4123Modified Subbase Material

4123.01DESCRIPTION

Aggregate of the following Types: • Crushed stone, • Gravels for which 75% 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, • Recycled pavements meeting Materials I.M. 210, or • Uniformly blended combinations of these materials with a maximum of 50% RAP. • Do not place RAP below high water table. 4123.02

GRADATION.

A.

Meet the requirements for Gradation No. 14 of the Aggregate Gradation Table, Article 4109.02.

B.

Process RAP to pass the 2 inch sieve.

C.

Uncrushed gravel and/or sand may be uniformly blended with crushed recycled pavement or crushed stone at a maximum rate of 50% to meet gradation requirements.

4123.03 A.

QUALITY. The requirements of Table 4123.03-1 apply to virgin materials:

Aggregate for Bituminous Sealcoat

4125.01

Table 4123.03-1: Aggregate Quality Aggregate Quality

Maximum Percent Allowed

Test Method

Abrasion

50

AASHTO T 96

C Freeze

Iowa DOT Materials Laboratory Test Method No. 211, Method C

B.

The requirements of Table 4123.03-1 apply to recycled PCC when the aggregate source is unknown as outlined in Materials I.M. 210.