581WATERPROOFING MEMBRANE SYSTEM

Art. 580.06 Waterproofing Membrane System 508

580.06Method of Measurement. This work will be measured for payment as

follows.

shall conform to Article 202.07(a).

payment in place, and the area computed in square feet (square meters). The area for measurement will include only the surface of the membrane waterproofing covered with a protective cover.

580.07Basis of Payment. This work will be paid for at the contract unit price

per square foot (square meter) for MEMBRANE WATERPROOFING.

581.01Description. This work shall consist of furnishing and placing a

waterproofing membrane system over a properly prepared concrete bridge deck prior to placing of the hot-mix asphalt (HMA) surface course.

581.02Materials. Materials shall be according to the following

Item Article/Section

Note 1. The waterproofing membrane system shall consist of a penetrating primer, a built-up coal tar pitch emulsion membrane with two plies of coated glass fabric, and a 1/2 in. (13 mm) thick asphalt sand seal protection layer.

CONSTRUCTION REQUIREMENTS

581.03General. All methods employed in performing the work and all

equipment, tools, and machinery used for handling materials and executing any part of the work shall be subject to approval of the Engineer before the work is started, and whenever found unsatisfactory, shall be changed or improved as required. All equipment, tools, machinery, and containers used shall be kept clean and maintained in a satisfactory condition.

581.04Preparation of Concrete Deck. All surfaces which are to be covered

shall be thoroughly cleaned by the use of air jets, water jets, mechanical sweeper, hand brooms, or other approved methods, or as required by the Engineer until the surface is free of all sand, clay, dust, salt deposits, and all loose or foreign matter. Any accumulations of oil or grease shall be scraped off the surface of the roadway after which those areas shall be cleaned with a strong caustic solution, the residue of which shall be thoroughly flushed away with clean water before application of the primer.

Waterproofing Membrane System Art. 581.06 509 All cleaned areas shall be primed without delay as soon as they are dry. All dust and dirt shall be blown off with air jets immediately preceding application of primer. Any unusually sharp concrete edges on the deck surface which could puncture the membrane shall be corrected in a manner satisfactory to the Engineer prior to application of the primer. Exposed aggregate or rough spots shall be smoothed.

A 1/2 to 3/4 in. (13 to 19 mm) fillet of grout shall be placed in the cove area between curb, parapet, median and expansion dam faces, and the deck surface to prevent a void area where the membrane turns up the vertical face. The grout mixture shall be one part cement and two parts sand mixed with water.

Concrete surfaces, structural steel, railing, passing vehicles, etc. shall be protected to prevent their being defaced by primer or other materials being used. Should defacement occur, the Contractor shall clean surfaces on the structure to the satisfaction of the Engineer and be solely responsible and liable for damage to passing vehicles. From the time the bridge deck is cleaned and prepared for the prime coat until the HMA is spread and compacted, the only traffic permitted on the area being treated shall be the necessary men and equipment to perform the work required.

581.05Weather and Moisture Limitations. Work shall not be done during

wet weather conditions, or when the deck and ambient air temperatures are below 45 °F (7 °C). The deck shall be surface-dry at the time of the application of the primer. The membrane shall not be placed until at least 28 days after deck-concrete placement on new structures unless otherwise directed. On existing structures where the normal traffic flow is interrupted by the project work, as much drying time after the curing period shall be allowed as is feasible before membrane placement.

581.06Application of Membrane System. Pressure distributors used for the

application of the tar emulsion shall be self-propelled, equipped with pneumatic tires, and capable of applying 0.08 to 0.10 gal/sq yd (0.4 to 0.5 L/sq m) of tar emulsion over the required width of application. Distributors shall be equipped with removable manhole covers, tachometers, pressure gauges, and volume measuring devices.

Mixing and agitating equipment furnished shall be either a portable power mixer or a tank-type power mixer. A portable mixer for use in drums shall have sufficient power and propeller blades shaped to thoroughly mix and pull the material upward from the bottom of the drum. Mixing in tanks may be done in round bottom tanks equipped with a power driven mixer of sufficient capacity to maintain the emulsion in suspension.

The primer and full membrane shall extend up the curb faces and other vertical barriers to at least the elevation of the top of the surfacing. The lips of drain openings and edges of open joints, deck slab, and other openings at deck level shall be completely sealed by extending the full waterproofing course over the lip or edge.

The penetrating primer shall be applied by spraying, preferably with high pressure hydraulic equipment using hand-held spray bars that permit close control of the quantity applied. Applied at the rate of approximately 0.01 gal/sq yd (0.05 L/sq m), the quantity shall be controlled to produce a "brown coat" filling all pores and depressions but devoid of lakes or pools showing a solid film when dried

Art. 581.06 Waterproofing Membrane System 510 out. The purpose of the primer is to neutralize the concrete surface and not to produce a membrane film by itself.

