4132.01DESCRIPTION
• Crushed stone, crushed PCC, crushed composite pavement, or reclaimed HMA, • Mixtures of gravel, sand, and soil, or • Uniformly blended combinations of the above. • Do not place Reclaimed HMA below high water table.
4132.02GRADATION
Meet the gradations of Tables 4132.02-1 and 4132.02-2:
Granular Backfill Material
4133.03
Table 4132.02-1: Gradation Requirements for Special Backfill Material Gradation (Aggregate Gradation Material Table, Article 4109.02) Crushed Stone Crushed PCC Crushed Composite Pavement
No. 30
Gravel or Gravel Blends with Crushed Stone, PCC or Composite
No. 31
Table 4132.02-2: Gradation Requirements for Reclaimed HMA Used for Special Backfill Material Material Gradation Reclaimed HMA
Nominal top size of 2 inches
4132.03QUALITY
For gravel mixture, comply with the following: A.
Plasticity Index. Not to exceed 10%. Test according to Iowa DOT Materials Laboratory Test Method No. 109.
B.
Carbon Content. Not to exceed 1.0%. Test according to Iowa DOT Materials Laboratory Test Method No. 111.
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