SECTION 430 — BITUMINOUS WEARING COURSE FB-2
430.1 DESCRIPTION —
This work is construction of a wearing course of plant-mixed bituminous concrete on a prepared surface.
430.2 MATERIAL —
Section 401.2, and as follows:
(a) Bituminous Material.
One of the following, at the mixing temperatures shown:
Type of Material
Mixing Temperature, F
Cationic Emulsified Asphalt
Fine Aggregate — Section 703.1
Coarse Aggregate, Type A — Section 703.2
(d) Composition of Mixtures.
Add the following:
When asphalt cement is used, provide a completed bituminous mixture range from 200F to 250F.
430.3 CONSTRUCTION —
Section 401.3, except as follows:
(b) Bituminous Mixing Plant.
1. Plant Requirements.
Equipment for developing the design and control tests, in accordance with the Department's modified Marshall method, is not required.
2. Preparation of Mixture.
Thoroughly coat the aggregate with bituminous material, forming a film of sufficient thickness to provide the required binding properties. Add to the mixture 6% to 12%, by weight, of fine aggregate, within the range directed. Use dry-heated coarse aggregate with asphalt cement. Dry the aggregate, as necessary, when using other bituminous materials, prior to mixing at a temperature not exceeding 110F. Damp aggregate may be used with emulsified asphalt. Heat the bituminous material to the temperatures specified in Section 430.2(a). Mixing-time requirements and requirements for determining the percentage of the aggregate coated, specified in Chapter 1, Bulletin 27, do not apply. Instead, add the required quantities of aggregate and bituminous material to the mixer. Then, unless otherwise specified, mix the material to obtain a uniform coating of particles and a thorough distribution of bituminous material.
(d) Bituminous Pavers.
The requirement for a heated unit does not apply when the bituminous material used is an emulsified asphalt.
(f) Preparation of Existing Surface.
Tack coat requirements apply only when
designated in the contract.
Spreading and Finishing.
When spreading with emulsified asphalt, do not strip asphalt from the aggregate. Do not place the wearing course until the binder course is satisfactorily cured and in no case within 24 hours after placing the binder course. When using asphalt cement, the 24-hour requirement is waived.
After the course has been spread uniformly, allow the mixture to cure, as specified in Section 430.3(g) or until the surface becomes tacky. Compact with a power roller until the mixture is compressed to a firm, even surface. Intermediate rolling with a pneumatic-tire roller is not required.
(i) Density Acceptance.
Density acceptance will be determined based on nonmovement of material under compaction equipment.
(p) Defective Work.
Revise to read:
Unless otherwise directed in writing by the District Engineer, remove and replace pavement deficient in surface tolerance as specified in Section 401.3(k), or deficient in depth as specified in Section 401.3(m), or defective in residual asphalt content as specified in Section 401.2(d).
(q) Verification Samples.
Delete this section.
Delete this section.
430.4 MEASUREMENT AND PAYMENT —
(a) Bituminous Wearing Course
FB-2. Square Yard or Ton
(b) Scratch Course.
(c) Leveling Course.
Most Current Supplement
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