DPWH_Blue_Book-pages

Payment and Measurement of Bituminous Materials

Payment Under Specific Items

  • Payment will be made under the following pay item numbers:

    • 305 Bituminous Penetration Macadam Pavement

      • 305 (1) Aggregates (Tonne)

      • 305 (2) Asphalt Cement (Tonne)

      • 305 (3) RC Cut-back Asphalt (Tonne)

      • 305 (4) Emulsified Asphalt (Tonne)

    • 306 Bituminous Road Mix Surface Course

Description of BITUMINOUS ROAD MIX SURFACE COURSE

  • Consists of constructing a bituminous road mix surface course on a prepared base.

  • Must conform to lines, grades, and cross-sections from plans or as directed by the Engineer.

Material Requirements

Bituminous Material

  • Types include Rapid Curing (RC) Cut-back, Medium Curing (MC) Cut-back, or Emulsified Asphalt.

  • Must comply with specifications outlined in Item 702, Bituminous Material.

Aggregate

  • Must conform to Item 703, Aggregates.

  • Tested for acceptance before adding bituminous material; can be new or salvaged.

Proportioning of Mixture

  • Percentage of bituminous material should be:

    • 4.5 to 7.0 mass percent for cut-back asphalt.

    • 6.0 to 10.0 mass percent for emulsified asphalt.

  • Must be determined by the Engineer.

  • Hydrated lime should be added during mixing (0.5 to 1.0 mass percent).

Construction Requirements

Weather Limitations

  • Construction should be carried out on dry surfaces, avoiding fog or rain.

Construction Equipment

  • Includes mixing, spreading, finishing, and compacting equipment; a bituminous distributor is necessary with specifications for temperature control and distribution rate.

  • Rollers must weigh at least 8 tonnes, either steel-wheel or pneumatic.

Preparation of Base

  1. New Aggregate: Scarify and blade the existing base to the correct grade.

  2. Salvaged Aggregate: Scarify and blend existing material while rolling the foundation.

Placing Aggregates

  • Must be uniformly spread using approved mechanical devices, with sizing corrected before spreading.

  • Moisture content should not exceed 2% unless emulsified asphalt is used.

Application and Mixing of Bituminous Material

  • Bituminous material applied in successive layers, requiring immediate mixing with the aggregate.

  • Care to be taken to prevent contamination and adhere to moisture specifications.

Spreading, Compacting, and Finishing

  • Material spread with a self-propelled grader or mechanical spreader to achieve required thickness.

  • Rolling must ensure uniform texture and density, with procedures outlined to maintain proper compaction.

Method of Measurement

  • Measured by tonnes of accepted materials; moisture weight will be deducted.

Basis of Payment

  • Payment based on contract unit price for materials used, covering all costs of labor, equipment, and incidentals.

Bituminous Plant-Mix Surface Course – General

Description and Requirements

  • Applicable to all types of bituminous plant mix surface courses.

  • Must conform to specific gradation, thickness, and other requirements laid out by the Engineer.

Material Requirements

  • Composition includes aggregates, mineral filler, hydrated lime, and bituminous material.

  • Job-mix formulas must be submitted for approval at least three weeks prior to production.

Proportioning and Quality Control

  • Aggregates must meet specified tolerances; percentage of bitumen set by the Engineer.

  • Mixtures must maintain certain compressive strengths and air voids.

Construction Requirements

Weather Limitations

  • Similar to Road Mix specifications, placement during poor weather is prohibited.

Equipment Requirements

  • Detailed specifications for mixing plants and batching plants must be followed, ensuring accuracy in weighing and proportioning of materials.

  • Safety measures and emergency protocols in place around equipment operation are necessary.