Primer shall not be diluted unless ordered by the Engineer. A distributor truck shall not be used to apply the primer unless its performance has been demonstrated and its use approved by the Engineer. Surfaces shall be dry when primer is applied, and the weather and atmospheric conditions favorable for a drying period of at least four hours. Care shall be taken that the primer does not flow onto nor is applied over bituminous or mastic materials.

Coal tar pitch emulsion shall not be applied until the primer has cured according to manufacturer's recommended dry time or until all solvents that may cause bleeding of the emulsion have evaporated. The coal tar pitch emulsion coatings shall not be applied when the weather is foggy or when rain threatens, or when the atmospheric or pavement temperature is below 45 °F (7 °C).

Due to the settling that may take place in transit, the emulsion shall be thoroughly agitated by power mixers so that a homogeneous consistency is ensured for proper and uniform application.

A total of four applications of emulsion shall be applied to the deck, the fourth coat being in the form of a slurry. The slurry shall be applied at the rate of 0.30 gal/sq yd (1.4 L/sq m) in order to obtain 0.13 to 0.15 gal (0.5 to 0.6 L) of undiluted coal tar emulsion per square yard (square meter). The first three coats of undiluted coal tar emulsion shall be applied at the rate of 0.08 to 0.10 gal/sq yd (0.4 to 0.5 L/sq m). Two layers of fiberglass fabric shall be placed parallel to the length of the bridge. The necessary time shall be allowed between coats for proper setting. After the roadway surface has been properly primed and approved by the Engineer, the coal tar pitch emulsion shall be applied according to one of the two following methods.

per square yard (square meter) as required. The undiluted material shall be poured in strips on the pavement and spread with a squeegee or brush, smoothing out with a brush. This procedure shall be continued until the entire area is covered. Application can also be made by means of a heavy spray gun when approved by the Engineer. The first coat shall be allowed to dry or cure sufficiently to prevent pickup before the second coat is applied. When spreading the second coat, it shall be spread crosswise to the placing of the first coat when practicable.

applicator, the emulsion shall be applied uniformly to the surface of the pavement at the prescribed pressures and in the amount per square yard (square meter) as stated. The emulsion shall be thoroughly mixed before use. When necessary to dilute the emulsion in order to aid proper application, the emulsion may be diluted with a maximum of ten percent by volume of clean fresh water as directed by the Engineer.

In all cases, the waterproofing shall begin at the low point of the surface to be waterproofed so that water will run over and not against the laps.

Waterproofing Membrane System Art. 581.06 511 One width of the fiberglass fabric shall be laid loosely into the second coat of emulsion while the film is still wet. The fabric shall be brushed into the emulsion thereby eliminating all wrinkles and blisters, but without stretching the fabric tight. The adjoining widths of fabric shall be installed in the same fashion, side lapping the former by 3 in. (75 mm). All end laps shall be at least 12 in. (300 mm). The upper layer of fabric shall be applied in the same manner, but the laps shall extend over the lower laps by at least 6 in. (150 mm).

The fourth coat shall be a slurry top coat. The emulsion and aggregate shall be blended and premixed to produce a slurry top coat. The coal tar emulsion may be diluted up to a ratio by volume of 0.1 parts water to one part coal tar pitch, emulsion to facilitate the mixing and spreading of the slurry. The slurry shall contain a nominal 4 lb (0.5 kg) of fine aggregate per gallon (liter) of coal tar pitch emulsion.

Before application, the materials shall be proportioned accurately and mixed by suitable mixing equipment. Mixing machines for preparing the slurry may be mortar mixers, concrete mixers, or any type approved by the Engineer capable of producing a uniform mixture of emulsion and aggregate. The emulsion and the water shall be first charged into the mixer and blended into the desired consistency. Then the aggregate shall be added at a slow and uniform rate while the mixing is continued until the batch aggregate is incorporated. After all the components are in the mixer, the mixing shall continue for minimum of five minutes or as long as may be necessary to produce a smooth, free flowing, homogeneous mixture of a uniform consistency. Mixing shall be continuous from the time the bitumen is placed into the mixer until the slurry is poured into the spreading equipment.

During the entire mixing process, there shall be no breaking, segregating or hardening of the emulsion, nor balling, lumping, or swelling of the aggregate. After the required mixing period, the slurry shall be spread over the designated area while the slurry is of the proper consistency. The slurry shall be applied at the rate of 0.28 to 0.30 gal/sq yd (1.3 to 1.4 L/sq m) in order to obtain 0.13 to 0.15 gal (0.5 to 0.6 L) of undiluted coal tar emulsion per square yard (square meter).

