Quality Control, Quality Assurance and Performance Testing of ECPs. Erosion. Erosion Control

Transcription

1 Testing and Specifying Rolled Erosion Control Products (RECPs) Presented by: C. J. (Joel) Sprague, TRI/Environmental, Inc., United States J. E. (Jay) Sprague, TRI s Denver Downs Research Facility, United States What are Rolled Erosion Control Products (RECPs)? Temporary RECPs - For applications where natural vegetation alone will provide sufficient permanent erosion protection. Open Weave Textile (OWT). Erosion Control Blanket (ECB). Permanent RECPs - For applications where natural vegetation alone will not sustain expected flow conditions and/or provide sufficient long-term erosion protection. Turf reinforcement mat (TRM) Erosion Quality Control, Quality Assurance and Performance Testing of ECPs Basic index tests to assure Manufacturing Quality Control (MQC) and to bench-marking materials tested for performance. Quality Assurance (MQA). Basic index tests (verify MQC), and Bench-scale performance tests. Performance tests to answer designers and specifiers questions regarding relative performance of different products or installation techniques. Erosion Control What ASTM Index Test Methods Are Used for RECPs (and HECPs) D Mass per Unit Area of Turf Reinforcement Mats D Mass Per Unit Area of Erosion Control Blankets D Nominal Thickness of Permanent Rolled Erosion Control Products D Ultimate Tensile Properties of Rolled Erosion Control Products D Light Penetration of Rolled Erosion Control Products 1

2 What ASTM Index Test Methods Are Used for RECPs (and HECPs) ASTM D 1117 Section 5.4 and ECTC-TASC Standard Test Method for Determining Water Absorption of RECPs ASTM D 792, Method A, Standard Test Methods for Density and Specific Gravity... D6566 requires the specimen area to be not less than 23,000 mm 2 (35.6 in 2 ). 10 x 10 specimens are commonly used. What other Index Test Methods are Available for RECPs? D Short-term Compression Behavior of Turf Reinforcement Mats (TRMs) D Resiliency of Turf Reinforcement Mats (TRMs) D Stiffness of Geosynthetics Used as Turf Reinforcement Mats (TRMs) Weigh at least 5 test specimens Mass/Unit Area (ASTM D 6566) TRMs Mass/Unit Area (ASTM D 6475) RECPs of Natural Materials (and HECPs) 2

3 Thickness (ASTM D 6525) All RECPs (and HECPs) Weigh at least 5 test specimens Place specimens in forced air oven at 50C for at least 8 hours (typically overnight) 10 x 10 specimens are commonly used. Weigh oven dried specimens Lower presser foot (6-inch diameter) onto specimen applying 0.2 kpa (0.029 psi) and record reading 5 seconds after load is applied- repeat for 10 specimens 3

4 Tensile (ASTM D 6818) All RECPs (and HECPs) 4 x 6 specimens are used for most materials. Standard constant rate of extension materials testing machine Clamps with parallel jaw faces 1 inch tall and at least 1 inch wider than sample 5 MD and 5 TD specimens are cut. 4

5 Specimen is tensioned at 12 in/min. Test is terminated after specimen ruptures Determination of the amount of light transmitted through an RECP as a percentage Results are reported as a percentage of light transmission Adjust light source to achieve maximum reading without sample Light Penetration (ASTM D 6567) All RECPs (and HECPs) Record light reading with no specimen, and then place specimen in light box x 10 specimens are commonly used.... And record light reading with specimen 5

6 Water Absorption (ECTC Method) All RECPs (and HECPs) After 24 hours, remove specimens and allow to drain for 10 minutes. Then weigh wet specimens Specific Gravity (ASTM D 792) TRMs Only 10 x 10 specimens are commonly used. Weigh at least 5 test specimens, place specimens in stacked trays allowing room for expansion, and place stacked trays in container filled with DI water. Soak for 24 hours Specimens are weighed to g on an analytical balance 6

7 Bench-scale Indexed Performance Tests Developed to test the RECP/soil system under carefully controlled standard conditions, but on a scale that facilitates lower cost and quicker testing. Germination Enhancement Specimens are suspended under the analytical balance and weighed in water Slope Erosion Channel Erosion ROLLED EROSION CONTROL PRODUCTS (RECPs) Bench-scale Simulated Slope Testing ASTM D 7101 Temporary RECPs - For applications where natural vegetation alone will provide sufficient permanent erosion protection. Open Weave Textile (OWT). Erosion Control Blanket (ECB). Permanent RECPs - For applications where natural vegetation alone will not sustain expected flow conditions and/or provide sufficient long-term erosion protection. Turf reinforcement mat (TRM) Slope erosion: rain splash and runoff National Transportation Product Evaluation Program (NTPEP) Quality Assurance Testing Basic index tests (mass, thickness, etc.) for benchmarking the tested materials, assessing production variability, and facilitating correlations to performance. Bench-scale tests as indicators of system performance. Slope Testing - Sample Report Soil Loss Ratio* Based on Raw Data Rain Intensity, mm/hr SLR C-Factor RECP Erosion Control Product - Soil Loss vs. Intensity 3:1 Slope CONTROL RECP Expon. (CONTROL ) Expon. (RECP) Soil Loss (g) Rainfall Intensity (mm/hr) 7

