716Embankment and Subgrade Material

716.1-GENERAL: Material for embankment shall be: random material, rock, hard shale, or borrow material. Material for subgrade shall be granular material. 716.1.1-Random Material: Random material shall be considered as a mixture of any or all of soil, granular material, or soft shale as described which are permitted by the Engineer to be used in embankment. These are materials that can be incorporated in a six ( 6) inch compacted layer. 716.1.1.1-Soil: Soil material shall be considered as layers or deposits of disintegrated rock, lying on or near the surface of the earth; which has resulted from natural processes, such as weathering, decay or chemical action or a combination of these processes. Material shall be considered as soil when more than 25 percent (25%) by weight of the grains or particles pass the No. 200 sieve. 716.1.1.2-Granular Material: Granular material shall be considered as natural or synthetic mineral aggregate, such as broken or crushed rock, gravel, sand, or slag. Shale or fly ash shall not be considered granular material. Granular material shall have not more than 25 percent (25%) by weight of grains or particles passing the No. 200 sieve (determined by AASHTO T-11 and AASHTO T-27) and the plasticity index shall not be more than 6 (determined by AASHTO T -90). The plasticity index shall be determined using a separate unwashed portion of the field sample. Granular material shall not contain particles larger than three (3) inches, by visual inspection. 716.1.1.3-Soft Shale: Soft shale shall be considered as any of the shales, weak sandstone, weak limestone, claystones or silts tones that break down using the following roller test. Rock which breaks down under three complete coverages with a steel drum roller, meeting the following requirement, shall be classified as soft shale to be placed as specified in subsection 207.7.3.2.1. Smooth drum rollers shall provide a minimum 1.5 tons per linear foot of roller width and drum rollers with any type of feet (sheep’s foot, tamping foot, etc.) shall provide the same minimum of 1.5 tons per linear foot of roller drum width. This criteria applies to single and multiple drum rollers as well as vibratory rollers with the vibration set to maximum. This criteria shall be calculated for each roller and test combination by dividing the operating weight of the roller in tons by the total measured width of the drum in feet, or the total of all drums if more than one drum. This calculation shall be provided to the Engineer in writing prior to the test. The contractor shall provide the roller or rollers and any other necessary equipment for this test without additional compensation. 716.1.2-Rock: Rock is defined as sandstone, limestone, or concrete that cannot be incorporated in a six (6) inch compacted lift and shall be medium hard or harder. 716.1.3-Hard Shale: Material that meets the description of shale in subsection 716.1.1.3 except that is does not break down under the hardness test shall be considered as hard shale and placed as specified in subsection 207.7.3.2.2 when used as embankment material. 959 716.1.4-Borrow Material: Borrow shall consist of approved material required for the construction of embankments and other portions of the work and shall be subject to the applicable provisions of 211. 716.2-TEST METHODS: Plastic Limit AASHTO T 90 or ASTM D424 Grain Size Analysis AASHTO T 88 or ASTM D422 Sieve analysis of fine and coarse aggregate AASHTO T 27 Amount of material finer than 200 sieve (0.075 mm) in aggregate AASHTO T 11 Specific Gravity of Soils AASHTO T 100 or ASTM D854 Specific Gravity and Absorption of Coarse Aggregate AASHTO T 85 or ASTM C127 Organic Content AASHTO T 267 Moisture and density of soil and material having less than 40 percent (40%) of particles by weight retained on the ¾ inch (19 mm) sieve MP 207.07.20 Moisture and density of material having 40 percent (40%) or more of the particles by weight retained on the ¾ inch (19 mm) sieve and that are relatively uniform in gradation and can be incorporated in a 12- inch (300 mm) lift or less, and granular subgrade MP 700.00.24 (See MP 717.04.21, Table B) Reclaimed asphalt pavement can be incorporated in a 6-inch (150 mm) lift or less, in subgrade MP 700.00.24 MP 717.04.21, Table B) Liquid Limit AASHTO T 89 or ASTM D423 716.3-MOISTURE AND DENSITY REQUIREMENTS: 716.3.1-Embankment Moisture: Embankment soil and material having less than 40 percent (40%) by weight of particles retained on the ¾ inch (19 mm) sieve shall be moistened or dried to a tolerance of plus three percentage points or minus four percentage points from optimum at the time compactive effort is applied. However, soils which evidence pronounced elasticity as the result of compactive effort shall be dried to optimum moisture content, if necessary to achieve stability. 