4122.01 DESCRIPTION.
Crushed stone meeting the following requirements:

4122.02 GRADATION.
Produce Macadam Crushed Stone with a nominal maximum size of 3 inches (75 mm). Screen over a 3/4 inch (19mm) screen, or when specified in the contract documents, a 1 inch (25mm) screen. This is identified as Gradation No. 13 of the Aggregate Gradation Table, Article 4109.02.

The aggregate passing the 3/4 inch (19mm) or 1 inch (25 mm) screen may be furnished as the Choke Stone material; however 6% to 16% of the material must pass the No. 200 (75 μm) sieve.

4122.03 QUALITY.
For Macadam Stone Base and Choke Stone, meet the following requirements as detailed in Section 4109 when crushed to a 3/4 inch (19 mm) or 1 inch (25 mm) nominal size for testing:

TABLE 4122.03 - 1
Macadam Quality	Maximum Percent Allowed	Test Method
Abrasion	50	AASHTO T 96
C Freeze	10	Iowa DOT Materials Laboratory Test Method 211, Method C

Choke Stone that is a byproduct of the Macadam production need not be tested. For Choke Stone that is not a byproduct of Macadam production, meet the following requirements:

TABLE 4122.03 - 2
Choke Stone Quality	Maximum Percent Allowed	Test Method
Abrasion	45	AASHTO T 96
C Freeze	15	Iowa DOT Materials Laboratory Test Method 211, Method C