4124.01DESCRIPTION
Crushed stone.
4124.02GRADATION
Meet the requirements for Gradation No. 22 or No. 23 (as specified in the contract documents) of the Aggregate Gradation Table, Article 4109.02.
4124.03QUALITY
Type 4 or better friction classification aggregate as shown in Materials I.M. T203. Meet the requirements of Table 4124.03-1 based on aggregate crushed to 3/4 inch nominal size. Alumina d oes not apply to gravel.
Table 4124.03-1: Aggregate Quality (Slurry Mixtures) Maximum Percent Aggregate Quality Test Method Allowed Abrasion AASHTO T 96 A Freeze
Iowa DOT Materials Laboratory Test Method No. 211, Method A
Alumina(a, b)
0.7
Iowa DOT Materials Laboratory Test Method No. 222
Sand Equivalence
45 (Minimum)
Organic Materials
0.01
(a)
(b)
AASHTO T 176 Iowa DOT Materials Laboratory Test Method No. 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.