4−38 Specifications:
a.Cold Feed System. The plant shall have an adjustable feed rate control for the salvaged bituminous pavement feeder, as well as for the cold aggregate feeder and the mineral filler feeder.
b.Mixer Unit.
1.The Drum Mix Plant shall utilize a center entry system for recycling purposes.
2.The moisture content of the mixture upon discharge from the mixer shall not exceed 1.5 percent by weight and the mixture shall have a minimum temperature of 280 OF.
c.Automated Blending System.
1.The plant shall have an automated blending system for proportioning virgin aggregate, liquid bitumen, additives as needed, and recycled material.
2.The blending system shall include a hardcopy strip printer; capable of totaling and printing at intervals quantities of virgin aggregate, liquid bitumen, additives as needed, and recycled material. 407.04 METHOD OF MEASUREMENT. "Base Course" and "Binder Course" which have been produced utilizing the Hot Recycle Option will be measured according to Subsection 401.04 of these Specifications. 407.05 BASIS OF PAYMENT. The accepted quantities of "Base Course" and "Binder Course" which have been produced utilizing the Hot Recycle Option will be paid for according to Subsection 401.05 of these Specifications. SECTION 408 CLEANING AND SEALING CRACKS IN BITUMINOUS CONCRETE PAVEMENTS
408.01 DESCRIPTION. This work shall consist of performing all operations and furnishing all
materials, labor, and equipment necessary in connection with the cleaning and sealing of cracks and open joints in bituminous concrete pavements at the locations indicated and as directed by the Engineer, all in accordance with these Specifications. In this specification, the terms “crack” and “open joint” are used synonymously. All cracks shall be designated as follows: • Cracks 1/16-Inch to Less than One Inch in Width; • Cracks One Inch and Over in Width; • Alligator Cracks, which are cracks in any area where the density and/or severity of cracking forms a chicken wire or alligator pattern. 4−39
408.02 Materials.
408.02.1 Sealant. The sealant shall be either one of the following and shall be subject to approval
by the Engineer prior to the start of work.
a.Joint and crack sealant, hot applied, conforming to ASTM D6690 Type II.
b.Fiber reinforced modified asphalt compound consisting of:
1.Modified Asphalt Binder - This shall consist of a blend of neat asphalt cement and crumb rubber, which are chemically bonded to produce a modified asphalt binder that complies with all the requirements of AASHTO MP1a for PG 70-34, with a separation less than 5% (AASHTO PP 5-93, Section 8.3). The modified asphalt binder shall not contain any particles of rubber or elastomeric material when tested in accordance with AASHTO T 44. The viscosity shall not exceed 3 Pa·s at 300 °F. The dynamic shear of the pressure aging vessel residue shall not exceed 5000 kPa at 7oC. The elastic recovery at 4oC (AASHTO T301) shall be not less than 70%. The modification at a minimum shall consist of 5% crumb rubber from tires. The supplier of the modified asphalt binder shall certify the composition and PG grade of the modified asphalt binder.
2.Asphalt Cement - The high temperature grade (AASHTO MP1a) of the neat asphalt cement shall not exceed PG 58-XX.
3.Crumb Rubber – The modified asphalt binder shall have a crumb rubber content of not less than 5% by weight of neat asphalt cement. The maximum size of the crumb rubber shall be 80 mesh.
4.Chemical Bonding Agent – The chemical bonding agent shall be heat stable and compatible with asphalt and rubber.
5.Fibers - Polyester, fully drawn. Length 10 mm (max) Denier 15 dpf (max) Tenacity 4 gpd (min) Crimp none Color natural Fiber Reinforced Modified Asphalt Compound Properties: Fiber concentration 8% by weight of modified asphalt binder; uniform dispersion of fibers Elongation 8% at 0°F (max) Tensile Strength 450 psi at 0°F (min) Blending of the fibers with the modified asphalt binder shall be in accordance with the recommendations of the manufacturer of the fibers.
408.02.2 Filler. Filler shall consist of Bituminous Concrete Class I-2 or High Performance
Bituminous Cold Patch. The crack filler shall be compatible with the crack sealer and be pre-approved by the Engineer.
408.02.3 Blotter Material. Blotter Material shall be black beauty.
Source: Rhode Island Standard Specifications (Bluebook), 2024 Edition. Pages 216–217 of 826.