Art. 251.01 Mulch SECTION 251. MULCH
251.01 Description. This work shall consist of furnishing, transporting, and
placing mulch, erosion control blanket, or turf reinforcement mat over seeded areas.
251.02 Materials. Materials shall be according to the following.
Item Article/Section
a.Compost ........................................................................................ 1081.05(b)
b.Mulch ............................................................................................. 1081.06(a)
c.Chemical Mulch Binder ............................................................. 1081.06(a)(3)
d.Chemical Compost Binder ........................................................ 1081.06(a)(4)
e.Excelsior Blanket ........................................................................... 1081.10(a)
f.Knitted Straw Mat .......................................................................... 1081.10(b)
g.Heavy Duty Erosion Control Blanket .............................................. 1081.10(c)
h.Wire Staples .................................................................................. 1081.10(d)
i.Wood Stakes ................................................................................. 1081.10(e)
j.Coconut Fiber ................................................................................. 1081.10(f)
k.Turf Reinforcement Mat ................................................................. 1081.10(g) CONSTRUCTION REQUIREMENTS
251.03 Mulch. Within 24 hours of seed placement, mulch by one of the
following methods shall be placed on the areas specified. On slopes steeper than 1:3 (V:H), mulch shall be applied the same day as seeded. Mulch shall be applied uniformly at the rate specified.
a.Method 1. This method shall consist of hand or machine application of straw mulch at the rate of 2 tons/acre (4.5 metric tons/ha). The mulch shall be loose enough to permit air to circulate but compact enough to reduce erosion. If baled mulch material is used, care shall be taken that the material is in a loosened condition and contains no lumps or knots of compacted material.
b.Method 2. This method shall consist of placing and stabilizing straw at the rate of 2 tons/acre (4.5 metric tons/ha) over seeded areas. All requirements of Method 1 must be met plus the mulch shall be thoroughly stabilized. The Contractor has the option of any of the following procedures for stabilizing the straw.
1.Procedure 1. This procedure shall consist of anchoring the straw into the soil by means of a mechanical stabilizer with dull blades or disks. These blades or disks shall be without camber, approximately 20 in. (500 mm) in diameter, notches spaced at approximately 8 in. (200 mm) intervals and equipped with scrapers. The stabilizer shall be approximately 1000 lb (450 kg), have a working width not exceeding 72 in. (1.8 m), and shall be equipped with a ballast compartment, so that when directed, the weight (mass) can be increased. Mulch Art. 251.03
2.Procedure 2. This procedure shall consist of stabilizing the straw with an approved mulch blower followed immediately by an overspray application of light-duty hydraulic mulch. The hydraulic mulch shall be according to Article 251.03(c) except that it shall be applied as a slurry of 900 lb (1020 kg) of mulch and 1000 gal (9500 L) of water per acre (hectare) using a hydraulic mulch applicator. The light-duty hydraulic mulch shall be agitated a minimum of five minutes before application and shall be agitated during application. The light-duty hydraulic mulch shall be applied from opposing directions to ensure even coverage.
3.Procedure 3. This procedure shall consist of stabilizing the straw with a chemical mulch binder. The chemical mulch binder may be applied simultaneously with the straw or as an overspray.
a.Simultaneous Application. The coated straw shall be placed by equipment which will blow or eject, by means of a constant air stream, controlled quantities of straw and binder in a uniform pattern. The binder shall be introduced into the air stream of the machine by means of a spray which will partially coat the straw with a spotty tack. If the straw is excessively cut or broken, corrective measures shall be taken.
b.Overspray Application. The overspray application shall be performed according to Procedure 2. The chemical mulch binder shall be approved by the Engineer and shall be applied at the rate recommended by the supplier and approved by the Engineer.
c.Method 3. This method shall consist of the machine application of a light- duty hydraulic mulch. Seeding shall be conducted as a separate operation and shall not be added to the hydraulic mulch slurry. Hydraulic mulch shall not be applied when the ambient temperature is at or below freezing. To achieve full and even coverage, the hydraulic mulch shall be applied from two opposing directions. Mixing and application rates shall be according to the manufacturer’s recommendations and meet the minimum application rates set in Article 1081.06(a)(2).
d.Method 3A. This method shall consist of the machine application of a heavy-duty hydraulic mulch. Seeding shall be conducted as a separate operation and shall not be added to the hydraulic mulch slurry. The hydraulic mulch shall not be applied when the ambient temperature is at or below freezing. To achieve full and even coverage, the hydraulic mulch shall be applied from two opposing directions. Mixing and application rates shall be according to the manufacturer’s recommendations and meet the minimum application rates set in Article 1081.06(a)(2). The heavy-duty hydraulic mulch shall be applied using a mechanically agitated hydraulic mulching machine.
e.Method 4. This method shall consist of applying compost combined with a performance additive designed to bind/stabilize the compost. The Art. 251.03 Mulch compost/performance additive mixture shall be applied to the surface of the slope using a pneumatic blower at a depth of 2 in. (50 mm). Following the mulching operation, foot and vehicular traffic, or the movement of equipment over the mulched area shall be prohibited. At any location where mulching has been displaced by any Contractor’s equipment or personnel, the seeding and mulch or other work damaged as a result of that displacement shall be repaired or replaced immediately.
