Section 4169. Erosion Control Materials
All materials required to be furnished and described in this section.
A. Furnish seeds approved for use according to requirements of this section, including specified purity and germination, as shown in Tables 4169.02-1 and 4169.02-2.
Table 4169.02-1: Seeds (Common Names, Scientific Names, Purity, and Germination)
|
Common Name |
Scientific Name |
Purity (%) |
Germination (%) |
|
DOMESTIC GRASSES |
|||
|
Bluegrass, Kentucky |
Poa pratensis |
85 |
80 |
|
Bluegrass, Ky. RAM-1 |
Poa pratensis-RAM-1 |
95 |
85 |
|
Bluegrass, Ky. PARK |
Poa pratensis-PARK |
95 |
85 |
|
Brome, smooth-LINCOLN |
Bromus inermis |
90 |
85 |
|
Fescue, tall, FAWN |
Festuca arundinacea-FAWN |
98 |
85 |
|
Fescue, chewings, red |
Festuca rubra var. commutate |
98 |
90 |
|
Fescue, creeping, red |
Festuca rubra |
98 |
85 |
|
Fescue, red-PENNLAWN |
Festuca rubra PENNLAWN |
98 |
85 |
|
Fescue, Tall, Olympic (Fineleaf) |
Festuca arundinacea-Olympic |
98 |
85 |
|
Fescue, Tall, Rebel (Fineleaf) |
Festuca arundinacea |
98 |
85 |
|
Fescue, Sheeps |
Festuca ovina |
98 |
85 |
|
Orchardgrass |
Dactylis glomerata |
90 |
90 |
|
Red top |
Agrostis alba |
92 |
85 |
|
Reed Canarygrass |
Phalaris arundinacea |
98 |
70 |
|
Wildrye, Canada |
Elymus Canadensis |
95 |
85 |
|
Wildrye, Russian |
Elymus junceus |
95 |
85 |
|
Ryegrass, Perennial |
Lolium perenne |
95 |
90 |
|
Timothy |
Phleum pratense |
99 |
85 |
|
LEGUMES |
|||
|
Alfalfa, RANGER/VERNAL |
Medicago sativa |
99 |
90(a) |
|
Alfalfa, Travois |
Medicoa spp. |
99 |
90(a) |
|
Birdsfoot Trefoil EMPIRE |
Lotus corniculatus |
98 |
85(a) |
|
Crownvetch, Emerald |
Coronilla varia |
98 |
70(a) |
|
Hairy Vetch |
Vicia villosa |
96 |
85(a) |
|
Lespedeza, Korean |
Lespedeza stipulacea |
98 |
80(a) |
|
Red Clover, medium |
Trifolium pretense |
99 |
90(a) |
|
Alsike Clover |
Trifolium hybridum |
99 |
90(a) |
|
White Clover |
Trifolium repens |
98 |
90(a) |
|
NURSE CROP OR STABILIZING CROP |
|||
|
Oats |
Avena sativa |
97 |
90 |
|
Rye |
Secale cereale |
97 |
90 |
| Sudangrass, PIPER |
Sorghum vulgare var. sudanese |
98 |
85 |
|
(a) Includes hard seed. |
|||
Table 4169.02-2: Seeds (Common Names, Scientific Names, and PLS)
|
Common Names |
Scientific Names |
PLS (%) |
|
*Furnish seed certified as Source Identified Class (Yellow Tag) Source G0-Iowa.
