Section 02550 ASPHALT CONCRETE PAVEMENT

Section 02550

_{ASPHALT CONCRETE PAVEMENT}

PART 1 - GENERAL

1.1 THE REQUIREMENT

A. The CONTRACTOR shall furnish all tools, equipment, materials, and supplies and shall perform all labor required to complete the work as indicated in the Contract Documents and specified herein.

B. Street pavement within public or private rights-of-way and pavement areas within the treatment plants shall be removed and replaced in all areas of construction in conformance with the details on the Contract Documents, if any; as specified herein; and in accordance with the provisions of permits issued by the agency having jurisdiction. Where no details are provided, existing pavement within the treatment plants shall be replaced with pavement and base in kind to match existing pavement removed.

C. New pavement shall be as indicated on the Contract Documents and as specified herein, or in accordance with the provisions of permits issued by the agency having jurisdiction. Unless otherwise indicated, new pavement shall be as indicated herein.

D. All materials and procedures shall comply with the rules and regulations of the South

Coast Air Quality Management District.

1.2 RELATED WORK SPECIFIED ELSEWHERE

A. The requirements of the following sections and divisions apply to the Work of this section. Other sections and divisions of the Specifications, not referenced below, shall also apply to the extent required for proper performance of this Work.

1. Section 02200, Earthwork

1.3 REFERENCE SPECIFICATIONS, CODES AND STANDARDS

A. All Work specified herein shall conform to or exceed the applicable requirements of the referenced portions of the following publications to the extent that the provisions thereof are not in conflict with other provisions of these Specifications.

B. Comply with the applicable editions of the following codes, regulations, and standards.

1. Codes and Regulations:

California Test 205 Determining Percentage of Crushed Particles California Test 304 Preparation of Bituminous Mixtures for Testing California Test 367 Recommending Optimum Bitumen Content (OBC)

2. Industry Standards:

AASHTO T 180 Standard Method of Test for Moisture-Density Relations of Soils Using a 4.54-kg (10-lb) Rammer and a 457- Millimeter (18-inch) Drop

SSPWC “Green Book,” Standard Specifications for Public Works

Construction

C. Comply with the applicable reference Specifications as specified in the General

Requirements and the Additional General Requirements.

D. All materials and procedures shall comply with the rules and regulations of the South

Coast Air Quality Management District.

1.4 CONTRACTOR SUBMITTALS

A. Submittals shall be made in accordance with the General Requirements, Additional

General Requirements, and as specified herein.

B. Samples: Prior to the delivery of specified aggregate to the site, the CONTRACTOR shall submit samples of the material for the ENGINEER’s acceptance in accordance with SSPWC Section 4-1.4. Samples shall be typical of materials to be furnished from the proposed source and in conformance with the specified requirements.

C. The CONTRACTOR shall formulate a job-mix formula using the Hveem method with the optimum asphalt content determine by California Test 367 and submit it to the ENGINEER for acceptance.

D. Certificates:

1. Twenty days prior to the delivery of aggregates, asphalt materials, and paving mixes to the project site, the CONTRACTOR shall submit to the ENGINEER certificates and test results of compliance of such materials with these Specifications.

2. Where laboratory testing is specified herein, the CONTRACTOR shall employ an independent testing laboratory to conduct such tests and submit certificates of the test results.

1.5 QUALITY ASSURANCE

A. Quality assurance will be provided by the ENGINEER. OCSD will provide inspection at the asphalt plant and laboratory services within 50 miles of the geographical limits of OCSD.

B. The CONTRACTOR shall be responsible for quality control.

PART 2 - PRODUCTS

2.1 GENERAL

A. The CONTRACTOR shall make all tests necessary to locate a source of materials that meet the Specifications. Final acceptance of the aggregate material will be based on tests of material taken by the CONTRACTOR from the compacted base course.

