Section 4132. Special Backfill Material.

4132.01 DESCRIPTION.

• Crushed stone, crushed PCC, crushed composite pavement, or reclaimed HMA,
• Mixtures of gravel, sand, and soil, or
• Uniformly blended combinations of the above.

4132.02 GRADATION.
Meet the following gradations:

TABLE 4132.02 - 1
Material	Gradation (Aggregate Gradation Table, Article 4109.02)
Crushed Stone Crushed PCC Crushed Composite Pavement	#30
Gravel or Gravel Blends with Crushed Stone, PCC or Composite	#31




TABLE 4132.02 - 2
Material	Gradation
Reclaimed HMA	Nominal top size of 2 inches (50 mm)

4132.03 QUALITY.
For gravel mixture do not exceed the following:

TABLE 4132.03
Maximum Permissible Amounts of Objectionable Materials	Maximum Percent Allowed	Test Method
Plasticity Index	10	Iowa DOT Materials Laboratory Test Method 109
Carbon	1.0	Iowa DOT Materials Laboratory Test Method 111