NATIVE GRASSES |
|
|
|
Big Bluestem* |
Andropogon gerardii |
30 |
|
Little Bluestem* |
Andropogon scoparius |
30 |
|
Switchgrass* |
Panicum virgatum |
63 |
|
Indiangrass* |
Sorghastrum nutans |
30 |
|
Sorghastrum nutans |
Bouteloua curtipendula |
30 |
|
Western Wheatgrass* |
Agropyron smithii |
56 |
|
Buffalograss* |
Buchloe dactyloides |
60 |
|
Sand Bluestem* |
Andropogon gerardii, var. paucipilus |
30 |
|
Blue Grama |
Bouteloua gracilis |
30 |
|
Intermediate Wheatgrass |
Agropyron intermedium |
70 |
|
Slender Wheatgrass |
Agropyron trachycaulum, var. unilaterale |
70 |
|
Prairie Dropseed |
Sporobolus heterolepis |
65 |
|
Sand Dropseed |
Sporobolus cryptandrus |
65 |
|
Sand Lovegrass |
Eragrostis trichodes |
65 |
|
Weeping Lovegrass |
Eragrostis curvula |
65 |
|
Hairy Wood Chess |
Bromus purgans |
60 |
|
Blue-joint grass |
Calamagrostis Canadensis |
47 |
|
Bottlebrush sedge |
Carex comosa |
62 |
|
Tussock sedge |
Carex stricta |
78 |
|
Fox sedge |
Carex vulpinoidea |
64 |
|
Virginia wild-rye |
Elymus virginicus |
60 |
|
Reed manna grass |
Glyceria grandis |
50 |
|
Fowl manna grass |
Glyceria striata |
72 |
|
Common rush |
Juncus effuses |
80 |
|
Rice Cut Grass |
Leesia oryzoides |
62 |
|
Rye grass, annual |
Lolium italicum |
89 |
|
Fowl bluegrass |
Poa palustris |
72 |
|
Green bulrush |
Scirpus atrovirens |
45 |
|
Wool grass |
Scirpus cyperinus |
78 |
|
Soft-stem bulrush |
Scirpus vallidus |
78 |
|
Indian grass |
Sorghastrum nutans |
60 |
|
Spike Rush |
Eleocharis palustris |
71 |
|
FORBS |
||
|
Canada anemone |
Anemone Canadensis |
72 |
|
Marsh milkweed |
Asclepias incarnate |
25 |
|
New England aster |
Aster novae-angliae |
25 |
|
Swamp aster |
Aster puniceus |
25 |
|
Showy tic-trefoil |
Desmodium canadense |
25 |
|
Joe-pye weed |
Eupatorium maculatum |
66 |
|
Boneset |
Eupatorium perfoliatum |
41 |
|
Ox Eye sunflower |
Heliopsis helianthoides |
38 |
|
Blue-flag iris |
Iris virginica-shrevii |
19 |
|
Meadow blazingstar |
Liatris ligulistylis |
24 |
|
Tall blazingstar |
Liatris pycnostachya |
24 |
|
Great blue lobelia |
Lobelia siphilitica |
13 |
|
Reed manna grass |
Glyceria grandis |
50 |
|
Fowl manna grass |
Glyceria striata |
72 |
|
Common Rush |
Juncus effuses |
80 |
|
Rice Cut Grass |
Leesia oryzoides |
62 |
B. Furnish all seeds, including grass, legume, forbs, and cereal crop seeds, from an established seed dealer or certified seed grower. Ensure they meet requirements of the Iowa Department of Agriculture regulations (Iowa Seed Law) and are labeled accordingly. Ensure the test date to determine the percentage of germination requirement was completed within a 9 month period exclusive of the calendar month in which the test was completed. Ensure the seed analysis on the label is mechanically printed.
C. Approval of all seed for use will be based on the accumulative total of PLS specified for each phase of the work, so that the PLS is not less than the accumulative total of the PLS specified. PLS is obtained by multiplying purity times germination.
D. If the seed does not comply with minimum requirements for purity and germination and such seed cannot be obtained, the Engineer may approve use of the seed on a basis of PLS or may authorize a suitable substitution for the seed specified.
E. The accumulative total of Pure Live Seed (PLS) is the product obtained by multiplying the pounds (kilograms) of each seed by the purity and germination percentages expressed as decimals. Calculations will be based on test results of samples taken by the Contracting Authority. If the seeds were not sampled or if these test results are not available, the PLS will be calculated from information shown on the label.
Furnish fertilizer of the grade, type, and form specified and that complies with Iowa Department of Agriculture rules and the following requirements:
A. Fertilizer grade will be identified according to the percent nitrogen (N), percent available phosphoric acid, (P2O5), and percent water soluble potassium, (K2O), in that order. Approval will be based on that identification.
B. Furnish all fertilizer from an established fertilizer dealer. Ensure guaranteed analysis is provided either through mechanically printed commercial fertilizer bags or through a manufacturer's (not a distributor's) bill of lading.
C. Fertilizer inspection and acceptance will be according to Materials I.M. 469.03.
D. Furnish fertilizer of a type that can be uniformly distributed by the application equipment. Fertilizer may be chemically combined or may be furnished as separate ingredients. If supplying chemically combined fertilizer, have each unit of fertilizer chemically combined. Ensure the manufacturer’s guarantee indicates compliance with this agreement. If supplying fertilizer as separate ingredients, comply with the following:
· Each of the separate ingredients of uniform size,
· Analysis guaranteed by the manufacturer.