2.2 AGGREGATE BASE

A. Aggregate base shall conform to the provisions of the latest edition of the Standard Specifications for Public Works Construction (SSPWC), Subsection 200-2.2, Crushed Aggregate Base, or Subsection 200-2.4, Crushed Miscellaneous Base. Crushed miscellaneous base shall have only the fine gradation. Aggregate shall be asbestos free.

B. In lieu of the second sentence of SSPWC, Subsection 200-2.4.1, at least 65 percent by weight of the material retained on the No. 4 sieve shall be a crushed particle as determined by California Test Method No. 205.

C. Evaluation of gradation and sand equivalent test results shall conform to the provisions of SSPWC, Subsection 400-1.4. The gradation and sand equivalent requirements of SSPWC, Subsection 200-2.4 shall be the moving average requirements.

2.3 ASPHALT CEMENT

A. Asphalt cement for binder shall be AR-4000 paving asphalt and shall conform to the requirements of SSPWC Section 203-1, Paving Asphalt.

2.4 PRIME COAT

A. Asphalt to be used for a prime coat shall be liquid asphalt SC-250 and shall conform to the requirements of SSPWC Section 203-2, Liquid Asphalt.

2.5 TACK COAT

A. Asphalt emulsion shall be CSS1 or CSS-1h and shall conform to the requirements of

SSPWC Section 203-3, Emulsified Asphalt.

2.6 EMULSION-AGGREGATE SLURRY

A. Materials for emulsion-aggregate slurry shall be as specified in SSPWC Subsection

203-5.

2.7 ASPHALT CONCRETE

A. Asphalt concrete for paving the designated area shall be Class C2-AR-4000 hot-plant mix and shall conform to the requirements of SSPWC Section 203-6, Asphalt Concrete.

B. Asphalt content in the pavement shall be 5.5 percent to 6.0 percent by weight. Asphalt concrete (AC) paving shall conform to III-C2-AR-4000 as defined in SSPWC, Subsection 400-4. Asphalt shall be viscosity grade AR 4000 or AR-8000.

C. Aggregate shall be in accordance with SSPWC Subsections 400-1.1 and 400-1.2. Aggregate shall be asbestos free.

D. Coarse aggregate shall consist of material of which at least 75 percent by weight shall be crushed particles in lieu of the requirements of SSPWC, Subsection 400-4.2.3.

2.8 WEED KILLER

A. Weed killer shall be Karmex 80, as manufactured by Dupont Chemical Company or

Diuron 4L, as manufactured by Drexel Chemical Company, Or Equal.

2.9 TEMPORARY PAVING

A. All pavement areas removed for trenching operations shall be replaced with 2 inches of temporary asphalt concrete paving mix within one day after compaction is accepted by the ENGINEER. Cross streets are to be paved with temporary pavement on the same day that excavation is made. Temporary pavement shall be maintained so that a smooth traversable surface free from ruts, depressions, holes and loose gravel is available at all times for vehicular traffic.

B. The cost of temporary asphalt paving is considered to be included in the Contract unit prices for the Work and no extra compensation will be made to the CONTRACTOR.

2.10 ASPHALT CONCRETE OVERLAY

A. This work shall be performed by the Cold-in-Place (CIP) method of pavement. This procedure consists of cold planing (CP) the in situ bituminous materials to a depth of 3 to

4 inches. The material is then pulverized, sized, and mixed with an additive. Virgin aggregate may be added to modify Reclaimed Asphalt Pavement (RAP) characteristics. An asphalt emulsion or a recycling agent is added and then the material is placed and compacted.

B. The Contractor shall submit a mix design tested in accordance with Mix Design Procedures of this Special Provision using materials obtained directly from the project site from cores. The contractor shall obtain cores from the areas to be recycled. The contractor shall provide at a minimum, one core for each 500 feet-lane and additional cores at each location where visual differences in the pavement are noticed. If cores show significant differences in material type or thickness of layers, then separate mix designs shall be performed for each area.

