4-Attachment J - Scrub Seal Specifications.pdf

Attachment J, 472-2026-086186

SPECIAL PROVISIONS

Scrub Seal

1.0 DESCRIPTION: The work shall consist of but not limited to furnishing all labor, materials, equipment and transportation for the application of the Polymer Modified

Asphalt Surface Sealer. Application of aggregate. The work shall be done in the following order: Preparing the pavement surface; applying the Polymer Modified Asphalt Surface

Sealer and scrubbing the applied emulsion sealer with a scrub broom as specified herein;

applying aggregate, brooming the aggregate with a secondary broom when specified, rolling the aggregate; and sweeping up and disposing of excess aggregate off of the job site in accordance with this Special Provision and as directed by the Engineer.

2.0 MATERIALS:

A. Emulsified Asphalt: Bituminous material for seal course shall be an approved polymer modified emulsified asphalt CRS-2P. CRS-2P emulsified asphalt shall meet the requirements of KDOT Standard Specifications, Section 1202. The polymer modified emulsified asphalt CRS-2P shall have a minimum elastic recovery of 50 percent when tested by the procedure as identified below. The emulsified asphalt supplier will be required to furnish the City with certification that the emulsified asphalt conforms to the above specifications.

ELASTIC RECOVERY TEST

Scope: The elastic recovery of a polymer modified asphalt cement is evaluated by the percentage of recoverable strain measured after elongation during a conventional ductility test. Unless otherwise specified, the test shall be made at a temperature of 77°F + 0.9°F (25°C + 0.5°C) and with a speed of 5 cm/min +

5.0%.

Referenced Documents:

ASTM D113: Ductility of Bituminous Materials

ASTM E11: Specifications for Wire Cloth Sieves for Testing Purposes

Apparatus: Mold - The mold shall be similar in design to that described for use in the ductility test (ASTM D113), Figure 1, except that the sides of the mold assembly, parts a and a' shall have straight sides producing a test specimen with cross-sectional area of 1 cm²

Water Bath - The water bath shall be maintained at the specified test temperature, varying not more than 0.18°F (0.1°C) from this temperature. The volume of water shall be not less than 10 cm and shall be supported on a perforated shelf not less than 5 cm from the bottom of the bath.

Testing Machine - For pulling the briquet of bituminous material apart, any apparatus may be used which is so constructed that the specimen will be continuously immersed in water as specified while the two clips are pulled apart at a uniform speed without undue vibration.

Thermometer - An ASTM 63°C or 63°F thermometer shall be used.

Scissors - Any type of conventional scissors capable cutting polymer modified asphalt at the test temperature.

Procedure: Prepare test specimens and condition as prescribed by ASTM D113.

Elongate the test specimen at the specified rate to a deformation of 10 cm.

Immediately cut the test specimen into two halves at the midpoint using the scissors. Keep the test specimen in the water bath in an undisturbed condition for one hour.

After the one hour time period, move the elongated half of the test specimen back into position near the fixed half of the test specimen so the two pieces of polymer modified asphalt just touch. Record the length of the test specimen as X.

Report: Calculate the percent recovery by the following procedure:

Recovery, % = 10 - X x 100

B. Aggregate (Lightweight): Lightweight aggregate shall consist of expanded shale processed by the rotary kiln method with 100 percent Fractured Faces and 100 percent Ceramic coating.

a) Physical Properties - Lightweight aggregate shall conform to the following specifications:

Dry-loose weight at 35 to 55 lbs per cubic foot

Absorption less than 4%

Los Angeles wear less than 25%

Soundness ration max. 0.90

b) Gradation - 100% minus 1/4" and less than 8% minus No. 200 Sieve. Material should be clean and uniform with nearly single size.

4.0 CONSTRUCTION REQUIREMENTS:

A. Preparation: Prior to the Scrub Seal operation, the Contractor shall remove all existing thermoplastic striping, thermoplastic legends and raised pavement markers within the scrub seal limits. When removing the raised pavement markers the Contractor shall remove excessive adhesive left on pavement caused from the removal of raised pavement markers. Removal shall be done to the satisfaction of the Engineer.

Prior to the Scrub Seal operation, all personnel covers, drain inlet covers, monument covers, and all other utility covers shall be protected from the

Contractor’s scrub seal operations by applying a sheet of plastic, cut to fit, or placing a plastic bag over the exposed facilities or other methods approved by the

Engineer. All traces of plastic, residual emulsion and chips shall be removed from all personnel covers, drain inlet covers, monument covers, and all other utility covers as quickly as possible, after the application of the scrub seal and/or prior to final acceptance of the project.

Immediately prior to the scrub sealing operations, the Contractor shall sweep the entire surface.

Individual volume or weight controls for proportioning each material to be added to the mix shall be provided. Each material control device shall be calibrated and properly marked.