· Mixed using a drum mixer, grinder mixer, or other mechanical mixers.
· Mixed only by the fertilizer dealer.
E. When 6-24-24 chemically combined commercial fertilizer has been specified, a combination of ammoniated phosphate (either monoammonium phosphate (11-52-0) or diammonium phosphate (18-46-0)), muriate of potash (granular form), and urea (granular form) may be used.
F. When 13-13-13 chemically combined commercial fertilizer has been specified, a combination of ammoniated phosphate (either monoammonium phosphate (11-52-0) or diammonium phosphate (18-46-0)), muriate of potash (granular form), and urea (granular form) may be used.
G. Fertilizer may be furnished in a dry or liquid form.
H. Furnish a list of the number of containers and a corresponding scale ticket from an approved scale for the fertilizer to be used in the work.
I. Official samples taken by the Contracting Authority may be tested. A tolerance of minus 1.0 percentage point from the guaranteed analysis for each nutrient will be considered substantial compliance.
J. Ground limestone is to be of the type known as No. 1 fine (70% passing No. 200 (75 µm) sieve) with an analysis of elemental calcium of no less than 37% or no more than 40%.
4169.04 INOCULANT FOR LEGUMES.
An inoculant is a culture of bacteria specifically formulated for legume seeds (alfalfa, clovers, lespedeza, birdsfoot trefoil, hairy vetch, and crownvetch). Ensure the manufacturer's container indicates the specific legume seed to be inoculated and the expiration date. Use inoculant that meets the requirements of the Iowa Seed Law. Follow the safety precautions specified on the product label.
A sticking agent is a commercial material recommended by the manufacturer to improve adhesion of inoculant to the seed. For quantities less than 50 pounds (25 kg), the sticking agent need not be a commercial agent; however, the Engineer’s approval is required. Apply separately prior to application of inoculant. Follow safety precautions specified on the product label. A sticking agent is not required if a liquid formulation of inoculant is used.
A. Use sod consisting of approximately 1 inch (25 mm) of well established turf consisting of live Kentucky bluegrass, unless otherwise specified. Ensure sod is free from roots of trees or brush, stones, and other objectionable materials. Ensure sod is free from all noxious weeds and reasonably free of all other weeds.
B. Ensure sod is cut in strips of uniform width and thickness with ends square. The Engineer may order the thickness adjusted to meet the sod conditions. Cut sod to the length specified for the use intended. If not specified, cut to a minimum length of 3 feet (1 m). Mow sod areas to a height of approximately 1 1/2 inches (40 mm) to 2 inches (50 mm) prior to cutting.
C. Ensure sod was regularly maintained prior to cutting. Apply pre-emergence weed control chemicals and weed control chemicals for broadleaf weeds.
D. Roll or stack sod within 1 hour after being cut. The Engineer may approve other methods of handling sod. Take precautions to prevent drying or heating. Do not use sod damaged by heat or dry conditions, or sod cut more than 18 hours before being incorporated into the work.
E. Sod will be subject to inspection by the Engineer at the job site, and approval of the work constitutes approval of the material.
Material used as mulch may consist of dry cereal straw or native grass straw. Use Certified Noxious Weed Seed Free Mulch certified by the Iowa Crop Improvement Association or other state’s Crop Improvement Associations. Bail cereal or native grass straw the same growing season as the grain was harvested from the plant.
1. Wood Cellulose Fiber.
a. Natural or cooked cellulose fiber processed from whole wood chips, or a combination of (50%-50%) cellulose fiber produced from whole wood chips and recycled fiber from sawdust, recycled paper, chipboard, or corrugated cardboard.
b. Contains a colloidal polysaccharide tackifier adhered to the fiber to prevent separation during shipment and avoid chemical coagglomeration during mixing.
c. Forms a homogeneous slurry of fibers, tackifier, and water that can be applied with standard hydraulic mulching equipment and be dyed green to facilitate visual metering during application.
d. Contains no growth or germination inhibiting factors, and has a minimum pH of 4.8.