C. The mix design shall meet the criteria outlined in Table below. The Contractor shall submit the mix design for approval by the Engineer at least three weeks prior to CIP construction.

Mix Design Requirements

4-inch specimens shall be prepared in a Superpave Gyratory compactor. The mixture should meet the following criteria at the selected design asphalt emulsion content:

Property	Criteria
Compaction effort, Superpave Gyratory Compactor	2 1.25° angle, 12,500 lbs/ft stress, 30 gyrations
Density, ASTM D 2726 or equivalent	Report

Gradation for Design Millings, ASTM C117

Marshall stability*, ASTM D 1559 Part 5, 40°C	1,250 lb min
Retained stability based on cured stability **	70 percent min
Raveling Test, ASTM D 7196-06, 4 hour cure time @ 50 degrees F, @ 50 percent humidity, for 15 minute test time	2 percent max

* Cured stability tested on compacted specimens after 140 degrees F curing to constant weight.

**Vacuum saturation of 55 to 75 percent, water bath 77 degrees F 23 hours, last hour at 104 degrees F water bath

E. The Contractor shall submit with the mix design the supporting data and test results used to produce the mix design.

F. Recycling shall be in a manner that does not disturb the underlying material in the existing roadway.

G. The pulverized bituminous material shall be processed by screening and crushing to the required gradation. The recycled material shall be produced through a mixing unit or chamber capable of processing the pulverized material, asphalt emulsion, and water to a homogeneous mixture.

H. The asphalt emulsion and water shall be incorporated into the pulverized bituminous material at the initial rate determined by the mix design(s) and approved by the Engineer.

I. Sampling and mix design may determine different amounts of asphalt emulsion are required at various portions of the project.

J. The cold in-place recycled asphalt treated base shall be compacted to a density approved by the Engineer.

K. The contractor shall apply a fog seal to all areas as directed by the Engineer prior to opening the lane to uncontrolled public traffic.

PART 3 - EXECUTION

3.1 EQUIPMENT

A. Equipment and facilities for storage, measuring, mixing, heating, transporting, spreading, compacting, and other operations shall be in accordance with the applicable requirements of the governing standards. Improved or modernized equipment which will produce results equal in quality to those which would result from the specified equipment will be considered for use. All equipment and facilities shall be acceptable to the ENGINEER.

3.2 EXCAVATION AND BACKFILL

A. Excavation and backfill are specified in Section 02200, Earthwork.

3.3 PREPARATION OF SUBGRADE

A. Subgrade shall be shaped and compacted in accordance with SSPWC Subsections

300-4.7 to 95 percent relative density.

B. Use of the prepared subgrade for hauling will not be permitted. The CONTRACTOR

shall protect the prepared subgrade from all traffic.

C. The subgrade shall be maintained in the finished condition until the first succeeding course is placed.

D. Unless specified otherwise on the Contract Documents, the upper 30 inches of subbase, the Street Zone, shall be compacted to not less than 95 percent relative density. Compaction operations shall be in conformance with Section 02200, Earthwork.

3.4 BASE COURSE

A. Place crushed aggregate base in a uniform layer over the entire area to receive base course, without segregation of size, to such loose depth that when compacted with the power roller, the course shall have the required thickness shown on the Drawings. Compact over the full width until a density of 95 percent as determined by AASHTO T

180 is obtained. Blade the base with a grader and roll, while damp, with the power roller specified above until the course is thoroughly and uniformly compacted and its surface is smooth and conforms to the grade requirements specified. Maintain the surface in its finished condition until the succeeding layer is placed.

3.5 WEED KILLER

A. After the subbase has been prepared, weed killer shall be applied to the entire base. The weed killer shall be applied according to the manufacturer's published instructions.

3.6 PRIME COAT

A. Prime coat is required in this Contract.

B. After treatment with weed killer, the aggregate base course shall be primed prior to application of the asphalt concrete in accordance with SSPWC, Subsection 302-5.3.

