Concrete Repair and Overlays
NO CONCRETE REPAIRS SHOULD BE MADE UNTIL CLEANING IS COMPLETED. ALL SURFACES, JOINTS, CRACKS, AND BROKEN CONCRETE THAT IS TO BE REMOVED AND REPLACED MUST BE CLEAN. SEE CONCRETE CLEANING PROCEDURES.
Inspection and Estimating Concrete Repair
Inspect expansion joints and determine length, width and depth of missing or loose elastomeric joints. Loose (unadhered) joint materials must be removed.
Also determine if backer board is intact or must be replaced. Backer strip should be firmly in place and to a heighth such that the depth of the elastomeric sealer is no greater than ½ of the width of the joint. Cubic inches of joint divided by 230 = gallons of elastomeric joint fill needed.
Construction / Cut Joints
Inspect all cut joints to determine the amount of loose
or missing joint filler. Foam backer rod should be in place at a depth no greater than½ inch deep. Cubic inches of joint divided by 230 = gallons of CRS 6170 Joint Filler.
Inspect all cracks and categorize by width and length. Cracks 1/8 inch and
greater are to be considered moving cracks and will be treated as expansion joints. Cracks
less than 1/8 inch wide will be routed with a ¼ inch wide crack saw and filled with CRS
6170 Joint Filler. Do not use a "vee" cut to fix any crack – this will void all warranties by
Broken and Slumping Slab
Determine the area of any slab that must be sawn
and replaced. Any replacement along Expansion Joints and Construction Joints must
include replacing and maintaining those joints. Add two inches to the greatest dimension so
that the patch line will be straight and the vertical surface is flat. Include removing and
replacing one foot depth of compacted fill beneath the area.
NOTE: At any joint or crack where the slab on one side is lower than the slab on the other
side, that is an indication of curling or loss of fill and support at that area. If driving a
truck across that area shows movement or "pumping", then that area will eventually fail.
Inspect area to receive slip resistant overlay. Determine if any areas need to be filled with patch material. Locate and mark any metal protrusions that may be damaged by or cause damage to scarifiers.
Concrete cracks should be repaired prior to the overlay. Expansion and construction joints should be repaired after the overlay.
- Remove all loose expansion joints. Remove any deteriorated backer board and backer rod.
- Clean the sides of the joint to clean dry concrete – grind if necessary. Do not leave any old
joint adhesive, oils, greases, form oils or other impediments to adhesion.
- Replace any deteriorated backer board and backer rod so that firm support is in place for
the new elastomeric joint sealant. Backer materials must be at a depth no greater than½ the width of the joint. Example, a joint 2 inches wide should have sealant no more than 1 inch in depth.
- Install new elastomeric joint sealant. Use only two component chemical resistant urethane.
- Remove loose and deteriorated joint filler.
- Clean the sides of the joint to remove any old adhesive, oils, grease and other impediments
to good adhesion. Routing the joint with a crack saw may accomplish the clean out.
- Install foam backer rod at depth of ½ inch.
- Fill joint with CRS 6170 Joint Filler.
Cracks Greater than 1/8 Inch Wide
- In general cracks greater than 1/8 inch indicate concrete movement and require the same
treatment as an expansion joint.
- Establish an expansion joint by saw cutting along each side of the crack at a distance of 1
inch away form the crack and to a depth of ½ inch.
- Remove concrete to the depth of cut.
- Fill crack below the cut with CRS 6170 Joint Fill.
- Prime concrete surfaces with CRS 1030 Epoxy Primer. Allow to cure for 4 to 24 hours.
- Fill crack with two part chemical resistant elastomeric urethane.
Cracks less than 1/8 Inch Wide
- Blow cracks until they are free of debris and water.
- Route cracks with ¼ inch wide crack chaser to a depth of ½ inch.
- Seal crack below the ½ inch cut with urethane sealant.
- Fill crack with CRS 6170 Joint Filler.
Remove and Replace Broken and Uneven Concrete
- Saw cut through the slab in straight lines. Cut a minimum of 2 inches away from the
widest area of repair. Cut wider than any breakage going under the concrete.
- Remove wet or oily backfill and replace with clean fill and compact. If fill has fallen away
from under the surrounding slab, it must be replaced or grouted so that the slab is
- Drill and set dowels according to ACI and dowel suppliers recommendations.
- Dowels across joints must allow for expansion and contraction at that joint.
- Use CRS Epoxy Bonding Agent on surfaces that are not expansion joints.
- Place rebar according to ACI standards.
- Place 4000psi concrete with slump of 3 or less. Accelerate with Gill 33 additive
- Prime with CRS Epoxy Prime and Seal after initial set.
- Saw cut perimeter with crack chaser to a depth of ¼ to ½ inch deep.
- Remove all fuels, oils, grease, old coatings and anything else that is not clean concrete.
- Scarify to depth of 1/8 inch. Normally this will be below the "oil line".
- Check for any oil in the concrete. Test any suspicious area with CRS Organo-Etch. If
foaming does not occur, then the area contains oil.
- If oil is found, scarify for an additional 1/8 inch. Repeat as necessary.
- When clean concrete is obtained, apply CRS Epoxy Grout base and CRS 1575 Slip
- Install Expansion and Construction Joints.
Product List - Concrete Repair and Overlays
CRS 7000 Polymer Concrete Patching Mortar
CRS 6170 Crack and Construction Joint Filler
Expansion Joint Compound
CRS 1015 Bonding Agent (New Concrete to Old)
CRS 1110 Dowel Set Epoxy
CRS 1030 Epoxy Primer
CRS 1575 Non Skid Overlay
CRS 3010 Urethane Coating