2. Bonded Fiber Matrix.
a. Long-strand wood fibers held together by organic tackifiers and bonding agents that, when dry, become insoluble and non-dispersible.
b. Upon curing (24 to 48 hours) forms a continuous, 100% coverage, flexible, absorbent, erosion-resistant blanket that encourages seed germination.
c. Manufactured to be applied with standard hydraulic mulching equipment and dyed green to facilitate visual metering during application.
d. Contains no growth or germination inhibiting factors.
e. Physical Properties:
1) Fibers: Virgin wood, greater than 88% by volume.
2) Organic Material: Greater than 96% by volume.
3) Tackifier: 8 to 10%.
4) pH: 4.8 minimum.
5) Moisture Content: 12% ±3%.
6) Minimum Water Holding Capacity: 1.2 gallons per pound (10 L/kg).
f. All components pre-packaged by manufacturer to ensure material performance and compliance. Field mixing of additives or any components will not be allowed.
g. Other products not meeting requirements of Article 4169.07, B, 2, e, may be approved if they meet the following requirements:
1) Contain non-toxic tackifiers that upon drying become insoluble and non-dispersible to eliminate direct raindrop impact on soil according to ASTM D 7101 and EPA 2021.0-1.
2) Contain no germination or growth inhibiting factors and do not form a water-resistant crust that can inhibit plant growth.
3) Hydraulic mulch that is completely photo-degradable or biodegradable.
4) Contain a minimum 90% organic material according to ASTM D 2974.
5) Have a rainfall event (R-factor) of 140 < R according to ASTM D 6459.
6) Have a cover factor of C ≤ 0.03 according to ASTM D 6459.
7) Vegetation Establishment of 400% minimum according to ASTM D 7322.
8) Water Holding Capacity 600% minimum according to ASTM D 7367.
3. Mechanically-Bonded Fiber Matrix.
a. Long-strand wood fibers and crimped, interlocking synthetic fibers.
b. Upon curing (2 hours) forms a continuous, 100% coverage, flexible, absorbent, porous, erosion-resistant blanket that encourages seed germination.
c. Manufactured to be applied with standard hydraulic mulching equipment and dyed green to facilitate visual metering during application.
d. Contains no growth or germination inhibiting factors.
e. Physical Properties:
1) Virgin Wood Fibers: 73% minimum.
2) Crimped, Interlocking Synthetic Fibers: 5% ±1%.
3) Tackifier: 10% ±1%.
4) Moisture Content: 12% ±3%.
5) Minimum Water-Holding Capacity: 1.2 gallons per pound (10 L/kg).
6) pH: 4.8 minimum.
f. All components pre-packaged by manufacturer to ensure material performance and compliance. Field mixing of additives or any components will not be allowed.
g. Other products not meeting requirements in Article 4169.07, B, 3, e, may be approved if they meet the following requirements:
1) Contain non-toxic tackifiers that upon drying become insoluble and non-dispersible to eliminate direct raindrop impact on soil according to ASTM D 7101 and EPA 2021.0-1.
2) Contain no germination or growth inhibiting factors and do not form a water-resistant crust that can inhibit plant growth.
3) Hydraulic mulch that is completely photo-degradable or biodegradable.
4) Contain a minimum 90% organic material according to ASTM D 2974.
5) Have a rainfall event (R-factor) of 175 < R according to ASTM D 6459.
6) Have a cover factor of C ≤ 0.01 according to ASTM D 6459.
7) Vegetation Establishment of 500% minimum according to ASTM D 7322.
8) Water Holding Capacity of 700% minimum according to ASTM D 7367.
A. Use an organic substance produced by the biological and biochemical decomposition of source-separated compostable materials separated at the point of waste generation. Organic substances may include, but are not limited to:
· Leaf and yard trimmings,
· Food scraps,
· Food processing residues,
· Manure and/or other agricultural residuals,
· Forest residues and bark, and
· Soiled and/or unrecyclable paper and biosolids.
B. Compost is to contain no visible admixture of refuse or other physical contaminants nor any material toxic to plant growth. Compost is to meet the additional requirements below. All physical requirements are to comply with the United States Composting Council, “Testing Methods for the Examination of Composting and Compost” (TMECC).
1. Minimum organic material: 30% (dry weight (mass) basis) as determined by loss on ignition.
2. Moisture content: 30% to 60%. Organic material shall be loose and friable and not dusty.
3. Soluble salts: less than 5.0 ds/m.
4. Stability: Carbon dioxide evolution rate less than 8 according to TMECC 5.08-B. Growth screening: Emergence a minimum of 80% for all compost to be vegetated.