C. The prime coat shall be applied only when the base course surface is dry or slightly damp. For extremely dry areas, a light application of water may be required prior to application of the prime coat which will permit uniform distribution and the desired penetration. The prime coat shall not be applied when the ambient atmospheric temperature is below 60 degrees F.

D. The prime coat shall be applied at a temperature of 175 degrees F to 225 degrees F, and at a rate of 0.3 to 0.4 gallons per square yard.

E. Following the application of the prime coat material, the surface shall be allowed to dry for at least 48 hours without being disturbed, or for an additional period of time as may be necessary to attain penetration of the prime material into the base course, and drying out or evaporation of the volatiles in the prime coat material. Traffic shall be kept off the prime coat until it has penetrated the base course and cured. No prime coat drying time limit is imposed on public streets where fast completion is important. The CONTRACTOR shall furnish and spread enough imported sand on all areas that show an excess of bituminous material to effectively blot up and cure excess prime coat material.

F. The primed surface shall be maintained by the CONTRACTOR until the succeeding layer of pavement has been placed. During this interval, the CONTRACTOR shall protect the primed surface against damage and shall repair all broken spots.

3.7 CONSTRUCTION OF ASPHALT CONCRETE PAVEMENT

A. Lay asphalt concrete over the aggregate base in accordance with the SSPWC Section 302-5.5. The method of proportioning, mixing, transporting, laying, processing, rolling the material, and the standards of workmanship shall conform to the applicable requirements of SSPWC Section 302-5, Asphalt Concrete Pavement. At no time shall the coarse aggregate that has segregated from the mix be scattered across the paved mat.

B. A tack coat of emulsified asphalt shall be applied to the first lift of the pavement prior to placing the second lift. Application shall be in conformance with SSPWC Section 302-

5.4.

C. The ENGINEER will examine the base before the paving has begun. The CONTRACTOR will correct any deficiencies before the paving is started. Roll each lift of the asphalt concrete and compact to 95 percent of the density obtained with the California Kneading Compactor per California Test 304. The grade, line, and cross section of the finished surface shall conform to the Drawings.

D. Asphalt concrete pavement shall consist of one or more courses of a mixture of paving asphalt and graded aggregate placed upon a roadbed or base, or over existing pavement, as indicated on the Contract Documents. The mixture shall be placed when it is at a temperature of not less than 250 degrees F or more than 320 degrees F and shall not be placed onto a wet surface or when the ambient atmospheric temperature is less than 40 degrees F. All paving or resurfacing shall match the appearance of the existing improvements. A 4-inch asphalt concrete course shall be placed over an 11-inch aggregate base course unless otherwise shown on the Contract Documents.

E. When asphalt is to be applied over existing pavement, and local irregularities in the existing surface would result in a course of more than the specified thickness, the surface of the existing pavement shall be brought to uniform contour by patching with asphalt concrete thoroughly tamped or rolled until it conforms with the surrounding surface, and a tack coat applied to the entire surface. Any existing base, surfacing or pavement shall be thoroughly cleaned immediately prior to receiving the plant-mixed surfacing material.

F. Finished pavement, when ready for acceptance, thoroughly compacted and true to cross section, shall not deviate from the designated grade by more than 1/8 inch in 10 feet and shall be free from ruts, depressions and irregularities. The pavement shall be brought to the final grade with a paving machine. The resulting edge of contact between the new and existing pavement shall be a straight, vertical and neat join line parallel to the trench on each side. New pavement shall not lap over the existing pavement.

G. The base asphalt course mixture shall be placed on the prepared subgrade by means of approved spreading devices in accordance with SSPWC, Subsection 302-5.5. Where the finished paving area exceeds 5000 square feet or 9 feet in width, the CONTRACTOR shall use only a Finisher type paving machine. For smaller areas, the motor grader method for placing the base course may be used unless city permits make the Barber-Green method mandatory.

