4126.01DESCRIPTION
Crushed stone. For non-Interstate mixes steel slag may also be used.
4126.02GRADATION
For quartzite, granite, and slag meet requirements for Gradation No. 37 of the Aggregate Gradation Table, Article 4109.02. For limestone and dolomite meet requirements for Gradation No. 38 of the Aggregate Gradation Table, Article 4109.02
4126.03QUALITY
Meet requirements of Table 4126.03-1 and 4126.03-2 with the exception that use of Friction Type 2 crushed stone requires a maximum abrasion loss of 30% and sand
Aggregate for Flexible Paving Mixtures
4127.02
equivalence of not less than 60. Testing is based on aggregate crushed to 3/4 inch nominal size.
Aggregate Quality
Table 4126.03-1: Aggregate Quality Maximum Percent Test Method Allowed
Abrasion
AASHTO T 96
A Freeze
Office of Materials Test Method No. Iowa 211, Method A
Alumina(a, b)
0.7
Office of Materials Test Method No. Iowa 222
Sand Equivalence
45 (Minimum)
Organic Materials
0.01
(a)
(b)
AASHTO T 176 Office of Materials Test Method No. Iowa 215
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.
Table 4126.03-02: Maximum Permissible Amounts of Objectionable Material Maximum Objectionable Materials Test Method Percent Allowed Unsound chert particles retained on No. 4 sieve
0.5
Materials I.M. 372
Total of all unsound chert, shale, coal, and iron combined
1.0
Materials I.M. 372
Clay Lumps/Friable Particles
0.5
Materials I.M. 368
Organic Materials, except coal
0.1
Iowa DOT Materials Laboratory Test Method No. 215