5. pH: 6.0 - 8.0.
6. Fecal Coliform: Comply with TMECC 07.01-B.
7. Heavy Metals: Comply with TMECC 04.06 and TMECC 04.13-B.
8. Comply with the following for particle size:
· Pneumatic Seeding (Urban): 100% passing the 1/2 inch (12.5 mm) screen.
· Pneumatic or Mechanical Seeding (Rural): 100% passing the 1 inch (25 mm) screen, 80% to 90% passing the 3/4 inch (19 mm) screen, and 70% to 80% passing the 1/2 inch (12.5 mm) screen.
· Filter Sock, Filter Berm, and Filter Blanket: 100% passing the 2 inch (50 mm) screen, 70% to 90% passing the 1 inch (25 mm) screen, and 50% to 70% passing the 1/2 inch (12.5 mm) screen.
4169.09 STAKES FOR HOLDING SOD.
Use either wood or metal wire stakes for holding sod. Use wood stakes in sandy soils or when the Engineer requires.
· 1 inch (25 mm) to 1 1/2 inches (40 mm) wide, 1/4 inch (6 mm) to 1/2 inch (13 mm) thick, and 12 inches (300 mm) long.
· Where this length of stake does not provide firm bearing, the Engineer may require stakes of sufficient length to secure firm bearing.
· Staples made from No. 11 (3.06 mm diameter) wire or heavier and with a minimum 2 inch (50 mm) flat spread on the top of the sod.
· Legs at least 6 inches (150 mm) long. The Engineer may require wire legs longer than 6 inches (150 mm).
4169.10 SPECIAL DITCH CONTROL, turf reinforcement mat, SLOPE PROTECTION, and Outlet or channel scour protection (transition mat).
Comply with the following and meet the requirements of Materials I.M. 469.10.
Meet the following requirements for wire staples for holding special ditch control wood excelsior mat and special ditch control jute mesh over sod:
1. U-shaped wire staples.
2. Each leg a minimum of 6 inches (150 mm) long. In sandy soil conditions the Engineer may require the length of each leg to be a minimum of 12 inches (300 mm).
3. No. 11 (3.06 mm) diameter wire.
4. Staples of sufficient hardness to facilitate installation without bending.
1. Wood Excelsior Mat.
A mat of interlocking wood fibers. Meet the following requirements:
· Plastic netting applied to both sides for holding the excelsior in place.
· Nontoxic to growth of plants and germination of seeds.
· Minimum dry weight (mass) of 0.68 pounds per square yard (334 g/m2) according to ASTM D 6475.
· Furnished in rolls with a uniform width of 48 inches (1.2 m), with a tolerance of minus 1 inch (25 mm) and a minimum length of 80 feet (24 m).
· Furnished in plastic bags or otherwise protected to prevent damage from weather and handling.
2. Coconut Fiber Mat.
At the Contractor's option, coconut fiber mat may be substituted for wood excelsior mat for special ditch control. Meet the following requirements:
· Uniform thickness with the coconut fiber evenly distributed over the entire area of the mat.
· Both sides of the mat covered with polypropylene netting attached with cotton thread.
· Minimum dry weight (mass) of 0.40 pounds per square yard (182 g/m2) according to ASTM D 6475.
· Furnished in rolls with a uniform width of 48 inches (1.2 m) with a tolerance of minus 1 inch (25 mm) and a minimum length of 80 feet (24 m).
· Furnished in plastic bags or otherwise protected to prevent damage from weather and handling.
Wood excelsior mat, coconut fiber mat, straw mat, or straw coconut mat may be used for slope protection.
1. Wood Excelsior Mats.
A mat of interlocking wood fibers meeting the requirements of Article 4169.10, B, 1. with the following exceptions:
· Plastic netting applied to one or both sides for holding the excelsior in place. Mats without netting where the excelsior is mechanically stitched together to hold it in place may be allowed.
· Minimum dry weight (mass) of 0.50 pounds per square yard (246 g/m2) according to ASTM D 6475.
2. Straw Mat, Straw-Coconut Fiber Mat, or Coconut Fiber Mat.
At the Contractor's option straw mat, straw-coconut fiber mat, or coconut fiber mat may be substituted for wood excelsior mat for slope protection. Meet the following requirements:
· Consistent thickness with the straw, straw-coconut fiber, or coconut fiber evenly distributed over the entire area of the mat.