H. The final asphalt concrete course surface shall be 1-inch thick with 1/2 inch maximum aggregate grading. Placing of the final asphalt concrete course shall be done with a Barber-Green type paving machine.

I. Rolling equipment shall conform to the provisions of SSPWC, Subsection 302-5.6.

3.8 PAVEMENT REMOVAL

A. Pavement removal shall be in accordance with SSPWC Subsection 300-1.3 unless otherwise specified herein.

B. Street pavement or pavement within the treatment plants shall be removed within the limits of all construction excavations prior to excavation. Surplus material shall be removed as specified in Section 02200, Earthwork.

C. Prior to removing existing surfacing, pavement cuts shall be made as shown on the Contract Documents and as specified herein. All pavement cuts shall be neat and straight along both sides of the trench or excavation and parallel to its alignment. The strip of existing AC pavement between an excavation and a gutter face or edge of pavement shall be removed and replaced if less than 3 feet in width. Where large irregular surfaces are removed, such trimming or cutting shall be parallel to the roadway centerline or at right angles to the same.

D. After backfilling and compaction, final pavement cuts shall be made by saw cutting (unless permit requirements supersede) to a minimum depth of 2 inches at a point not less than 12 inches outside the limits of excavation.

E. Concrete curbs, cross gutters, sidewalks and driveways shall be saw cut to a minimum depth of 1 1/2 inches and at a point not less than 12 inches outside the limits of the excavation.

3.9 TACK COAT

A. All vertical or horizontal hard surfaces, which will be in contact with new pavement, shall be tack coated in accordance with SSPWC, Subsection 302-5.4, and at an approximate rate of 0.05 to 0.10 gallon per square yard.

3.10 SEAL COAT

A. The entire asphalt concrete pavement shall be fog sealed with asphalt emulsion prior to final striping. The fog sealer shall be applied within 5 calendar days after final asphalt concrete course, at a temperature of 75 degrees F to 130 degrees F, and at a rate of

0.05 to 0.10 gallons per square yard.

B. Seal coat shall extend over the full width of access road unless otherwise specified.

3.11 EMULSION-AGGREGATE SLURRY

A. Emulsion-aggregate slurry shall be applied in accordance with SSPWC Subsection

302-4.

3.12 PAVING HEADERS

A. All edges of paving adjacent to earth shall be bounded by 2- x 6-inch net, new rough- sawn redwood headers staked with 2- x 2- x 18-inch redwood stakes, 4 feet on centers. The top edge of headers shall be at the grade of the proposed asphalt surface. The top of stakes shall be 1-inch below the top of the header.

3.13 ASPHALT CURBS

A. Asphalt curbs, where shown on the Contract Documents, shall be constructed with an automatic curbing machine.

3.14 REPAIRS

A. Areas of new or existing asphalt concrete requiring repair shall be delineated by saw cutting and the asphalt concrete removed, then prime or tack coated, and paved with hot asphalt as specified herein.

3.15 TEMPORARY PAVING

A. Temporary pavement shall be maintained so that a smooth traversable surface free from ruts, depressions, holes and loose gravel is available at all times for vehicular traffic.

3.16 ASPHALLT CONCRETE OVERLAY

A. The CONTRACTOR shall submit the mix design for review by the ENGINEER prior to scheduling the construction of the overlay. The overlay construction shall start after all the construction work in the roads to be overlaid is complete and accepted by the ENGINEER.

B. The contractor will close the road to be overlaid for the duration of the pavement replacement is being placed, compacted, sealed and set for at least two hours.

3.17 CLEANUP

A. Clean all debris and unused materials from the paving operation. Clean all surfaces that have been spattered or defaced as a result of the paving operation. Asphalt or asphalt stains which are noticeable upon surfaces of concrete or materials which will be exposed to view shall be promptly and completely removed. Cleaning shall be done in a manner that will not result in the discharge of contaminated materials into any catch basin or storm drain system.