347 SECTION 744
744.01 Description
This work consists of furnishing and installing extruded expanded polystyrene insulation board.
744.02 Equipment
Equipment Section Self-Propelled Pneumatic -Tired Rollers 151.01 C
744.03 Materials
Use polystyrene insulation board that meets the requirements of AASHTO M 230.
744.04 Construction Requirements
A.Base Preparation. Compact and level the base material. Place the board on base that is smooth and level and without point loadings. Do not operate construction equipment on the insulation board. The Engineer will allow placing a layer of sand as a base.
B.Installation. Stagger the insulation boards so the transverse joints are not continuous and are at least 4 feet apart. If multiple layers of insulation are used, place vertical joints in a successive layer a minimum of 6 inches from the joint in the preceding layer. Place boards so that the gap between two boards is less than 1/4 inch. Take any necessary steps to prevent the boards from moving during backfill placement.
C.Cover Material. Place a first lift of 12 inches of loose material on the insulation board. Compact the cover material with pneumatic -tired rollers or hand operated mechanical tamper. Do not drive equipment, other than the compaction equipment, over the insulation board until the first lift of material has been placed and compacted.
744.05 Method of Measurement
The Engineer will measure completed and in place as specified in Section 109.01, “Measurement of Quantities.”
744.06 Basis of Payment
Pay Item Pay Unit Insulation Board Cubic Foot 348 Such payment is full compensation for furnishing all materials, equipment, labor, and incidentals to complete the work as specified. Section 748 349 SECTION 748 CURB AND GUTTER
748.01 Description
This work consists of constructing curb, gutter, or combination curb and gutter.
748.02 Equipment
Equipment Section Concrete Equipment 155
748.03 Materials
Item Section Concrete Class AE 802 Impervious Membrane Cure 810.01 B .1 or 810.02 B.2 Joint Materials 826 Expansion Joint Material 826.02 C or F Reinforcing Steel, Dowel Bars, and Tie Bars 836
748.04 Construction Requirements
A.General. Construct curb and gutter using a slip-form machine or full depth fixed forms. Do not allow traffic or equipment on newly placed concrete until it has attained a flexural strength of 450 psi or a compressive strength of 3,000 psi .
B.Excavation. Eliminate deviations greater than 1/2 inch when measured with a 10 foot straightedge. Compact the subgrade as specified in Section 203.04 G .4, “Compaction Control, Type C” . Remove all soft and yielding materials and replace the volume with aggregate base.
C.Mixing, Placing, and Finishing. Place curb and gutter concrete on a damp base. Consolidate the concrete by vibration. Check the top and face of curbs with a 10 foot straightedge and correct all variations gr eater than 1/4 inch in 10 feet before the final finish. Finish the exposed surfaces with a moistened wood float and a stiff bristled broom. Do not place concrete on or against frozen ground. If honeycombed areas are exposed when the forms are removed, the Engineer will determine if replacement is required. If replacement is not required, repair the honeycombed areas. When repairing the honeycombed areas, use mortar composed of one part cement and two parts sand, mixed with water. Do not use water to facilitate finishing.
Source: North Dakota Standard Specifications for Road and Bridge Construction, 2022 Edition. Pages 382–383 of 550.