Section 4131.� Porous Backfill Material

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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.