251.04 Erosion Control Blanket. Erosion control blanket may be placed
using either excelsior blanket or knitted straw blanket. Within 24 hours of seed placement, blanket shall be placed on the areas specified. Prior to placing the blanket, the areas to be covered shall be relatively free of rocks or clods over 1 1/2 in. (40 mm) in diameter, and sticks or other foreign material which will prevent the close contact of the blanket with the seed bed. If, as a result of rain, the prepared seed bed becomes crusted or eroded, or if eroded places, ruts, or depressions exist for any reason, the Contractor shall rework the soil until it is smooth and reseed such areas which are reworked. After the area has been properly shaped, fertilized, and seeded, the blanket shall be laid out flat, evenly, and smoothly, without stretching the material. The excelsior and knitted straw blankets shall be placed so that the netting is on the top and the fibers are in contact with the soil. The heavy duty blankets shall be placed so that the heavy duty extruded plastic mesh is on the bottom. For placement in ditches, the erosion control blanket shall be applied parallel to the centerline of the ditch so that there are no longitudinal seams within 2 ft (600 mm) of the bottom centerline of the ditch. The blanket shall be toed in on the upslope edge and shingled or overlapped with the flow. On slopes, the blanket shall be applied either horizontally or vertically to the contour, toed in on the upslope edge, and shingled or overlapped with the flow. When placed adjacent to the roadway, blankets shall be toed in along the edge of shoulder. Anchoring the blankets shall be according to the manufacturer’s specifications.
251.05 Turf Reinforcement Mat (TRM). The TRM shall be specifically
manufactured for both temporary and permanent erosion control, revegetation, and the reduction of water velocities in ditches and overflows. TRM shall be placed the same day as seed placement. Prior to placing the TRM, the areas to be covered shall be relatively free of rocks or clods over 1 1/2 in. (40 mm) in diameter, and sticks or other foreign material which will prevent the close contact of the mat with the seed bed. If, as a result of rain, the prepared seed bed becomes crusted, or if eroded places, ruts, or depressions exist for any reason, the Contractor shall rework the soil until it is smooth and reseed such areas which are reworked. The TRM shall be installed according to the manufacturer’s recommendations. Sodding Art. 252.03
251.06 Method of Measurement. This work will be measured for payment as
follows.
a.Contract Quantities. The requirement for use of contract quantities shall be according to Article 202.07(a).
b.Measured Quantities. Mulch Methods 1, 2, 3, 3A, and 4 will be measured for payment in place in acres (hectares) of surface area mulched. Erosion control blanket, heavy duty erosion control blanket, and turf reinforcement mat will be measured for payment in square yards (square meters).
251.07 Basis of Payment. This work will be paid for at the contract unit price
per acre (hectare) for MULCH, METHOD 1; MULCH, METHOD 2; MULCH, METHOD 3; MULCH METHOD 3A; MULCH, METHOD 4; and at the contract unit price per square yard (square meter) for EROSION CONTROL BLANKET, HEAVY DUTY EROSION CONTROL BLANKET, or TURF REINFORCEMENT MAT. SECTION 252. SODDING
252.01 Description. This work shall consist of preparing the ground surface
and furnishing and placing sod and other materials required in the sodding operations.
252.02 Materials. Materials shall be according to the following.
Item Article/Section
a.Sod .................................................................................................... 1081.03
b.Salt Tolerant Sod ........................................................................... 1081.03(b)
c.Agricultural Ground Limestone .......................................................... 1081.07
d.Fertilizer ............................................................................................. 1081.08 CONSTRUCTION REQUIREMENTS
252.03 Ground Preparation. The area to be sodded shall be finished
according to Section 212 before sodding operations are begun. Immediately prior, but not in excess of 24 hours before the sod is placed, the soil surface shall be worked until it is free from debris, washes, gullies, clods and stones. The surface shall be worked to a depth of not less than 3 in. (75 mm) with a disk, tiller or other equipment approved by the Engineer. Prepared surface shall be finished to a fine smooth finish free of irregularities. Finished ground elevations shall allow for the thickness of sod to match grade of existing turf or structures. All soil surfaces shall be moist when the sod is placed. When directed by the Engineer, the Contractor shall be required to apply water to dry soil surfaces at a minimum rate of 1 gal/sq yd (5 L/sq m) immediately prior to placing the sod. When specified, agricultural ground limestone and fertilizer nutrients shall be applied at the designated rates over the areas to be sodded.
Referenced in this section
MULCH in other states
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Source: Illinois Standard Specifications for Road and Bridge Construction, 2022 Edition. Pages 129–132 of 1,217. View official source ↗