02610.00 1132 Aggregates
Description
02610.00Scope - This Section includes the requirements for special filter material for backfilling or
filling trenches for perforated drains and other subsurface drains.
Materials
02610.10Special Filter Materials - Furnish a specially graded filter Material of coarse Sand, and
crushed or uncrushed Rock that meets the following requirements:
(a)Grading - Sieve analysis shall be determined according to AASHTO T 27. The Material shall
meet the following gradation requirements:
Sieve Size Percent Passing (by Weight)
3/8" 100 No. 4 54 - 82 No. 10 34 - 56 No. 40 9 - 17 No. 100 0 - 3
(b)Sand Equivalent - Special filter material shall be tested according to AASHTO T 176 and shall
have a Sand equivalent of not less than 25.
Source: Oregon Standard Specifications for Construction, 2024 Edition. Pages 1198–1198 of 1,268.