Section 704 — Soil

704.01Soil and Soil-aggregate M aterials. Provide suitable materials conforming to Table 704-1. Table 704-1 Soil Gradation and Classification Requirements

Gradation and

Classification

Requirements Material Designation

Foundation

Fill Bedding

Material Common

Backfill RSS

Backfill Plastic

Pipe

Backfill Structural

Backfill Unclassified

Borrow

Maximum

particle size , in 2 ½ 3 1½ 3 24

Soil

classification , AASHTO M 145 A-1-a – A-1 A-2 A-3 A-1 A-2-4 A-2-5 A-3 – A-1 A-3 A-2-4

Material passing

No. 200 sieve, AASHTO T 27 & T 11 6.0 maximum 10 maximum – – 5.0 maximum –

Plasticity index,

AASHTO T 90 – – – – 6 maximum –

Other

Requirements – – Well - graded Well -graded – –

704.02Select Borrow . Provide a suitable, well -graded material conforming to the following:

(a)Gradation Table 704-2

(b)Liquid limit, AASHTO T 89, Method A 30 maximum Table 704-2

Select Borrow Gradation

Sieve Size Percent by Mass Passing

Designated Sieve

(AASHTO T 27 & T 11) 3 in 100 1 in 70 to 100 No. 4 30 to 70 No. 200 0.0 to 5.0

704.03Select Granular Backfill.

(a)General. Provide suitable, sound, durable, granular material conforming to the following:

(1)Gradation Table 704-3

(2)Angle of internal friction on the portion passing the No. 10 sieve, AASHTO T 236 34 degree minimum AASHTO T 236 is not required for material with more than 40 percent retained on the No. 4 sieve. If required, compact samples to 95 percent of the maximum density at +/ -2 percent of the optimum moisture content determined according to AASHTO T 99, method A or B without oversized material corrections. Perform testing at confining stresses of 1, 2, 4, and 8 kips per square foot.

(3)Soundness of aggregate using sodium sulfate, AASHTO T 104 (5 cycles) 15 percent loss maximum

(4)Plasticity index, AASHTO T 90 6 maximum

(5)Los A ngeles abrasion, AASHTO T 96 50 percent maximum Table 704-3

Select Granular Backfill Gradation

Sieve Size Percent by Mass Passing Designated Sieve (AASHTO T 27 & T 11)

Backfill with Geosynthetic

Reinforcement Backfill with Metallic Reinforcement 4 in – 100 1½ in 100 – No. 40 0 to 60 0 to 60 No. 200 0.0 to 15.0 0.0 to 15.0

(b)MSE walls with metallic reinforcements. Conform to Subsection 704.03(a) and the following:

(1)Resistivity, AASHTO T 288 3000 Ω centimeter minimum

(2)pH, AASHTO T 289 5.0 to 10.0

(3)Sulfate content, AASHTO T 290 200 ppm maximum

(4)Chloride content, AASHTO T 291 100 ppm maximum Tests for sulfate and chloride content are not required if resistivity is greater than 5000 ohm centimeters.

(c)MSE wa lls with geosynthetic reinforcements. Conform to Subsections 704.03(a) and 704.03(b)(2) .