7-6 Sectio N 703 – Soils and Borro W Materials
703.0 1 CLASSIFICATIO N OF SOILS . Based upon their field performance, soils shall be classified into seven groups that are designated as A -1, A-2, A-3, A-4, A-5, A-6, and A -7. This classification shall be based upon the results of tests made in accordance with AASHTO M 145 , as specified in Table 703.01A . TABLE 703.01A – CLASSIFICATION OF SOILS General Classification Granular Materials Silt-Clay Materials Group Classification A-1-a A-1-b A-3 A-2-4 A-2-5 A-2-6 A-2-7 A-4 A-5 A-6 A-7-5 1 A-7-6 2 Sieve Designation Percentage by Mass (Weight) Passing Square Mesh Sieves No. 10 (2.00 mm) ≤ 50 -- -- -- -- -- -- -- -- -- -- -- No. 40 (0.425 mm) ≤ 30 ≤ 50 ≥ 51 -- -- -- -- -- -- -- -- -- No. 200 (0.075 mm) ≤ 15 ≤ 25 ≤ 10 ≤ 35 ≤ 35 ≤ 35 ≤ 35 ≥ 36 ≥ 36 ≥ 36 ≥ 36 ≥ 36 Property Characteristics of the Fraction Passing the No. 40 (0.425 mm) Sieve Liquid Limit -- -- ≤ 40 ≥ 41 ≤ 40 ≥ 41 ≤ 40 ≥ 41 ≤ 40 ≥ 41 Plasticity Index ≤ 6 NP 3 ≤ 10 ≤ 10 ≥ 11 ≥ 11 ≤ 10 ≤ 10 ≥ 11 ≥ 11 1, 2 Usual Types of Soil Gravel and sand Fine sand Silty or clayey gravel and sand Silty soils Clay soils 1 The plasticity index of the A -7-5 subgroup is equal to or less than the liquid limit minus 30 . 2 The plasticity index of the A -7-6 subgroup is greater than the liquid limit minus 30 . 3 NP = Non-plastic Begin the classification procedure by taking the required data and proceeding from left to right in Table 703.01A . The correct group will be found by the process of elimination. The first group from the left into which the test data will fit is the correct classification. Where the Unified Soil Classification System (USCS) is referenced in the Contract, it shall be based on the soil classification chart in ASTM D2487 .
7-7 703.0 2 EART H BORROW . Earth borrow shall be material of a qualit y approved by the Agency as
meeting the requirements for the particular embankment, backfill, or other use for which the material is intended, and shall show evidence of satisfactory compaction when placed in embankments. The natural moisture content shall be less than the laboratory optimum moisture content as determined in accordance with AASHTO T 99, Method C . 703.0 3 SAND BORRO W AND CUSHION . Sand borrow and cushion shall consist of material reasonably free from silt, lo am, clay, or organic matter and shall meet the requirements of Table 703.03A as determined in accordance with AASHTO T 27 . TABLE 703.03A – GRADATION OF SAND BORROW AND CUSHION Sieve Designation Percentage by Mass (Weight) Passing Square Mesh Sieves 2 inch (50.0 mm) 100 1-1/2 inch (37.5 mm) 90 – 100 1/2 inch (12.5 mm) 70 – 100 No. 4 (4.75 mm) 60 – 100 No. 100 ( 0.150 mm) 0 – 20 No. 200 ( 0.075 mm) 0 – 8 703.0 4 GRANULA R BORROW . Granular borrow shall consist of stone and sand reasonably free from loam, silt, clay, and organic material and shall meet the requirements of Table 703.04A as determined in accordance with AASHTO T 27 . TABLE 703.04A – GRADATION OF GRANULAR BORROW Sieve Designation Percentage by Mass (Weight) Passing Square Mesh Sieves No. 4 (4.75 mm) 20 – 100 No. 200 ( 0.075 mm) 0 – 12 703.0 5 ROCK BORROW . Rock borrow shall consist of blasted rock broken into various sizes that will form a compact embankment with a minimum of voids. The maximum size shall be 36 inches in its widest dimension and that size which may be incorporated in a 24 inch layer of rock embankment.
7-8 Sectio N 704 – Aggregates
704.01 FINE AGGREGATE FOR CONCRETE . Fine aggregate for concrete shall consist of natural sand, manufactured sand, or stone screenings washed in an approved manner or a combination thereof. Fine aggregate shall consist of clean, hard, durable grains, unifo rmly graded from coarse to fine, shall be free from detrimental amounts of organic matter or other harmful substances, and shall be obtained from approved sources.
a.Grading . Fine aggregate for concrete shall meet the gradation requirements of Table 704. 01A as determined in accordance with AASHTO T 27. TABLE 704.01A – GRADATION OF FINE AGGREGATE FOR CONCRETE Sieve Designation Percentage by Mass (Weight) Passing Square Mesh Sieves 3/8 inch (9.50 mm) 100 No. 4 (4.75 mm) 95 – 100 No. 16 (1.18 mm) 50 – 80 No. 30 (0.600 mm) 25 – 60 No. 50 (0.300 m m) 10 – 30 No. 100 (0.150 mm) 2 – 10 The fineness modulus on that portion of material passing the 3/8 inch (9.50 mm) sieve shall be determined by laboratory sieve tests. The fineness modulus is defined as the summation of the percentages of sand retained on the No. 100 (0.150 mm), No. 50 (0.300 mm), No. 30 (0.600 mm), No. 16 (1.18 mm), No. 8 (2.36 mm), and No. 4 (4.75 mm) sieves, divided by 100. The minimum and maximum fineness moduli shall be 2.30 and 3.10, respectively. Fine aggregate from any one source for any one designated mix having a variation in fineness modulus greater than 0.20 from the fineness modulus of a representative sample proposed for use may be rejected.
b.Organic Impurities . Fine aggregate for concrete shall have an organic plate number of two or less as determined in accordance with AASHTO T 21 .
Source: Vermont Standard Specifications for Construction, 2024 Edition. Pages 1158–1159 of 1,380.