Specifications include, but are not limited to: Materials to be used for geogrid reinforced base construction shall consist of virgin crushed stone, recycled Portland cement concrete, or a blend of recycled Portland cement concrete and Reclaimed Asphalt Pavement (RAP). This blend is not to exceed 50% RAP and shall be tested by use of an asphalt burn off oven to ensure compliance. All materials shall meet the following gradation specification. Asphalt cement shall be of uniform consistency, free from water to the extent that it will not foam when heated to three hundred fifty degrees (350°) F., and it shall meet the following requirements for physical and chemical properties: Polymer Modified Performance Grade Asphalt Cement Original Binder: Flash Point (°C), 230 Rotational Viscosity at 135 °C (Pa’s), 3 max Dynamic Shear at grade temperature (kPa), 1.00 min Separation (°C max), 2 max Trench stabilization must be installed when any level of groundwater or unstable soils are encountered. Trench stabilization for sanitary/storm sewer pipe will consist of over excavation and placement of Type I bedding material, a minimum of six inches under and on the sides of the pipe, up to middle of the pipe. Any trench stabilization required as a result of surface water entering the trench or to correct inadvertent over-depth trenching will be installed at the Contractor’s expense. All Type I bedding material for trench stabilization must be approved by the City’s Materials Testing Lab prior to use.