168 SECTION 253
253.01 Description
This work consists of grass hay or straw mulching, and hydraulic mulching.
253.02 Equipment
A.Hydraulic Mulch. When applying hydraulic mulch and seed together use hydraulic spraying equipment that mixes the seed and mulch in water.
B.Straw Mulch. Use equipment that uniformly distributes the mulch over the seedbed. Use a puncher that consists of a series of dull, flat disks: − With notched or cutout edges; − Approximately 20 inches in diameter; − 0.25 inches thi ck; − Spaced approximately 8 inches apart; and − Fitted with scrapers.
253.03 Materials
A.Seed. Use the seed classification shown in the bid item that meets the requirements of Section
251.03 D, “Seed Class” .
B.Hydraulic Mulch. Use hydraulic mulch free of germination or growth inhibiting factors. Provide hydraulic mulch free of recycled paper and toxins. Provide hydraulic mulch with fibers that are capable of absorbing water and allowing infiltration to the underlying soil without restricting emergence of seedlings.
C.Straw Mulch. Use mulch material consisting of straw from cereal grain or native hay. The mulch shall be free of seed bearing stalks of noxious weeds as defined by the North Da kota Department of Agriculture. The Engineer will not accept mulch that: − Is wet, musty, moldy, or rotted; − Is chopped or ground; or − Contains deleterious material.
D.Tackifier. Use a tackifier consisting of one of the following:
1.Water soluble natural proteins, vegetable gums, or guar gums blended with gelling and hardening agents. Guar gum based tackifier shall consist of a minimum of 95 169 percent guar gum by weight with the remainder consisting of dispersing and cross -link additives.
2.Water soluble blend of hydrophilic polymers, viscosifiers, sticking aids and other gums.
E.Bonded Fiber Matrix. Use a bonded fiber matrix consisting of a continuous layer of elongated fiber strands held together by a water resistant bonding agent. The matrix shall be 100 percent biodegradable and composed of, by weight, 90 percent wood fiber, 9 percent natural binder and 1 percent organic and mineral activators.
253.04 Construction Requirements
A.General. Uniformly cover seeded areas with mulch within 24 hours of initiating seeding. Protect traffic, signs, structures, and other objects from being marked or splattered by the material.
B.Hydraulic Mulch.
1.General. Use mulch that is evenly dispersed and suspended in agitated water. Apply at a rate of one ton per acre with a minimum of 95 percent coverage of the seedbed. When hydraulic mulch is required, the specified seed mixture may be combined with the hydraulic mulch and applied in a single application.
2.Temporary Care Maintenance. Keep the soil in the mulch area moist a minimum of 3 inches deep for the first 21 days. The Engineer will not require watering between October 1 and May 15 in areas with hydraulic seeding.
3.Seasonal Limitations. If applying seed mixture and hydraulic mulch in a single application, the timeframes specified in Section 251.04 C, “Seasonal Limitations” will apply.
C.Straw Mulch.
1.Application. Place mulch at a rate of 2 tons per acre. Do not perform mulching operations when the sustained wind velocity is greater than 25 miles per hour. Avoid placing excessive cover that smothers seedlings.
2.Anchoring. Anchor mulch using one of the following methods to: 170 a. Punching. Immediately following ap plication, punch mulch into the soil using a puncher. Operate the tiller parallel to the contours of the ground. Push the mulch into the soil 3 inches, with the ends of the mulch exposed above the soil surface.
b.Tackifier. Use tackifier on areas where slopes are steeper than 3:1 Apply the tackifier at the rate recommended by the manufacturer. If no manufacturer recommendations are available, apply at a rate between 175 and 275 pound per acre by spraying with the mulch or imm ediately following the mulching application.
3.Maintenance. Repair or re-mulch damaged areas.
D.Bonded Fiber Matrix. Apply at the manufactures recommended rate or 3,900 pounds per acre and use a mix consisting of 1 pound bonded fiber matrix to 12.5 gal lons water. Install the matrix with hydraulic seeding equipment.
253.05 Method of Measurement
The Engineer will measure, completed and in place, as specified in Section 109.01, “Measurement of Quantities”.
253.06 Basis of Payment
Pay Item Pay Unit Straw Mulch Acre, Square Yard Hydraulic Mulch Acre, Square Yard Bonded Fiber Matrix Acre, Square Yard Such payment is full compensation for furnishing all materials, equipment, labor, and incidentals to complete the work as specified. Section 255 171 SECTION 255 EROSION CONTROL BLANKET AND TURF REINFORCEMENT MAT
255.01 Description
This work consists of placing an Erosion Control Blanket (ECB) or Turf Reinforcement Mat (TRM) on a prepared slope or channel.
255.02 Equipment
Reserved.
255.03 Materials
Item Section Erosion Control Blanket and Turf Reinforcement Mat 856
255.04 Construction Requirements
A.General. Remove all rocks or clods greater than 1 inch in diameter, and all sticks and deleterious material from the area to be covered.
B.ECB and TRM Type 1. Complete seeding before placing ECB and TRM.
C.TRM Type 2. If the TRM requires soil filling, fill the TRM with topsoil, compost, or a blend of topsoil and compost. Place seed and fertilizer on the soil filled TRM. Apply hydraulic mulch or place ECB on the seeded TRM. Place the ECB with the netting on top and the fibers in contact with the soil. In ditches, unrol l the ECB and TRM starting from the top of the slope and perpendicular to contours. On embankments shorter than 10 feet, unroll the ECB horizontally or vertically to the slope.
D.Repair of ECB and TRM. Restore the damaged area to the proper contour. S eed as specified in Section 251 “Seeding” . Replace the ECB and TRM with the required type.
255.05 Method of Measurement
The Engineer will measure, completed and in place, as specified in Section 109.01 “Measurement of Quantities”. The Engineer will not measure overlaps or buried portions of the ECB or TRM.
Source: North Dakota Standard Specifications for Road and Bridge Construction, 2022 Edition. Pages 203–205 of 550.