Section 4124. Aggregate for Slurry Mixtures

 

4124.01 DESCRIPTION.

Crushed stone.

 

4124.02 GRADATION.

Meet the requirements for Gradation No. 22 or No. 23 (as specified in the contract documents) of the Aggregate Gradation Table, Article 4109.02.

 

4124.03 QUALITY.

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.

 

Table 4124.03-1: Aggregate Quality (Slurry Mixtures)

Alumina does not apply to gravel.

Aggregate Quality

Maximum Percent Allowed

Test Method

Abrasion 

40

AASHTO T 96

A Freeze

10

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)

AASHTO T 176

Organic Materials

0.01

Iowa DOT Materials Laboratory Test Method No. 215

(a)     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.

(b)     Alumina does not apply to gravel.