Section 4133.  Granular Backfill Material

 

4133.01     DESCRIPTION.

Crushed stone or natural sand and gravel. If approved by the Engineer, manufactured sand may be substituted in applications where drainage is not a purpose for use of the granular material.

 

4133.02     GRADATION.

Meet the requirements for Gradation No. 32 of the Aggregate Gradation Table, Article 4109.02, except when used as backfill material under flowable mortar or as floodable backfill material.

 

4133.03     QUALITY.

For crushed stone, meet the requirements of Table 4133.03-1:

 

Table 4133.03-1: Aggregate Quality (Granular Backfill Material)

Coarse Aggregate Quality

Maximum Percent Allowed

Test Method

Abrasion

55

AASHTO T 96

C Freeze

20

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

Total of Abrasion & C Freeze

65

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Clay Lumps and Friable Particles

4

Materials I.M. 368

 

4133.04     BACKFILL material UNDER FLOWABLE MORTAR.

Use one of the following:

 

A.    Natural sand complying with the requirements for Gradation No. 1 of the Aggregate Gradation Table, Article 4109.02, with a maximum of 4% passing the No. 200 sieve.

 

B.    Porous Backfill Material complying with Section 4131.

 

C.    Floodable Backfill Material complying with Section 4134.

 

D.   Granular Subbase Material complying with Section 4121.