Section 4131.  Porous Backfill Material

                                                    

4131.01     DESCRIPTION.

Gravel or crushed stone.

 

4131.02     GRADATION.

Meet the requirements of Gradation No. 29 of the Aggregate Gradation Table, Article 4109.02.

 

4131.03     QUALITY.

No visible clay lumps, friable particles, and clay coatings. Meet the requirements of Table 4131.03-1:

 

Table 4131.03-1: Aggregate Quality (Porous Backfill Material)

Aggregate Quality

Maximum Percent Allowed

Test Method

Abrasion

50

AASHTO T 96

Alumina(a)

0.7

Office of Materials Test Method No. Iowa 222

A Freeze

10

Office of Materials Test Method No. Iowa 211, Method A

Shale

5

Materials I.M. 345

(a)   If the Alumina value fails, determine the A Freeze value for specification compliance. Office of Materials Test Method No. Iowa 222 does not apply to gravel.