The application of the slurry shall be either by hand methods using rubber squeegees for spreading or by any other suitable mechanical method approved by the Engineer. The slurry shall be applied at a uniform rate as specified.

A suitable spray type applicator or distributor approved by the Engineer may be used for applying the slurry. Such equipment shall be equipped with an agitator to keep the slurry uniformly mixed before and during application and so designed to uniformly spread the slurry on the roadway at the specified rate of application.

At all times, particular care shall be taken to protect the membrane from damage. Any damage which may occur shall be repaired by patching in a manner satisfactory to the Engineer. The complete membrane shall be allowed to cure for at least 24 hours before placement of the protection layer.

Art. 581.07 Waterproofing Membrane System 512

581.07Protection Layer. The fine aggregate and asphalt binder shall be

combined in such proportions that the composition by weight of the finished mixture shall be as directed by the Engineer but within the following range limits.

Fine Aggregate 90.0 to 93.0 % Asphalt Binder 7.0 to 10.0 %

The hot-mix asphalt (HMA) plant used for the manufacture of the protection course material shall be capable of producing completely coated uniform mixtures within the tolerances set forth and at a uniform workable temperature as specified by the Engineer, but not to exceed 350 °F (175 °C) for the mixture when leaving the plant.

The exact proportions, within the limits specified, shall be regulated so as to produce a satisfactory mixture with all particles coated with asphalt binder. The fine aggregate shall be mixed dry for not less than 15 seconds. The asphalt binder shall then be added in an evenly spread sheet over the full length of the mixer box. The mixing shall be continued for a period of not less than 30 seconds and at least until the aggregate is completely coated with asphalt binder.

The asphalt sand seal protection layer shall be placed and compacted according to the requirements of Section 406, except that the material shall not be mixed or placed when the atmospheric temperature is below 50 °F (10 °C). The temperature of the mix shall not be less than 290 °F (144 °C) at time of placement. The mix shall be placed and compacted so as to provide a protection layer of approximately 1/2 in. (13 mm) in thickness.

581.08Sequence of Construction Operations. The sequence of

construction operations for the waterproofing membrane systems shall be as follows.

recommended cure time]

Fabric 1.65 oz/sq yd (55 g/sq m) [Cure 4 Hrs.]

Fabric 1.65 oz/sq yd (55 g/sq m) [Cure 4 Hrs.]

581.09Method of Measurement. This work will be measured for payment as

follows.

shall conform to Article 202.07(a).

Hot-Mix Asphalt Surfacing On Bridge Decks Art. 582.05 513

computed in square yards (square meters) of bridge deck surface covered. No measurement or allowance will be made for laps, material used for extending up curb faces or other vertical barriers, material used for extensions over lips or edges, or for repairs.

581.10Basis of Payment. This work will be paid for at the contract unit price

per square yard (square meter) for WATERPROOFING MEMBRANE SYSTEM.

SECTION 582. HOT-MIX ASPHALT SURFACING ON BRIDGE DECKS

582.01Description. This work shall consist of constructing a hot-mix asphalt

582.02Materials. Materials shall be according to Article 406.02

582.03Equipment. Equipment shall be according to Article 406.03, except

vibratory rollers will not be permitted on bridge decks.

CONSTRUCTION REQUIREMENTS

582.04General. Work shall be according to Section 406, except as specified

herein.

Only a tandem roller, meeting the requirements of Table 1 of Article 406.07(a), will be permitted for breakdown rolling.

582.05Target Density. A target density will be established from tests

conducted on a calibration strip consisting of 100 ft (30 m) of HMA surface course placed on the bridge deck.

A target count rate which represents the maximum compactive effort will be determined with nuclear testing equipment within the calibration strip.

Compaction of the calibration strip with the breakdown roller shall commence immediately after the surface course is placed and shall be continuous and uniform over the entire area. All rolling operations must be completed before the temperature of the mixture drops below 190 °F (90 °C). At a minimum of two random locations within the calibration strip, a growth curve consisting of a plot of counts per minute vs. number of passes with a breakdown roller will be developed.

The growth curve at each random location will be established by using a nuclear gauge using a fast count or with a nuclear gauge using a 30-second timing cycle in the backscatter position. Tests will be made after each pass until the lowest count either raises or remains the same. At this time, mineral filler will be spread and a 4 minute (calibration) count will be taken in the backscatter position to establish the relative target density.