for Highway Construction Page 562 of 71 5 SECTION 641 – BIAXIAL GEOGRID
641.01 Description.
Provide biaxial geogrid and all accessories, equipment, and labor necessary to reinforce subgrade or subbase, or similar applications as specified or as directed.
641.02 Materials.
Provide the geogrid manufacturer’s certified test results attesting the geogrid meets the specifications. Provide geogrid certifications signed by the manufacturer’s authorized agent, including the following information about each geogrid to be used:
1.Manufacturer’s name, address, and phone number.
2.Full product name.
3.Style or product code number.
4.Geogrid roll and/or lot number.
5.Geogrid polymer type.
6.Testing agency name, address, and phone number.
7.Certified te st dates and results.
8.Published physical dimensions. Provide the test dates on the certification. As a means of identification, provide tags on the product rolls with the manufacturer’s name, full product name, style or product code number, and lot and/or roll number, which will permit field determination of the product delivered to the project site is covered by the certification. Ensure the certified copy of the test results includes each test result and each mean average roll value. The Department will not accept the certification without the certified test results. The Engineer will obtain geogrid samples for testing. Each sample will be taken beyond the first wrap and will be at least 6 feet long and extend across the full geogrid roll width. The samples will be labeled with the manufacturer and full product name, style or product code number, lot and roll number, and sampling date.
A.Geogrid Property Requirements . Provide biaxial geogrid and associated components that meet the requirements in Table 641.02- 1. Ensure the biaxial geogrid consists of a regular network of connected longitudinal and transverse polymer elements with aperture geometry sufficient to allow significant mechanical interlock with the surrounding materials. Constr uct in single or multiple layers meeting the requirements in Table 641.02- 1. Table 641.02- 1 Geogrid Property Requirements Minimum Value (a) Property Test Method Type I Type II Type III Tensile Strength @ 5% strain , (lb/ft) ASTM D6637 550 800 1200 Tensile Strength ASTM D6637 275 400 550 for Highway Construction Page 563 of 71 5 Minimum Value (a) Property Test Method Type I Type II Type III @ 2% strain , lb/ft Flexural Rigidity lb-mil (mg -cm) ASTM D7748 215 (250,000) 660 (750,000) 1,730 (2,000,000) Junction Strength, lb ASTM D7737 25 35 45 Aperture Size Range, in ID Caliper 0.8 - 2.0 0.8 - 2.0 0.8 - 2.0 Open Area, % COE CW -02215 70 70 70
a.Minimum Average Roll Values (MARV) in the weakest direction. The geogrid type is shown on the plans. When the geogrid type is not shown, use Type II.
B.Transportation and Handling Requirements. Inspect geogrid deliveries to ensure the proper material is received. During all periods of shipment and storage, do not expose the geogrid to temperatures above 140°F or to any deleterious materials that might adversely affect its performance. Follow the manufacturer’s written instructions regarding storage, h andling, and protection from sunlight. Provide clear identification on every geogrid roll as required above, including product designation identification, manufacturer’s name, lot number, and material quantity that clearly differentiates b etween rolls of different geogrid types.
641.03 Construction Requirements.
Place fill material over the geogrid with low ground pressure (i.e., less than 5 psi) track equipment (e.g., small dozers designed for low ground pressure work). Compact fill mater ial to Class A or as directed. Do not turn track equipment on the first lift of material over areas supported by geogrid. Install geogrid at the locations specified or as directed. Temporarily stretch and secure geogrid in place with staples, pins, sand bags, or backfill as required by fill properties, fill placement procedures, or as directed. Keep the geogrid taut and without wrinkles during t he first fill lift placement. Remove slack in the geogrid a s required by the Engineer. Provide a minimum overlap width of 2 feet or as directed. At transverse joints , install the preceding roll so it overlaps the following roll in the direction that the fill will be placed and spread. Ensure that geogrid sections do not separate at overlaps during fill placement. Cut geogrid placed at corners or curves so there is always a minimum 2 feet overlap. Operate rubber -tired equipment on the geogrid at 5 mph or less and only if the underlying material is capable of supporting the load. Dump and spread the backfill in uniform lifts to maintain the required thickness at all times. Do not spread overlying material closer than 2 feet from geogrid edges before forming overlaps for in stallations requiring adjacent geogrid placements, so that subsequent overlaps can be constructed without having to push material back from geogrid edges. for Highway Construction Page 564 of 71 5 Do not operate track vehicles on the geogrid until there is at least 6 inches of fill material betwe en the geogrid and the tracks. If ruts are created in the fill material due to construction traffic, f ill them with additional fill material. Do not blade adjacent material into the ruts. Repair any geogrid sections that are damaged at no cost to the Department. Ensure all repaired sections contain a minimum 3 feet overlap in all directions .
641.04 Method of Measurement.
The Engineer will measure acceptably completed work by the square yard. A separate measurement will not be made for overlaps.
641.05 Basis of Payment .
The Department will pay for accepted quantities as follows: Pay Item Pay Unit Biaxial Geogrid ....................................................................................... SY 642-644 for Highway Construction Page 565 of 715 SECTIONS 642 -644 - RESERVED for Highway Construction Page 566 of 71 5 SECTION 645 – FIELD LABORATORIES
645.01 Description.
Provide and maintain the specified class of field laboratory at an approved location for the Engineer’s exclusive use for this contract. If the Engineer, or consultant working under the Engineer’s direction, is responsible for damage to the field laboratory or its equipment beyond what is expected during normal use, the Engineer will reimburse the Contractor for the damage at a reasonable replacement or maintenance cost. The Contractor must demonstrate to the Engineer that the damage was beyond normal wear and t ear before the Engineer will reimburse the Contractor for damage.
1.Class I Field Laboratory – Aggregate and Soils.
2.Class II Field Laboratory – Aggregate, Soils, and Superpave HMA SP 2.
3.Class III Field La boratory – Aggregate, Soils, and Superpave HMA SP 3 and SP 5.
4.Class IV Field Laboratory – Superpave HMA SP 3 and SP 5.
645.02 Materials.
A.All Field Laboratories. Provide field laboratories meeting these requirements:
1.Certified in accordance with the Department’s laboratory qualification program.
2.Single trailer, 2 separate trailers, or onsite building.
3.Exterior door(s) meeting applicable requirements for egress. At least 1 door will have a nominal width measuring at least 36 inches.
4.Minimum of 3 exterior windows, not smaller than 3 feet by 3 feet.
5.Weather tight.
6.Lockable windows and doors.
7.Minimum ceiling height of 7 feet 6 inches.
8.Minimum total interior floor space of 192 square feet.
9.Meet all applicable federal and state safety codes.
10.Equipped with adequate ventilation, meeting all manufacturer’s recommendations for the evacuation of fumes created by heating or testing of hot mix asphalt .
11.Hardware necessary to allow the Engineer to secure the field laboratory with Department locks on all doors.
12.Provide electric heating and electric air conditioning, capable of maintaining a room temperature within 5° of 70° F continuously, with lights, furnaces, and ovens operati ng.
13.Steps of nonskid metal, with metal handrails and level landing platform secured to the field laboratory. Maintain and repair field laboratory and all equipment.
Source: Idaho Standard Specifications for Highway Construction, 2023 Edition. Pages 598–601 of 768.