This item deals with a variety of concrete treatments including concrete surface sealing, horizontal crack sealing, vertical crack sealing and waterproofing.
Improper surface preparation is one of the main reason we see sealer failures. When the sealer is applied to a damp, dusty or laitance laden surface the sealer cannot gain the proper adhesion and peels off, normally in sheets.
Make sure the Contractor is standing a reasonable distance away from the surface being blasted. This should normally be within 18 inches. Using a 7000 psi water blast from 6 feet away does not gain the level of cleanliness they need to apply the sealer correctly.
There is a Qualified Product List (QPL) for these materials maintained by the Office of Materials Management (OMM) located under 705.23
These sealers are clear by nature, but are to be tinted with a vanishing dye. Due to this fact it will be difficult to see where progress ended on the preceding day. Establish a method to mark the stop point that will not permanently be visible in the completed work.
Ensure that test sites include a variety of surfaces: Horizontal, vertical, inverted, steel formed finish, troweled, floated, rubbed, etc.
HMWM stands for High Molecular Weight Methacrylate.
If the Contractor supplies 3 part HWWM meaning the promoter, resin and initiator are supplied separately be aware the promoter and initiator will react violently with each other. This chemical reaction is so violent that these are components normally arrive to the jobsite on different trucks.
Poor surface cleanliness is the major problem encountered in the field. Dust and debris clog up the cracks and do not allow the HMWM to penetrate effectively.
Be sure to insist that the Contractor coordinate his initial application on the project with the presence of Manufacturer’s Representative. This Representative should be a technical representative in lieu of a sales representative.
The application of sand is required to give the sealed surface a rough texture to assist with traction. If the sand is applied after the resin begins to harden it will not become embedded and will merely brush off with the first wave of traffic leaving a potentially slick surface.
There is a Qualified Product List (QPL) for this material maintained by the Office of Materials Management (OMM) located under 705.15
Proper surface preparation is essential for SRS to perform properly. The manufacturer’s representative must be on-site and sign off that the surface preparation is adequate.
The Contractor is required to perform a test section(s). This section(s) should incorporate all of the surface types to be treated. This is due to the fact that the test sections are to confirm application rates and appearance which will depend on the orientation and porosity of the concrete.
After the treatment has cured and prior to opening to traffic, the treated surfaces that experience vehicular or pedestrian traffic should be washed down with water. In some instances the SRS treated surfaces have become very slick when first being exposed to water. It is better to have this initial exposure in a controlled scenario versus allowing it to be the first rain with traffic running on it.
There is a Qualified Product List (QPL) for this material maintained by the Office of Materials Management (OMM) located under 705.24
There is a Qualified Product List (QPL) for this material maintained by the Office of Materials Management (OMM) located under 705.25
Make sure the requirement for the presence of the manufacturer’s representative is enforced even if the Contractor has vast experience with this feature of work.
Note the Contractor may refer to the injection ports and “straws”.
Take core samples as soon as the epoxy has cured. This is more critical on larges jobs as the method of epoxy injection may have to be altered if it is not achieving adequate penetration. On small one day type job this will not be possible.
There is a Qualified Product List (QPL) for this material maintained by the Office of Materials Management (OMM) located under 705.26
Care should be taken while placing backfill against areas that have received waterproofing. The waterproofing can be damaged either by direct contact of the equipment or by using backfill materials which contain large sharp edged rocks.
a. Document type of material used (make and model)
b. Quantity of material used and application rate
c. Area treated or sealed in square yards and/or lineal feet of crack repaired
d. Contact information for Manufacturer’s Representative that is on-site (where required)
e. Atmospheric conditions and substrate temperatures
2. Waterproofing (512.08)
a. All surfaces clean and dry prior to placing waterproofing
i. Type A, B, and D
1. Amount of primer used
2. Temperature of bituminous material
3. Document amount of bituminous required and amount used.
4. Document lap of fabric
ii. Type 2 and 3 membrane
1. Temperature at time of application
2. Document lap of membrane
3. Type 3 surface joints sealed