4121.01DESCRIPTION
Aggregate of the following types: • Crushed stone, • Gravels of which 30% or more of the particles retained on the 3/8 inch sieve have at least one fractured face as defined in Materials I.M. 305, • Crushed PCC pavement meeting the requirements of Materials I.M. 210, or • Uniformly blended combinations of these materials. 4121.02
GRADATION.
A.
Crushed material: meet the requirements for Gradation No. 12a of the Aggregate Gradation Table, Article 4109.02.
B.
Gravel: meet the requirements for Gradation No. 12b of the Aggregate Gradation Table, Article 4109.02.
4121.03QUALITY
The requirements of Table 4121.03-1 apply to the individual virgin aggregates before combining: Table 4121.03-1: Coarse Aggregate Quality (Virgin Material) Coarse Aggregate Quality
Maximum Percent Allowed
Test Method
Abrasion
50
AASHTO T 96
Alumina(a, b)
1.5
Iowa DOT Materials Laboratory Test Method No. 222
A Freeze
Iowa DOT Materials Laboratory Test Method No. 211, Method A
(a)
(b)
If the Alumina value passes, the A-Freeze is not needed for specification compliance. If the Alumina value fails, determine the A Freeze value for specification compliance. Alumina does not apply to gravel.
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