At least 48 hours prior to the beginning of scrub seal operations, the Contractor shall notify all affected property owners, residents, businesses and agencies by an approved, written notice detailing streets and limits of work to be done and the hours of work. At least 48 hours prior to the beginning of scrub seal operations, the Contractor shall post all streets that are to be worked upon with approved “No

Parking – Tow Away” signs at one hundred (100) feet intervals. These signs shall also state the day of the week and hours of no parking. If the work is not completed on the day scheduled, the Contractor shall re-notify and re-post the affected streets as stated above.

B. Application: All incidental work such as surfacing of driveway aprons and returns shall be done concurrently with the surfacing of the street proper. The scrub seal shall be applied 0”-4” from the lip of the gutter. Where a curb exists without gutter, the scrub seal shall be applied 0”-4” from the face of curb when receiving a cape. If a cape is not specified then the scrub seal shall be placed from edge of pavement to edge of pavement. Where no curb or gutter exists, the scrub seal shall be applied from edge of pavement to edge of pavement. The edges of the limits of the scrub seal application on both sides of the street shall be maintained in a neat and uniform line. Scrub seal shall not be applied on concrete gutters or pads unless directed by the Engineer.

The application of Polymer Modified Asphalt Surface Sealer shall be applied when ambient temperature is above forty (40) degrees Fahrenheit and rising. The polymer modified asphaltic rejuvenating emulsion shall not be placed if the ambient temperature during the twenty four curing period (24) hours is expected to be below twenty-five (25) degrees Fahrenheit. The termination time of application shall be determined by the Engineer.

The areas to be scrub sealed shall have the Polymer Modified Asphalt Surface

Sealer applied with a distributor truck to the pavement surface at a rate of 0.25 to

0.40 gallons per square yard. For cul-de-sacs, turnout pockets, elbows and curve returns the use of the scrub broom will not be required. The actual emulsion sealer application rate required will be determined by the pavement surface condition and aggregate the aggregate used. The actual application of the emulsion sealer shall be determined by the manufacturer’s representative and / or the Engineer.

The Polymer Modified Asphalt Surface Sealer temperature when applied shall be at a minimum of 110 degrees Fahrenheit. For smaller areas the emulsion sealer may be applied with a wand. The emulsion sealer shall be immediately broomed to fill cracks and voids. The emulsion scrub broom shall be as described below:

SCRUB BROOM EQUIPMENT (Exhibit A): Immediately following the application of the emulsion sealer to the road surface, the material shall be scrubbed with a scrub broom for the purpose of forcing the emulsion sealer into the existing surface and distributing the emulsion sealer evenly over variable road surface contours.

The scrub broom frame shall be constructed of metal. The scrub broom shall be attached to and pulled by the distributor truck. The scrub broom must be equipped with the means to mechanically raise and lower the scrub broom off and onto the road surface at designated points of completion and start up. It shall be tow able in the elevated position to the next area of construction. The weight of the broom assembly shall be such that it does not squeegee the emulsion sealer off the roadway surface.

The main body of the scrub broom shall be a minimum of 6’-9” wide and 8’-0”

(ft) deep. The maximum width of the rigid frame at any point shall not exceed 8’-

0”. The depth shall not exceed 10’-0” The nearest and furthest members, paralleling the back of the spreader truck, and diagonal members shall be equipped with street brooms. The leading member and the trailing member shall have broom heads angled at 15 degrees off the centerline of the supporting member. The diagonal members shall have broom heads attached in line with the centerline of the supporting member. Each individual street broom attached to the scrub broom assembly shall be 3 ½” w x 6 ½” h x 16” L and have stiff nylon bristles. Bristle height is to be maintained at a minimum of 5”. The scrub broom shall be equipped with a min. of 2- hinged wing assemblies attached to the main body not to exceed

4’-6” (ft) in total per side, with diagonals and equipped with street brooms. The purpose of the maximum rigid frame width and the hinged wing extensions is not only for maximum width of 16’ (ft) but to maintain the scrubbing process evenly as contours and cross-sections change across the existing road surface .

The application of the Polymer Modified Asphalt Surface Sealer and the scrub broom operation shall cease 40’ (ft) prior to the end of the street section or intersection. The remaining emulsion sealer shall be drug out by the scrub broom, and the remaining emulsion sealer required to complete the pass shall be applied only by the spread truck (boot truck), at the specified rate.

Immediately following the scrubbing of emulsion sealer, aggregate shall be applied at the rate specified. The rate shall be adjusted up or down so that no “bleed through” occurs during rolling.

