 25 mm 1 inch deep, where indicated to be repaired, shall
be drypacked with an approved patching mortar. Spalls greater than 25 mm 1
inch deep shall be excavated and patched with concrete.
3.5.3
Patch Anchors
Surface areas to be patched which do not have reinforcement or other metal
embedments which will be placed in the patching concrete and mortar shall
be provided with patch anchors. Patch anchors shall be provided to ensure
that the patch is tied to the existing concrete structure. Patch anchors
shall be provided within the excavation at a frequency of at least one
patch anchor per 0.10 square meter square foot of patch plan surface area;
specific locations for patch anchors shall be as indicated. Small
handheld, low-speed rotary masonry drills shall be used to produce holes in
the existing concrete, within the limits of the excavations for the patch
anchor installation.
3.5.3.1
Holes
Holes shall be drilled into the existing concrete substrate material of the
excavation using rotary (non-hammer) drills. Holes shall have a diameter
3.2 mm 1/8 inch larger than the anchor diameter. The holes shall be
drilled to a depth of 100 mm 4 inch, except as otherwise indicated or
directed. Drill holes shall be produced to ensure that the holes do not
penetrate completely through the concrete, and will provide at least 25 mm
1 inch of cover around the drill hole. Holes shall be cleaned by water
blasting to remove drill dust and other debris and then blown dry with
filtered, dry, compressed air. Drill holes shall be conditioned in
accordance with the epoxy adhesive manufacturer's recommendations.
SECTION 03900
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