c.Specification-Section_02630-Base_Aggregate.pdf

02630

Section 02630 - Base Aggregate

Description

02630.00 Scope - This Section includes the requirements for aggregates in base.

Materials

02630.10 Dense-Graded Aggregate:

(a) Grading - Dense-graded base aggregate shall be crushed rock, including sand. Uniformly grade the aggregates from coarse to fine. Sieve analysis shall be determined according to AASHTO T 27. The aggregates shall conform to one of the grading requirements of Table 02630-1 as identified in the Special Provisions or indicated by the pay items in the Contract Schedule of Items.

Table 02630-1 Grading Requirements for Dense-Graded Aggregate

Separated Sizes Sieve Size 2 1/2" - 0 2" - 0 1 1/2" - 0 1" - 0 3/4" - 0 Percent Passing (by Weight) 3" 100 2 1/2" 95 - 100 100 2" – 95 - 100 100 1 1/2" – – 95 - 100 100 1 1/4" 55 - 75 – – – 1" – 55 - 75 – 90 - 100 100 3/4" – – 55 - 75 – 90 - 100 1/2" – – – 55 - 75 – 3/8" – – – – 55 - 75 1/4" 30 - 45 30 - 45 35 - 50 40 - 55 40 - 60 No. 4 1 – – – – – No. 10 2 2 2 2 2

1 Report percent passing sieve when no grading requirements are listed 2 Of the fraction passing the 1/4 inch sieve, 40 percent to 60 percent shall pass the No. 10 sieve

(b) Fracture Of Rounded Rock - Fracture of rounded rock shall be determined according to AASHTO T 335. Provide at least one fractured face based on the following percentage of particles retained on the 1/4 inch sieve for the designated size:

Minimum Percent of Fractured Particles (by Weight of Material)

Designated Size Retained on 1/4 inch Sieve

1 1/2" - 0 and larger 50 Smaller than 1 1/2" - 0 70

02630

(c) Durability - Dense-graded aggregate shall meet the following durability requirements:

Test Test Method Requirements

Abrasion AASHTO T 96 35.0% maximum Degradation (coarse aggregate)

Passing No. 20 sieve ODOT TM 208 30.0% maximum Sediment Height ODOT TM 208 3.0" maximum

(d) Sand Equivalent - Dense-graded aggregate shall be tested according to AASHTO T 176, and shall have a sand equivalent of not less than 30.

02630.11 Open-Graded Aggregate:

(a) Grading - Open-graded aggregate shall conform to the following grading requirements:

Table 02630-2 Aggregate Gradation for Open-Graded Aggregate

Percent Passing Sieve Size (by Weight) 1" 100 3/4" 80 - 98 1/2" 60 - 85 3/8" 30 - 65 No. 10 5 - 20 No. 40 0 - 6 No. 100 0 - 3 (Dry Sieve)

(b) Fracture of Rounded Rock - Fracture of rounded rock shall be determined according to AASHTO T 335. Open-graded aggregate fracture requirements shall conform to the following:

Percentage of Fracture (by Weight) Material Retained on 3/4", 1/2", and 1/4" Sieves (two fractured faces) Material Retained on No. 10 Sieve (one fractured face)

(c) Durability - Open-graded aggregate shall meet the durability requirements of 02630.10(c).