3-Attachment B, SPECIAL PROVISIONS - Micro.pdf

Attachment B – 2026 OP3 Microsurfacing

SPECIAL PROVISIONS

MICROSURFACING

1.0 DESCRIPTION: This work shall consist of the application of Polymer modified micro-surfacing to an existing road surface. The Polymer microsurfacing shall be a mixture of modified emulsified asphalt, mineral aggregate, mineral filler and water properly proportioned, mixed and spread on the road surface in accordance with this Special Provision and as directed by the Engineer.

2.0 MATERIALS:

A. Emulsified Asphalt: The emulsified asphalt shall be CSS-1HM (Cationic). It shall show no separation after thorough mixing and shall conform to the requirement of the Standard

Specifications of Kansas Department of Transportation for "Emulsified Asphalt, CSS-

1HM", Section 1203. A minimum of 3.0% Polymer Solids content, certified from an approved source, shall be mixed into the asphalt emulsion by an approved emulsion manufacturer. The Polymer modified emulsified asphalt shall be so formulated that when the paving mixture is applied at a thickness of one inch with the relative humidity at not more than 50% and ambient air temperature of at least 75° F it will cure sufficiently that normal traffic can be allowed in one hour's time after application with no damage to the

Micro-surfacing.

B. Mineral Aggregate: The mineral aggregate shall be chat aggregate which is a by-product of the milling of lead and zinc ores, or approved equal and shall conform to the following requirements.

KDOT Type II ISSA Type II

Passing Passing

3/8" sieve 99-100% 100%

No. 4 sieve 86-94% 90-100%

No. 8 sieve 45-65% 65-90%

No. 16 sieve 25-46% 45-70%

No. 30 sieve 15-35% 30-50%

No. 50 sieve 10-25% 18-30%

No. 200 sieve 5-15% 5-15%

Resistance to Degradation (ASTM C131 grading D) 20% maximum loss

Soundness of Aggregate (ASTM C88) 15% maximum loss

Sand Equivalent Value (ASTM D2419A) 55 minimum

LA Abrasion (AASHTO T96) 25% maximum loss

The aggregate shall conform in all other respects to the requirement of the Standard

Specification of Kansas Department of Transportation for "Aggregate for Slurry Seal and

Modified Slurry Seal" Section 1110.

For residential the aggregate shall be ISSA Type II and for Arterial it shall be a blend of

50% KDOT Type II and 50% ISSA Type II.

C. Mineral Filler: The mineral filler shall be a recognized brand of non-air entrained

Portland Cement that is free from lumps. It may be accepted upon visual inspection.

Attachment B – 2020 OP3 Microsurfacing

D. Water: The Water shall be potable and shall be free of harmful soluble salts.

E. Other Additives: Any material added to the micro-surfacing mixture or any of the component materials shall be approved by the Engineer prior to incorporation and use.

F. Fiber Reinforcement: The fiber reinforcement must be a glass fiber designed to be used in paving applications. Must be alkali and acid resistant and have a minimum tensile strength of 1,700 MPa.

Rate of application will vary from 0.15 to 0.20% of dry weight material to mixture. Final application rate will be directed by the Engineer.

Slurry-FIL ™ manufactured by Owens Corning ® is a product of known quality and accepted performance or approved equal.

3.0 MIX DESIGN AND PROPORTIONING: A qualified laboratory shall develop the mix design and present certified test results to the Engineer for acceptance. The Engineer shall approve all materials and methods prior to use. The component materials shall be proportioned within the following limits:

% Polymer Modified Emulsion 7.5 min. to 8.5 max. by dry

(Residual) weight of aggregate

% Mineral Filler 1.5 min. to 3.0 max. by dry weight of aggregate

The mineral aggregate shall be weighed by means of scales approved by the Engineer. polymer modified emulsified asphalt shall be weighed by means of approved scales or may be measured by volume and converted to weight of emulsified asphalt.

4.0 CONSTRUCTION REQUIREMENTS:

A. Mixing: The material shall be mixed by a micro-surfacing mixing machine which shall be a continuous flow mixing unit able to accurately deliver and proportion the aggregate, Polymer modified emulsified asphalt, mineral filler and water into a revolving multi-blade mixer and discharge the thoroughly-mixed product on a continuous flow basis. The machine shall have sufficient storage capacity for aggregate, Polymer modified emulsified asphalt, mineral filler and water to maintain an adequate supply to the proportioning controls. The machine shall be equipped with self-loading devices, which shall provide for the loading of all materials while continuing to lay micro-surfacing, thereby eliminating unnecessary construction joints. The mixing machine must be operated in this continuous manner.

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.

The aggregate feed to the mixer shall be equipped with a revolution counter, or similar device, so the amount of aggregate used may be determined at any time.

The emulsion pump shall be the positive displacement type and shall be equipped with a revolution counter, or similar device, so that the amount of emulsion used may be determined at any time.

The mixing machine shall be equipped with a water pressure system and nozzle type spray bar to provide a water spray immediately ahead of and outside the product discharge opening in the mixing machine.