· The top side of the mat covered with polypropylene netting attached with cotton thread.
· Minimum dry weight (mass) of 0.40 pounds per square yard (182 g/m2) according to ASTM D 6475.
· Furnished in rolls with a uniform width of 48 inches (1.2 m), with a tolerance of minus 1 inch (25 mm) and a minimum length of 80 feet (24 m).
· Furnished in plastic bags or otherwise protected to prevent damage from weather or handling.
1. Comply with the following mesh netting sizes. A tolerance of plus or minus 0.10 inch (2.5 mm) applies to netting size.
· Netting applied on wood excelsior mats: no more than 1 inch by 2 inches (25 mm by 50 mm).
· Netting applied on coconut fiber only mats for channel and slope: no more than 3/4 inch by 3/4 inch (19 mm by 19 mm).
· Netting applied on the top side of straw and straw-coconut fiber mats for slopes only: no more than 1/2 inch by 1/2 inch (13 mm by 13 mm).
2. A minimum weight of 9 pounds per 1000 square yards (44 g/m2) is required for netting for special ditch control or slope protection.
E. Turf Reinforcement Mat (TRM).
1. Type 1 TRM: constructed of a web of mechanically or melt-bonded polymernetting, or monofilaments fibers entangled to form a strong and dimensionally stable mat. Bonding methods include polymer welding, thermal or polymer fusion, or the placement of synthetic fibers between two high-strength, biaxially-oriented nets, mechanically bound by parallel stitching with polyolefin thread. Products may contain a degradable component.
2. Type 2 and 3 TRM: constructed of a web of mechanically or melt-bonded polymer netting, or monofilaments, or fibers that are entangled to form a strong and dimensionally stable mat. Non-woven bonding methods include polymer welding, thermal or polymer fusion, or the placement of fibers between two high-strength, biaxially oriented nets, mechanically bound by parallel stitching with polyolefin thread. Components are to be 100% synthetic and resistant to biological, chemical, and ultraviolet degradation.
3. Type 4 TRM: a high performance/survivability TRM composed of monofilament yarns woven into a resilient uniform configuration. Use mats consisting of a matrix exhibiting very high interlock and reinforcement capacities with both soil and root systems and demonstrating a high tensile modulus. TRMs manufactured from discontinuous or loosely held together by stitched or glued, netting, or composites will not be allowed in this category. Components are to be 100% synthetic and resistant to biological, chemical, and ultraviolet degradation. Use this category when field conditions exist with high loading and/or high survivability requirements.
4. Comply with Table 4169.10-1 for minimum material property and performance requirements:
|
Table 4169.10-1: Minimum Material Property and Performance Requirements |
||||||
|
Property |
Property |
Test Method |
Type 1 |
Type 2 |
Type 3 |
Type 4 |
|
Material |
Thickness |
ASTM D 6525 |
0.25 in (6.25 mm) |
0.25 in (6.25 mm) |
0.25 in (6.25 mm) |
0.25 in (6.25 mm) |
|
Material |
Tensile Strength(a, b) |
ASTM D 6818 |
125 lb/ft (186 kg/m) |
240 lb/ft (357 kg/m) |
750 lb/ft (1116 kg/m) |
3000 lb/ft (4465 kg/m) |
|
Material |
UV Resistance |
ASTM D 4355 |
80% @ 500 hrs |
80% @ 1000 hrs |
80% @ 1000 hrs |
90% @ 3000 hrs |
|
Performance |
Maximum Shear Stress (Channel Applications)c |
ASTM D 6460 |
7-9 lb/ft2 (34.2 - 43.9 kg/m2) |
10-11 lb/ft2 (48.8 - 53.7 kg/m2) |
12-14 lb/ft2 (58.6 - 68.4 kg/m2) |
15-16 lb/ft2 (73.2 - 78.1 kg/m2) |
|
Performance |
Maximum Slope Gradient (Slope Applications) |
N/A |
1:1 (H:V) or flatter |
1:1 (H:V) or flatter |
1:1 (H:V) or greater |
1:1 (H:V) or greater |
|
a. Minimum Average Roll Values, machine direction only. b. Tensile Strength of structural components retained after exposure. c. Maximum shear stress that fully-vegetated TRM can sustain without physical damage or excess erosion (1/2 inch (12.5 mm) soil loss) during a 30 minute flow event in large scale testing. Acceptable large scale testing protocol includes ASTM D 6460 or independent testing conducted by the Texas Transportation Institute, Colorado State University, Utah State University, or other approved testing facility. Bench scale testing is not acceptable. |
||||||
F. Outlet or Channel Scour Protection (Transition Mat)
1. Mat.
a. Constructed of 85% minimum UV resistant material with a maximum ground cover of 80%.
