Appendix A - Chip Specifications DQ 25-092 GB - Aggregates R2 - 4 Locations.pdf

ATTACHMENT A - STATEWIDE CHIP SPECIFICATIONS

Aggregate for Cover Coat Material: Aggregates for cover coat material shall be crushed stone, crushed gravel, or natural gravel. Aggregates shall be composed of clean, tough, durable fragments free from an excess of flat, elongated, soft, or disintegrated pieces and free from fragments coated with dirt or other objectionable matter.

The aggregate shall conform to the following requirements:

(1) The percentage of wear, Los Angeles Abrasion Test (AASHTO T 96), shall not be more than 35.

(2) Type I, II or IV cover coat material shall have no more than 12 percent flat and elongated particles with a ratio of 3:1 when tested in accordance with ASTM D 4791, Method B, by particle count not sample mass. Calculation shall include weighted average percentages per ASTM D 4791, Section 10.1.5. Particle count shall be defined as a minimum of 125 particles on the 3/8” sieve and 200 particles on the #4 sieve. The test frequency for flat and elongated shall be of 1 per 200 tons of delivered chips, or fraction thereof. Acceptance samples will be taken by CDOT forces at the time(s) and location(s) of delivery.

(3) For Type I or II cover coat material, 90 percent by weight of the particles retained on the 4.75 mm (No. 4) sieve shall have at least one fractured face when tested per Colorado Procedure 45. The test frequency for fractured faces shall be of 1 per 200 tons of delivered chips, or fraction thereof. Acceptance samples will be taken by CDOT forces at the time(s) and location(s) of delivery.

(4) For Type I or II cover coat material will be tested in accordance with CP-31, Method B, for gradation of the extracted aggregate, at a CDOT Materials Lab. The test frequency for gradation shall be of 1 per 200 tons of delivered chips, or fraction thereof. Acceptance samples will be taken by CDOT forces at the time(s) and location(s) of delivery.

(5) Lightweight aggregate used for cover coat material shall be an aggregate prepared by expanding shale, clay, or slate in a rotary fired kiln. Lightweight aggregate shall have a dry loose unit weight of 35 to 55 pounds per cubic foot determined per AASHTO T 19, Shoveling Procedure. The total mass of the test sample of lightweight aggregate used in AASHTO T 96 (Los Angeles Abrasion) shall be 2,000 g.

(6) Contractor shall provide a five (5) day advance notice before delivery commences to a given location to coordinate sample collection with Region material technician. Samples will be taken prior to stockpiling operation immediately after delivery in accordance with Section 4.3.3.3 of the Colorado Procedure 30 in the Field Material Manual.

Table 1

GRADATION SPECIFICATIONS FOR COVER COAT AGGREGATE (CHIPS)

Sieve Size

Percent by Weight Passing Square Mesh Sieve

9.5 mm (3⁄s")

Type 1

12.5 mm (1/2")

Type II

19.0 mm (3/4")

12.5 mm (1/2") 100

9.5 mm (3⁄s") 100 65-85

4.75 mm (#4) 0-15 0-10 75 μm (#200) 0-3 0-3

DQ 25-092 GB - Aggregate R2 - 4 Locations

(7) Section 105 of the Standard Specifications is hereby revised for this project as follows:

In subsection 105.03, delete the eleventh paragraph, including the table of price reduction factors (Table 105-2) and table of the multiplier for price reductions (Table 105-3), and replace with the following:

TABLE OF PRICE REDUCTION FACTORS

Element Factor “F” 100 percent size sieve 1

12.5 mm (½”) sieve and larger 1 150 µm (No. 100) sieve to 9.5 mm (3/8”) sieve inclusive (except 100 percent size sieve)

75 µm (No. 200) sieve 6 75µm (No. 200) sieve (cover coat material) Fractured Faces (cover coat material) Flat and Elongated Particles (cover coat material)

Liquid Limit 3 Plasticity Index 10 Asphalt penetration 1 Asphalt residue 3 Portland Cement Concrete Pavement Fine Aggregate Sand Equivalent

0.3

Hydrated Lime Gradation 0.3 Toughness, inch-pounds, minimum 0.8 Tenacity, inch-pounds, minimum 0.8 Elastic Recovery, 25 °C, percent minimum 1.25 Ductility, 4 °C (5cm/min) cm, minimum 1.25

If the P for aggregate gradation, fractured faces and flat and elongated particles for Item 409 is 3 or greater the reduction will apply to the contract price multiplied by the Multipliers (M) listed in the following table:

MULTIPLIER FOR PRICE REDUCTIONS FOR MISCELLANEOUS ITEMS

Item Number-Name Element Multiplier (M)

409-Cover Coat Gradation, Fractured Faces

0.60 and Flat and Elongated Particles