Large-Scale Channel Erosion Testing (ASTM D …

1 Large-Scale Channel Erosion Testing ( astm D 6460) of ErosionTech s ET-X2HV, Double Net Excelsior Blanket over Loam July 2012 Submitted to: AASHTO/NTPEP 444 North Capitol Street, NW, Suite 249 Washington, 20001 Attn: Evan Rothblatt, NTPEP Submitted by: TRI/Environmental, Inc. 9063 Bee Caves Road Austin, TX 78733 C. Joel Sprague Project Manager July 31, 2012 Mr. Evan Rothblatt AASHTO/NTPEP 444 North Capitol Street, NW, Suite 249 Washington, 20001 E-mail: Subject: Channel Testing over Loam of ET-X2HV, Double Net Excelsior Blanket, manufactured by ErosionTech in Juliette, GA Dear Mr.

2 Rothblatt: This letter report presents the results for Large-Scale Channel Erosion tests performed on ET-X2HV, Double Net Excelsior Blanket, over Loam. Included are data developed for target hydraulic shears ranging from to 3+ psf ( to + kPa). All Testing work was performed in general accordance with the astm D 6460, Standard Test Method for Determination of Rolled Erosion Control Product (RECP) Performance in Protecting Earthen Channels from Stormwater-Induced Erosion . Generated results were used to develop the following permissible or limiting shear ( limit) and limiting velocity (Vlimit) for the tested material: limit ET-X2HV, Double Net Excelsior Blanket & staples/sy = psf; Vlimit ET-X2HV, Double Net Excelsior Blanket & staples/sy = ft/sec TRI is pleased to present this final report.

3 Please feel free to call if we can answer any questions or provide any additional information. Sincerely, C. Joel Sprague, Senior Engineer Geosynthetics Services Division Cc: Sam Allen, Jarrett Nelson - TRI ET-X2HV, Double Net Excelsior Blanket, over Loam Channel Erosion Testing July 31, 2012 Page 3 Channel Testing REPORT ET-X2HV, Double Net Excelsior Blanket, over Loam Testing EQUIPMENT AND PROCEDURES Overview of Test and Apparatus TRI/Environmental, Inc.'s (TRI's) Large-Scale Channel Erosion Testing facility is located at the Denver Downs Research Farm in Anderson, SC.

4 Testing oversight is provided by C. Joel Sprague, The Large-Scale Testing is performed in a rectangular flume having a 10% slope using a loamy soil test section. The concentrated flow is produced by raising gates to allow gravity flow from an adjacent pond. At least four sequential, increasing flows are applied to each test section for 30 minutes each to achieve a range of hydraulic shear stresses in order to define the permissible, or limiting, shear stress, limit, which is the shear stress necessary to cause an average of inch of soil loss over the entire Channel bottom.

5 Testing is performed in accordance with astm D 6460 protocol. Tables and graphs of shear versus soil loss are generated from the accumulated data. Rolled Erosion Control Product (RECP) The following information and index properties were determined from the supplied product. Table 1. Tested Product Information & Index Properties Product Information and Index Property / Test Units Sampled Product Product Identification - ET-X2HV Manufacturer - ErosionTech Manufacturing Plant Location - Juliette, GA Lot number of sample - - Fiber - 100% Aspen Excelsior Netting Openings in x (top) Stitching Spacing in (approx) Tensile Strength MD x XD ( astm D 6818)* lb/in x Tensile Elongation MD x XD ( astm D 6818)* % x Thickness ( astm D 6525)* mils 438 Light Penetration ( astm D 6567)

6 * % cover Water Absorption ( astm D 1117 & ECTC-TASC 00197)* % Wt Change 186 Mass / Unit Area ( astm D 6475)* oz/sy * Values from Independent Testing of Randomly Sampled Product ET-X2HV, Double Net Excelsior Blanket, over Loam Channel Erosion Testing July 31, 2012 Page 4 Test Soil The test soil used in the test plots had the following characteristics. Table 2. TRI-Loam Characteristics Soil Characteristic Test Method Value % Gravel astm D 422 0 % Sand 45 % Silt 35 % Clay 20 Liquid Limit, % astm D 4318 41 Plasticity Index, % 8 Soil Classification USDA Loam Soil Classification USCS Sandy silty clay (ML-CL) Preparation of the Test Channels The initial Channel soil veneer (12-inch thick minimum) is placed and compacted.

7 Compaction is verified to be 90% ( 3%) of Proctor Standard density using astm D 698 (sand cone method). The test channels undergo a standard preparation procedure prior to each test. First, any rills or depressions resulting from previous Testing are filled in with test soil. The soil surface is replaced to a depth of 1 inch and groomed to create a Channel bottom that is level side-to-side and at a smooth 10% slope top-to-bottom. Finally, a vibrating plate compactor is run over the renewed Channel surface.

8 The submitted Erosion control product is then installed using the anchors and anchorage pattern directed by the client. Installation of Erosion Control Product in Test Channel As noted, the submitted Erosion control product is installed as directed by the client. For the tests reported herein, the Erosion control product was anchored using a diamond anchorage pattern consisting of 2 x 8 steel staples to create an anchorage density of approximately anchors per square yard.

9 Specific Test Procedure Immediately prior to Testing , the initial soil surface elevation readings are made at predetermined cross-sections. The Channel is then exposed to sequential 30-minute flows having typical target hydraulic shear stresses ranging from to 3+ psf. During the Testing , flow depth and corresponding flow velocity measurements are taken at the predetermined cross-section locations. Between flow events, the flow is stopped and soil surface elevation measurements are made to facilitate calculation of soil loss.

10 Flows are then increased to achieve the subsequent shear target in an attempt to create more than inches of soil loss. Pictures of Channel flows and resulting soil loss are shown in Figures 6 thru 12. ET-X2HV, Double Net Excelsior Blanket, over Loam Channel Erosion Testing July 31, 2012 Page 5 Figure 1. Flumes Setup (typical) Figure 2. Flow Velocity Measurement in Channel (typical) Figure 3. Channel Flow Depth Measurement (typical) Figure 4. RECP Installed (typical) Figure 5. Typical Low Flow in Channels Figure 6.