530WATERPROOFING CONCRETE SURFACES

New Hampshire Department of Transportation Standard Specifications – 2016 Description

1.1This work shall consist of waterproofing concrete surfaces shown on the plans or ordered with two coats of a cement base

waterproof coating for concrete. Materials

2.1All components of this system shall be compatible and shall be furnished by the same supplier.

2.2All materials shall be delivered to the job site in sealed containers bearing the manufacturer’s original labels.

2.3The color when dry shall be a shade of gray matching the concrete.

2.4Materials used for this specification shall be a product as included on the Qualified Products List.

2.5The mixture shall not contain calcium chloride or sodium chloride.

Construction Requirements

3.1Preparation or Surfaces.

3.1.1 The concrete face to be coated shall be cleaned of all laitance, dirt, dust, oil, efflorescence, paint, and other foreign material by the use of sandblasting or waterblasting. Suitable traps shall be installed in sandblasting or waterblasting equ ipment to prevent oil from being deposited on the surface. 3.1.2 Surfaces which have been cured by the use of curing compound shall not be coated with waterproof finish until at least 30 days have elapsed since curing compound application.

3.2Brush and Flat Waterproofed Finish.

3.2.1 All work shall be performed by an experienced Contractor who is familiar with water proofing work and with the materials specified herein. 3.2.2 No application is to be made when atmospheric temperature is 45 ° F or below, or if it is expected to drop below 45 ° F within 24 hours after application. Do not apply to frozen or frost -filled surfaces. If the application is made during hot weather, cool the surface with clean water first. 3.2.3 All materials shall be mixed according to the manufacturer’s printed instructions and a copy of such instructions shall be maintained on the project. 3.2.4 The cement base waterproof coatings shall be applied by the use of a masonry brush to a slightly dampened surface. The material shall be cured in accordance with the manufacturer’s recommendations. Sufficient material must be applied to fi ll and seal all pores and voids to achieve a uniform appearance. 3.2.5 The cement base, acrylic latex, coating shall be applied at the rate recommended by the manufacturer. 3.2.6 The cement base, polymer-modified, coating shall be applied at the rate recommended by the manufacturer. 3.2.7 Whenever construction or contraction joints appear in the existing or new concrete to be coated, the joints shall be tooled to allow bond breakage of the coating at the joint. Method of Measurement

4.1Waterproofing concrete surfaces will not be measured, but shall be the square yard final pay quantity in accordance with

109.11of coated surface within the limits shown on the plans

Basis of Payment

5.1Waterproofing concrete surfaces is a final pay quantity item and will be paid for at the Contract unit price per square yard

complete in place in accordance with 109.11. Pay item and unit:

530.3Waterproofing Concrete Surfaces (F) Square Yard

New Hampshire Department of Transportation Standard Specifications – 2016

Description

Water repellent shall be applied to the concrete surfaces shown on the plan or as ordered. Surfaces to be treated shall normally

consist of the following portions of all bridges: concrete curbs, sidewalks (top, fascia, bottoms), wingwalls, piers, and abutment face walls and bridge seats when not coated with epoxy coating. Materials

Water repellent (Silane/Siloxane) shall be a product as included on the Qualified Products List.

Construction Requirements

General. All caulking, patch, and joint sealers shall be installed prior to application of the water repellent. Concrete surfaces

shall have cured a minimum of 14 days and shall be dry prior to the application of water repellent. Minimum substrate and ambient application temperatures shall be as noted on the Qualified Products List for the product used except as allowed in 3.1.2 and 3.1.3. Do not apply when substrate surface temperature exceeds 85°. 3.1.1 All surfaces specified for treatment, that require finishing, shall be protected from freezing and de-icing chemicals until coated with water repellent. All finished surfaces specified for treatment must be treated before winter shutdown. 3.1.2 If the project schedule requires that surfaces be coated outside the product application temperatures listed in the Qualified Products List, those surfaces shall be recoated during the next construction season with the same product when the application temperature is within the listed temperature range and other conditions meet manufacturer’s recommendations durin g the next construction season. Prior to reapplication of water repellent, the surface shall be thoroughly cleaned by water blasti ng and allowed to dry. 3.1.3 If cold weather concreting practices as descr ibed in 520.3.7 are being followed, the 14- day provision of 3.1 is waived. The concrete shall be coated as soon as it is dry after the five-day period specified in 520.3.7 and it shall be protected from freezing until coated. Concrete that is treated with water repellent under these conditions shall be recoated as described in 3.1.2.

Water repellant (silane/siloxane) shall be applied at the heaviest coverage recommended by the manufacturer. Ambient

application temperatures, except as allowed in sections 3.1.2 and 3.1.3, shall conform to the product application temperature listed on the Qualified Products List. 3.2.1 A test application shall be performed on the surface to be treated, to ensure compatibility, using the same equipment to be used on the project. After a minimum of three days, the Engineer shall test for waterproof effectiveness by applying water t o the surface. If the water beads up and is not readily absorbed, the test is positive. 3.2.2 The Contractor shall follow the manufacturer’s instructions in the method of preparation of the concrete and application of the sealer. 3.2.3 The Contractor shall protect the concrete surface from rust staining. Any staining that does occur shall be removed by mopping with a solution containing 1lb. of oxalic acid powder per gallon of water. After 2 or 3 hours, rinse the surface with clear water, scrubbing at the same time with a stiff brush. Tough stains may require a second treatment. If rust stains still persist, other means of removal may be allowed by the Engineer. Areas that had been coated with water repellant prior to removal of rust stains shall be recoated at the application rate specified in 3.2. Method of measurement

Water repellent (Silane/Siloxane), applied to surfaces within the limits shown in the plans or specified herein and at the rate

required will be measured by the gallon.

4.2Water repellant used to recoat areas where rust stains were removed will not be measured for payment.

4.3The Engineer’s estimated quantity of Water Repellant (Silane/Siloxane) is based on an application rate of 150 sf/gal.

Basis of Payment

Water repellent will be paid for at the Contract unit price per gallon, complete in place. The reapplication of water repellent

as required in 3.1.2 and 3.1.3 will be done at the Contractor ’s expense unless the required reapplication was due to circumstances beyond the Contractor’s control, as determined by the Engineer.

5.2Removal of rust stains and recoating with water repellant will be at the Contractor’s expense.

5.3The pay quantity of Water Repellant (Silane/Siloxane) shall be the actual amount used as per 534.3.2.

Pay items and units:

534.3Water Repellent (Silane/Siloxane) Gallon