The mixing machine shall be equipped with an approved fines feeder that shall provide a uniform, positive, accurately metered, predetermined amount of the specified mineral filler at the same time and location that the aggregate is fed.

In areas that are called out to be fiber reinforced, the contractor must use an appropriate fiber as discussed in the materials section above. This introduction of this fiber to the mix must be automated with the ability to cut fiber at various lengths. These fibers shall be introduced during the mixing process prior to placement.

B. Spreading: The modified micro-surfacing mixture shall be spread uniformly by means of a mechanical type squeegee box, equipped with augers to spread the materials uniformly throughout the box and flexible material in contact with the road to prevent loss from the box. The rear flexible seal shall act as a strike-off and shall be adjustable. Rut-filling equipment will require an adjustable steel strike-off plate. The spreader shall be maintained to prevent loss of the micro-surfacing product in sealing super elevated curves. The mixture shall be spread to fill all cracks and small holes and leave a uniform application of micro-surfacing on the surface.

The seam where two passes join shall be neat appearing and uniform. If, in the opinion of the Engineer, the seam is rough enough to cause a noticeable effect on steering of an automobile, the seam shall be removed and a new micro-surfacing patch applied.

All excess material that overruns in gutters shall be removed or squeegeed back as directed by the Engineer.

All excess material shall be removed from the ends of each job site immediately and not vary in uniformity.

When needed, all joints, radii, ends and returns will be squeegeed as directed by the

Engineer.

All discolored curbs and sidewalks shall be cleaned and flushed immediately, before material sets.

All material tracked or lost past the ends of the job site shall be cleaned up before the sealing crew leaves for the next location.

Longitudinal joints shall be placed on lane lines. Excessive overlap will not be permitted.

The finished microsurfacing must have a uniform texture that is free of scratches, tears, and other surface irregularities. The Contractor shall repair the surface if any of these conditions exist:

more than 1 surface irregularity that is 1/4 inch (6 mm) or wider and 10 feet (3 m) or longer in any 100 foot (30 m) section of the modified micro-surfacing;

more than 3 surface irregularities that are 1/2 inch (13 mm) or wider and more than

6 inches (150 mm) long in any 100 foot (30 m) section of the modified slurry seal;

any surface irregularity that is 1 inch (25 mm) or wider and more than 4 inches

(100 mm) long.

The finished longitudinal and transverse joints in the modified micro-surfacing must be complete and uniform. The Contractor shall repair the joints if any of these conditions exist:

build-up of modified micro-surfacing material at the joints;

uncovered areas at the joints;

longitudinal joints with more than 1/2 inch (12 mm) vertical space between the surface and a 4 foot (1.2 m) straightedge placed perpendicular to the joint.

transverse joints with more than 1/4 inch (6 mm) vertical space between the surface and a 4 foot (1.2 m) straightedge placed perpendicular to the joint.

The edges of the modified micro-surfacing must follow the centerline, lane lines, shoulder lines, and curb lines. The Contractor shall repair the edges if they vary more than inches (75 mm) from a 100 foot (30 m) straight line (or a 100 foot (30 m) arch on a curved section).

Use methods approved by the Engineer to correct deficiencies in the modified micro-surfacing. The repaired surface must be dense with a uniform texture. Material used to correct surface deficiencies in the micro-surfacing will not be measured for payment.

C. Weather Limitations: The mixture shall be spread only when the atmospheric temperature is at least 50°F and rising and the weather is not foggy or rainy. The mixture shall not be spread when the forecasted atmospheric temperature for the following 24-hour period is below 32°F.

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: 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 is required spread a dry chat material over freshly applied micro in front of drive approaches when requested by the property owner for access and thru the intersection of all cross streets as to provide a means of travel for traffic on those cross streets. The contractor is required to sweep up and remove the excess dry chat material after the applied micro is cured and will not be damaged by the sweeping operations. The cost of the dry chat material, application and spreading, and sweeping and removal is incidental to the Microsurfacing Bid Items.

Traffic shall be carried through construction on this project. Such traffic shall be carried on existing pavements. The Contractor will be responsible for coordination of access with abutting properties within the limits of the construction. The Contractor’s representative on the job site and the City’s representative or inspector will meet with affected tenants of such property and mutually resolve any problems which require resolutions related to vehicular access to private property. Some locations may require that vehicle parking on certain streets be temporarily prohibited. The

Contractor will be required to coordinate arrangements for closing the various streets to vehicular parking in a manner approved by the City Traffic Engineer. During non-peak hours, two-way traffic may be carried in one lane with flagpersons and appropriate signing when the Contractor is working on the project. Movement of emergency vehicle will be given the right-of-way over other vehicles at all times.

Any damage done by traffic to the microsurfacing shall be repaired by the Contractor at the

Contractor's expense.

All materials, labor, equipment and incidentals required for Traffic Control, including temporary striping, shall be considered SUBSIDIARY to the price bid per square yard for “Microsurfacing".

7.0 METHOD OF MEASUREMENT: The completed modified micro-surfacing shall be measured by the square yard of micro surfacing placed.

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 "Micro-Surfacing". This price shall be full compensation for furnishing all materials, labor, equipment, and incidentals necessary to complete the work.