1.22.1 GENERAL (1993)
When called for on the plans, in the specifications or ordered by the Engineer the following requirements shall be applicable to the treatment of exposed concrete surfaces upon completion of the structure or precast member. Water repellent treatment is not intended to be used on surfaces subject to hydrostatic pressure.
1.22.2 SURFACE PREPARATION (2003)
a. Concrete surfaces shall be cleaned by light sand or shot blasting, followed by vacuum cleaning to remove all traces of curing compounds, laitance, dirt, salt, oil, grease, fluids or other foreign material that would prevent penetration or adhesion of the sealer.
b. Concrete surface shall be clean and dry or as recommended by manufacturer. If concrete is subjected to rain or moisture the surface should be allowed to air dry for a minimum of forty-eight (48) hours before treatment.
c. The cleaning process shall not alter the existing surface finish unless specified by the Engineer as an intentional part of the design.
1.22.3 ENVIRONMENTAL REQUIREMENTS (2003)
a. Volatile Organic Compound regulations may vary by individual state. Therefore, it is mandatory that materials selected for use be in total conformance to the applicable legislation of the state within which the work will be performed. b. Ambient and surface temperatures at time of application shall be as specified by the manufacturer but not less than 40
degrees F (5 degrees C) or greater than 100 degrees F (38 degrees C).
c. No rain shall be predicted for a minimum of 12 hours after completion of water repellent treatment. d. No precipitation shall occur within 24 hours preceding application.
e. No wind shall be predicted of velocity, per the manufacturer, greater than that which will cause an improper application rate to drift, etc.
f. Adjoining surfaces of other materials shall be protected unless solvent carrier is certified as harmless to these materials by water repellent manufacturer.
1.22.4 APPLICATION (2003)
a. The penetrating water repellent treatment solution shall be applied in strict accordance with manufacturer’s instructions and not diluted or altered unless specified by the manufacturer. Equipment for the application of the
water-repellent treatment shall be clean of foreign materials and approved by the Engineer before use. The sealer shall be applied by brushing, spraying or rolling, as recommended by the manufacturer.
b. Surface treatment of new concrete prior to 28 days curing is not permitted, unless approved by the manufacturer and the Engineer.
c. The sealer manufacturer should be consulted on the recommended treatment of cracks. d. Follow all safety precautions required by occupational jurisdiction.
e. A minimum of two (2) coats of water-repellent treatment is recommended to achieve uniform coverage. The second and each additional coat shall be applied perpendicular to the previous coat. Care shall be taken when applying each coat, such that running or puddling does not occur. Each coat shall be allowed to dry for a minimum of two (2) hours before the next coat is applied. The final coat shall be allowed to dry according to the manufacturer’s instructions before applying ballast and track.
1.22.5 MATERIALS (2003)
a. The penetrating water repellent material shall consist of an isobutyltrialkoxy silane, n-octyltrialkoxy silane or iso- octytrialkoxy silane dissolved in a suitable solvent that will produce a hydrophobic surface covalently bonded to the concrete. Only one (1) brand and specific type of penetrating sealer shall be used on each individual concrete element (i.e., each pier, deck, abutment, etc.). The penetrating sealer must be a one part liquid, with no field blending required. b. Qualities of the material to be furnished for the project shall be tested and results certified by an independent testing
laboratory with report provided to the owner. The following tests shall be performed on standardized laboratory specimens:
(1) Water Penetration. ASTM C642–50 Day Soak less 1% Absorption (untreated specimen 4%, 0.2% absorption). (2) Water Penetration. National Cooperative Highway Research Program Report 244–21 Day Soak–Effective
Average Minimum 80% (Series II).
(3) Vapor Transmission. National Cooperative Highway Research Program Report 244–Minimum 100%. (4) Surface Appearance. No change in surface appearance or texture.
(5) Penetration. Oklahoma DOT OHD L-34 Visible Average 0.15 inches (6) Drying Time. Dry and ready for use 1 hour after application.
(7) Accelerated Weathering. ASTM G23–2000 hours are weatherometer–Maximum 3% loss of effectiveness. (8) Water Penetration. Alberta DOT Type 1 Class B minimum.
(9) Salt Water Ponding. AASHTO T-259–Maximum 1.50 lb per cubic yard at 1/16 inch to 1/2 inch; 0.75 lb per cubic yard at 1/2 inch to 1 inch.
(10) Traction – ASTM E303. No change when treated surface is compared to control surface. Measured in British Pendulum Numbers.
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1.22.6 QUALITY ASSURANCE (1993)
a. The manufacturer shall provide written certification of the quality of the product being offered and issue a warranty as to its effectiveness when it is applied in accordance with the manufacturer’s specifications.
b. Manufacturer shall have an established Quality Assurance Program with the Program available to the owner or buyer. c. Pre-Test. An eight square feet (0.75 square meter) test panel on the job shall be treated and evaluated in accordance
with the primary water repellent manufacturer’s recommendations and written test procedures which would allow the water repellent to cure for a minimum of 5 days. Two test cores (minimum 3 inches (75 mm) diameter and 3 inches (75 mm) deep) should be taken at locations determined by the Engineer. In the presence of the manufacturer, or one of its representatives, the cores should be split by chisel. One core should be retained by the Engineer. The water repellent material shall have penetrated the core at least 1/8 inch (3 mm) (avg) and shall appear as a band of non-wettable concrete.
d. Test Data. All test data submitted by the water repellent manufacturer must be data generated by an independent testing laboratory. Product tests must be totally controlled by the testing laboratory. Specimens cannot be pre-treated by the manufacturer.
1.22.7 DELIVERY, STORAGE AND HANDLING (1995)
a. Materials shall be delivered to job site in manufacturer’s original undamaged containers with labels and seals intact. b. Materials shall be stored in accordance with manufacturer’s requirements and in a dry area with a temperature range of
not less than 32 degrees F (0 degrees C) and not more than 120 degrees F (49 degrees C). Adequate ventilation shall be provided, away from sources of ignition.
c. Manufacturer’s application instructions and Material Safety Data Sheet shall be consulted for additional safety instructions.