The aggregate shall be spread evenly by a mechanical spreader. Aggregate ¼” minus less shall be broomed with a SECONDARY AGGREGATE BROOM to fill all cracks and voids, unless otherwise directed by the Engineer. The

SECONDARY AGGREGATE BROOM when used must be equipped with the means to mechanically raise and lower the broom off and onto the road surface at designated points of completion and start up. The design shall be similar in design to that of the emulsion broom. The exception would be that the internal diagonal members shall be used for stiffness and shall not have broom heads attached to the cross members. It shall be pulled by a vehicle following the aggregate spreader to ensure even distribution of the aggregate, and penetration of the aggregate into the cracks. The weight of the broom assembly shall be such that it does not roll or turn the aggregate that is set in the emulsion sealer. The use of the SECONDARY

AGGREGATE BROOM can be used immediately after the application of the chips or after rolling. The sequence of operation will be determined by the Engineer.

A minimum of two self-propelled pneumatic-tired rollers shall be used for the required rolling of the aggregate. The pneumatic-tired rollers shall be in good working condition and actively rolling at all times during the scrub seal operation.

The pneumatic-tired rollers shall be a minimum 5 tons. The pneumatic-tired rollers shall be operated in such a manner to prevent the dislodging of newly applied aggregate.

During the sweeping process the Contractor shall use a backpack blower to clear driveways, gutters and sidewalks of excess aggregate at the end of each day until the street is micro surfaced. The Contractor shall wait a minimum of one week after the scrub seal application before applying other surface treatments as specified.

The Contractor shall exercise care to prevent oil from being deposited on concrete surfaces. Each day the Contractor shall remove oil from the surfaces not designated to caped. No additional streets shall be scrub sealed until this clean-up has been performed. The method of the oil removal shall be approved by the

Engineer.

Contractor shall install temporary raised pavement markers on arterial streets once the scrub seal is cured until the roadway surface is ready for permanent raised pavement markers.

C. Equipment:

The following equipment to be used for the scrub-seal shall be as follows

A. An asphalt distributor for application of the emulsion sealer shall have a full circulation spray bar that is adjustable to at least sixteen (16) feet wide in two (2) feet increments and capable of heating and circulating the emulsion simultaneously. It must have computerized rate control for adjusting and controlling the application from the cab that is adjusting by

.01 gallons per square yard increments. The distributor shall also be equipped with a volume measuring devise and a thermometer for measuring the emulsion temperature in the tank.

B. A SCRUB BROOM (As shown on next page) and as described herein shall be used to scrub the emulsion sealer after application.

C. A self-propelled aggregate spreader with front discharge that can evenly distribute aggregate.

D. A minimum of two (2) pneumatic rollers weighing at least five (5) tons each.

E. Two (2) mechanically powered kick-brooms or vacuum type brooms.

F. A back pack blower for removing excess chips during the sweeping operation.

D. Surface Preparation: The area to be sealed shall be thoroughly cleaned of all vegetation, loose aggregate, dirt, mud, and other objectionable materials. The area to be sealed shall be cleaned immediately prior to sealing. Water used in pre-wetting the surface shall be applied at a rate to dampen the entire surface without any free flowing water ahead of the spreader box.

5.0 RATE OF APPLICATION: The rate of application shall be as directed by the Engineer.

The quantity noted in the proposal is only an estimate.

6.0 MAINTENANCE OF TRAFFIC: Detouring of traffic for this work will not be provided and closing of road for this work shall be at the direction of the Engineer and so coordinated to result in the least practicable delay and inconvenience to the public. Adequate means shall be provided to protect the micro-surfacing from damage by traffic until such time that the mixture has cured sufficiently so that it will not adhere to or be picked up by the tires of vehicles. The contractor shall provide signs, barricades and flaggers necessary to control traffic around the area under construction. Application of the mixture shall be suspended early enough each day to permit traffic to safely travel over the completed work before dark. Any damage done by traffic to the micro-surfacing shall be repaired by the

Contractor at the Contractor's expense. Barricades, signs and other warning devices will be in accordance with the Federal Highway Administration "Manual on Uniform Traffic

Control Devices" provisions for "Traffic Controls for Street and Highway Construction and Maintenance Operations", 1988 Edition (latest revision). A written traffic control plan or schematic shall be provided by the Contractor for the Engineer's approval prior to beginning the work. Appropriate Traffic Control standards are available upon request from the Engineer. All materials, labor, equipment and incidentals required for the "Maintenance of Traffic", including temporary striping, shall be considered SUBSIDIARY to the price bid per square yard for “Scrub Seal".

7.0 METHOD OF MEASUREMENT: The completed Scrub Seal shall be measured by the actual square yard applied to the pavement.

8.0 BASIS OF PAYMENT: The amount of completed and accepted work shall be paid for at the contract unit price bid per square yard for "Scrub Seal". This price shall be full compensation for furnishing all materials, labor, equipment, and incidentals necessary to complete the work.