3-30 Section 308. Geosynthetics for Base
308.01 Description
This work consists of providing and installing geosynthetic products on a surface approved by the Engineer.
308.02 Materials
Provide material in accordance with the following sections : Geotextile Separator ............................................................................. 910 Stabilization Geotextile ......................................................................... 910 Road Grade Biaxial Geogrid ................................................................. 910
308.03 Construction
A.Geotextile Placement . Place or install g eotextile separator or stabilization geotextile products in accordance with the manufacturer’s installation guidelines and this subsection. Do not operate equipment that is required to place backfill directly on geotextile products. Eliminate wrinkles or waves that develop during placement. Place the products in direct contact with the soil below before placing backfill on the geotextile products. Do not expose geotextile to ultraviolet degradation for more than 7 days. Shingle- lap longitudinal and transverse joints at least 2 feet or seam the joints in accordance with the manufacturer’s recommendations. Ensure that field or factory seams meet the minimum grab tensile strength for the product application. Do not use nylon thread for geotextile seaming. Place seams faci ng upward for inspection purposes. Repair tears or damage to the geotextile in accordance with the manufacturer’s recommendations.
B.Geogrid Placement . All areas immediately beneath the installation area for the geogrid must be properly prepared as shown on the plans, as specified, or as directed by the Engineer. Place or install the geogrid in accordance with the manufacturer's installation guidelines and this subsection. To prevent undue exposure or damage to the geogrid, place only the amount of geogrid re quired for immediately pending work. Do not expose geogrid to ultraviolet degradation for more than 7 days. The geogrid must be unrolled parallel to the centerline of the roadway. Place the geogrid taut prior to placement of subsequent aggregate layer. Anchor the geogrid in position after placement until placement of the subsequent aggregate layer. Overlap adjacent rolls of geogrid 2 feet minimum. Whenever possible, the placement of the subsequent MDOT Standard Specifications for Construction Section 308 3-31 aggregate layer must proceed from the centerline of the geogrid placed out to assist in tensioning the geogrid. Place at least 6 inches of the subsequent aggregate layer over the geogrid before allowing construction vehicles on the geogrid.
C.Aggregate or Granular Material Placement. Spread and shape the subsequent layer of aggregate or granular material after placing geosynthetic to create a stable work platform before compaction. Place additional aggregate or granular material, as required by applicable sections, and compact. Fill ruts with additional ag gregate or granular material and compact before placing each subsequent layer.
308.04 Measurement and Payment
Pay Item Pay Unit Geotextile, Separator ..................................................................... Square Yard Geotextile, Separator, Non-Woven ................................................ Square Yard Geotextile, Stabilization ................................................................. Square Yard Geotextile, Stabilization, Non- Woven ............................................ Square Yard Road Grade Biaxial Geogrid .......................................................... Square Yard
D.General . The Engineer will measure Geotextile, Separator; Geotextile, Separator, Non -Woven; Geotextile, Stabilization; Geotextile, Stabilization, Non-Woven; and Road Gr ade Biaxial Geogrid in place to the limits shown on the plans. Geotextile, Separator; Geotextile, Separator, Non -Woven; Geotextile, Stabilization; and Geotextile, Stabilization, Non-Woven include furnishing the material, labor, and equipment required to furnish and place geotextiles and all materials and labor required to create seams. No allowance will be made for overlap, splices , or material cut off or wasted. Road Grade Biaxial Geogrid includes furnishing the material, labor, and equipment required to f urnish, place and anchor the geogrid, and any hand work necessary to establish grades and make geogrid splices. No allowance will be made for overlap, splices , or material cut off or wasted. The cost of aggregate or granular material, including additional quantities required to fill ruts, is included in the unit prices for related pay items.
Source: Michigan Standard Specifications for Construction, 2020 Edition. Pages 205–206 of 1,146.