716.3.2-Embankment and Subgrade Density: 716.3.2.1-Soil and material having less than 40 percent (40%) by weight of particles retained on the ¾ inch (19 mm) sieve shall be compacted within the moisture tolerance to a target percentage of dry density (Note 1) specified in Table 716.3.2.2. The maximum required dry density and the in -place dry density of the soil layers placed and compacted shall be determined by MP 207.07.20. 716.3.2.2- Soil and material having 40 percent (40%) or more by weight of particles 960 retained on the ¾ inch (19 mm) sieve that are relatively uniform in gradation and can be incorporated in a twelve (12) inch lift or less, shall be compacted to the target percentage of dry density (Note 1) specified in Table 716.3.2.2. The maximum required dry density shall be determined by Part 1 of MP 700.00.24. The in -place dry density of the soil layers placed and compacted shall be determined in accordance with Part II of MP 700.00.24. TABLE 716.3.2.2 Type of Construction Target % of Dry Density (Note 1) Target % of Dry Density (Note 1) of Material Having Less Than of Material Having 40% or 40% by Weight Retained on More By Weight Retained on mm) the ¾ in. (19 mm) Sieve the ¾ in.(19 mm) Sieve and Granular Subgrade Embankment 95 95 Subgrade 95 95 Note 1-Target percentage of density shall be the percentage of density by which the decision of acceptance is based. The percentage of dry density for each test shall be determined by comparing the in- place dry density with required maximum dry density. 716.3.2.3-Material, as outlined in MP 717.04.21, TableB, shall be proof rolled with a pneumatic tire roller having an effective weight of 50 tons. Alternate proof rollers, acceptable to the Engineer, may be used in lieu of a 50 -ton pneumatic tired roller provided the weight per tire and tire pressure is maintained so that a mi nimum of 1315 pounds per inch width of tire is maintained. The roller shall be operated at a speed of not more than five miles per hour. The designated areas to be proof rolled shall have two or more passes and the entire area shall be systematically covered with the proof rolling. During the proof rolling and after the proof rolling is completed, the area shall be checked for unstable areas or soft spots disclosed by the operation of the proof roller. These unstable areas or soft spots shall be corrected prior to placement of the overlying lifts of material. The Contractor may propose an alternate approach for small areas that are impractical to roll with the proof roller. 716.4-EMBANKMENT ORGANIC CONTENT: The organic content of the embankment material shall not exceed 7.5 percent (7.5%) by weight as determined by AASHTO T 267. 716.5-ACCEPTANCE OF EMBANKMENT AND SUBGRADE: The density of the embankment and subgrade will be accepted by the Division on a lot to lot basis provided the lot conforms to the specifications. A lot shall contain five approximately equal sublots. A sublot shall consist of not more than 2,500 cu. yd. for embankment and 400 linear feet per working width for subgrade. The Contractor's quality control testing shall include one nuclear moisture and density measurement made at a random location within each of the sublots. Each lot shall be presented to the Engineer for acceptance. When a lot consists of more than one lift, the Contractor's quality control testing shall normally include testing on each lift. Testing for density shall be in accordance with subsections 716.3.2.1, or 716.3.2.2, whichever is applicable. The random locations shall be determined in accordance with MP 712.21.26. The Contractor's 961 quality control testing will be evaluated for each lot and acceptance of the lot may be based either upon the Contractor's quality control testing or by independent testing performed by the Division. The acceptance decision will be made as soon as practicable after the Contractor has informed the Engineer that the lot is ready for acceptance. If the results of density tests on a lot indicate that at least 80 percent (80%) of the material, in accordance with 106.3.1 (West Virginia APA), has been compacted to the specified target percentage of dry density, the lot will be accepted. If less than 80 percen t (80%) of the material has been compacted to the specified target percentage of dry density, no additional material shall be placed on the lot until it has been reworked to meet the specified requirements. Lots failing to meet the quality requirements sh all be reworked by the Contractor at their expense and be resubmitted for acceptance. Evaluation of the reworked lots, when the testing is performed by the Division, shall be at the expense of the Contractor at the unit cost specified in subsection 109.2.2. The quality requirements of this Subsection shall apply to the reworked lots. 962