b. Meet the requirements of Table 4169.10-2:
Table 4196.10-2: Material Property and Performance Requirements
|
Property |
Test Method |
Value |
|
Mass/Unit Area (max) |
ASTM D 6566 |
3 lbs/ft2 (15 kg/m2) |
|
Thickness (min) |
ASTM D 6525 |
0.4 in (10 mm) |
|
Thickness (max) |
ASTM D 6525 |
1.1 in (28 mm) |
|
Tensile Strength (TD) |
ASTM D 6818 |
550 lbs/ft (820 kg/m) |
|
Percent Open Area (min) |
ASTM D 6567 |
20% |
|
UV Stability |
ASTM D 4355 |
85% |
2. Anchoring Devices.
a. Furnish bullet tip style anchors made of a metal alloy attached to a wire rope.
b. Anchors capable of withstanding a minimum 300 pounds (136 kg) of pull out resistance in cohesive soils.
c. Wire rope a minimum of 30 inches (762 mm) in length with a minimum breaking strength of at least 300 pounds (136 kg).
d. The top washer a minimum of 3 inches (76 mm) in diameter and constructed of a UV resistant plastic.
e. Each anchor equipped to allow the retightening of the anchor when deemed necessary by the Engineer.
4169.11 Filter Fabric.
Furnish nonwoven polypropylene, UV stabilized filter fabric complying with Table 4169.11-1.
|
Table 4169.11-1: Filter Fabric Properties |
||
|
Property |
Typical |
Minimum |
|
Tensile Strength, lbs (metric) |
130 (metric) |
115 (metric) |
|
Grab Elongation, % |
70 |
50 |
|
Trapezoidal Tear Strength, lbs (metric) |
60 (metric) |
50 (metric) |
4169.12 Perimeter and Slope Sediment Control Device.
1. Provide wattles, sediment logs, and filter socks consisting of wood products (including wood mulch), cereal grain straw, or native grass straw contained in a tube of photo degradable fabric or synthetic netting.
2. Fill wattles, sediment logs, and filter socks using a mechanical device. Hand filling of wattles, sediment logs, and filter socks will not be allowed.
3. Ensure wattles, sediment logs, and filter socks do not contain:
• A visible admixture of refuse or other physical contaminants,
• Germination or growth inhibiting factors, or
• Material toxic to plant growth.
4. Ensure wattles, sediment logs, and filter socks have waterproof identification tags printed using permanent ink and containing manufacturer’s name and address. For wattles and sediment logs, tags shall be attached to the inside of the netting of each wattle or sediment log. For filter socks, tags shall be attached to the outside of each sock.
5. Approved perimeter and slope sediment control devices are listed in Materials I.M. 469.10, Appendix E.
1. Ensure cereal grain straw for wattles or sediment logs is Certified Noxious Weed Seed Free Mulch certified by the Iowa Crop Improvement Association or other state’s Crop Improvement Associations.
2. Wattles or sediment logs with observed unharvested seed heads will not be accepted.
3. For wood excelsior sediment logs and straw wattles, meet the following minimum weight (mass) requirements:
• 20 inch (510 mm) sediment logs and straw wattles: 3 pounds per foot (4.45 kg/m) with tolerance of 0.25 pounds per foot (0.40 kg/m).
• 12 inch (300 mm) sediment logs and straw wattles: 2 pounds per foot (3.00 kg/m) with tolerance of 0.25 pounds per foot (0.40 kg/m).
• 9 inch (230 mm) sediment logs and straw wattles: 1 pound per foot (1.50 kg/m) with a tolerance of 0.1 pounds per foot (0.15 kg/m).
• 6 inch (150 mm) sediment logs and straw wattles: 0.5 pounds per foot (0.75 kg/m) with a tolerance of 0.1 pounds per foot (0.15 kg/m).
Provide filter socks with a maximum 3/8 inch (10 mm) opening and filled with a compost/wood blend filter material consisting of compost from an approved source meeting Article 4169.08.