8 Bench-scale Simulated Channel Testing ASTM D 7207 Germination Testing Sample Report Germination / Vegetation Growth Summary ECTC Test Method #4: STANDARD INDEX TEST METHOD FOR the DETERMINATION of TEMPORARY DEGRADABLE RECP PERFORMANCE IN ENCOURAGING SEED GERMINATION AND PLANT GROWTH Property Units Day Control RECP Seeds Germinated # per 4 sq.in per Area Average inch Plant Height Plant Mass mg per 4 sq.in per Area Property Units Day Control RECP Seeds % Improvement vs Germinated Control per Area % Channel erosion: hydraulic shear stress Average % Improvement vs. Plant Height Control Plant Mass % Improvement vs. per Area Control % % Channel Testing - Sample Report Shear Stress vs Soil Loss RECP ECTC Test Method #3: STANDARD INDEX TEST METHOD FOR the DETERMINATION of UNVEGETATED ROLLED EROSION CONTROL PRODUCT (RECP) ABILITY TO PROTECT SOIL FROM HYDRAULICALLY-INDUCED SHEAR STRESSES UNDER BENCH-SCALE CONDITIONS Sand only Comparing Available Performance Testing of RECPs Accurate comparisons are not possible when performance data is developed using different test procedures To remedy this situation, an increasing number of agencies are relying exclusively on standardized test procedures. Soil Loss (g) g = 1/2-in soil loss For example, in 2009 in the US, the National Transportation Product Evaluation Program began offering independently verified full-scale performance testing and providing this data to the public at Note: Shear stress raio = 2.10 / 0.1 = kpa 0.1 kpa kPa 0.2 4kPa Shear Stress (psf) Bench Scale Germination Testing ASTM D 7322 LARGE-SCALE TESTING OF EROSION CONTROL PRODUCTS ON SLOPES Standard Full-Scale Testing: ASTM D Standard Test Method for Determination of Rolled Erosion Control Product (RECP) Performance in Protecting Hillslopes from Rainfall-Induced Erosion. control Rainfall Intensities = 50, 100, minutes each; 1 control + 3 replicate slopes; Inclined (3:1) slopes, 12.2 m (40 ft) long and 2.4 m (8 ft) wide; Minimum 30 cm (12 in) compacted soil veneer; Simulated rain system with 4.3 m (14 ft) drop height & up to 150+ mm/hr capacity. Seed protection / germination enhancement 8

9 LARGE-SCALE TESTING OF EROSION CONTROL PRODUCTS ON SLOPES LARGE-SCALE TESTING OF EROSION CONTROL PRODUCTS IN CHANNELS ASTM D 6459 Slope Testing Facility (bare soil test shown) Testing of Rolled Erosion Control Products (RECPs) RECPs of All Types are Tested Vegetated Turf Reinforcement Mats (TRMs) Can Be Tested LARGE-SCALE TESTING OF EROSION CONTROL PRODUCTS IN CHANNELS Standard Full-Scale Testing: ASTM D Standard Test Method for Determination of Rolled Erosion Control Product (RECP) Performance in Protecting Earthen Channels from Stormwater-Induced Erosion. Rectangular (flume) with 10% (unvegetated) or 20% (vegetated) slope; Rectangular cross-section at least 0.6 m (2 ft) width and 0.6 m (2 ft) high side walls; 3 replicate test sections; Minimum 30 cm (12-inch) compacted soil veneer; Increasing Shear 30 minutes (unvegetated) or 1 hour (vegetated) each; ½-inch average soil loss failure criteria. NTPEP Performance Testing To-Date Product Type Key (most common types): 0NX = netless excelsior blanket; 1NX = single net excelsior blanket; 2NX = double net excelsior blanket; 1NS = single net straw blanket; 2NS = double net straw blanket; 2NSC = double net straw-coconut blanket; 2NC = double net coconut blanket; 2NFF = double net polyfiber matting; 3-D Woven = polymer yarn woven matting; OWM = open weave mesh Other Product Types Tested via NTPEP: 3NSC = triple net straw-coconut blanket; 3NC = triple net coconut blanket; 3NFF = triple net polyfiber matting; 2D Grid = 2-dimensional geogrid; Panel = scour resistant panel LARGE-SCALE TESTING OF EROSION CONTROL PRODUCTS IN CHANNELS Channels Tested in Triplicate Long-term Flows are Facilitated by Pumped Recirculation Test Series Evaluated ECBs and OWMs TRMs Product Type Test Category # of Tests Product Type Test Category # of Tests 0NX Index/Bench scale 3 Index/Bench scale 10 3D Woven Index/Bench scale 24 Large scale Channel 1 1NX Large scale Slope 2 Index/Bench scale 10 OWM Index/Bench scale 80 Large scale Slope 1 1NS Large scale Channel 4 Large scale Slope 10 Index/Bench scale 40 2NX Large scale Channel 4 Large scale Slope 1 Index/Bench scale 94 2NS Large scale Channel 9 Large scale Slope 13 Index/Bench scale 45 2NSC Large scale Channel 3 Large scale Slope 6 Index/Bench scale 54 2NC Large scale Channel 4 Large scale Slope 4 OWM Index/Bench scale 10 Large scale Slope 1 9

10 Possible Index, Bench-, and Large-scale Correlations Index Test D7101 Rainfall Bench-scale Test D7207 Shear R 2 D7322 Germination Large-scale Test D6459 Slope D6460 Channel Mass/Area, D Thickness, D Percent Cover, D Tensile (MD), D Absorption, D1117/ECTC Density, calculated Regression Equation using the calculated density C-Factor Allow. Shear = x + = x Germination = x C-Factor Allow. Shear = x + = x CONCLUSIONS A two decade effort by industry professionals has produced recognized, standardized tests for measuring relevant material properties as well as performance capabilities of RECPs. These now commonly used standardized index, benchscale, and large-scale tests for RECPs, are the basis for data from hundreds of independent tests performed on a range of RECPs under the auspices of the National Transportation Product Evaluation Program (NTPEP). An assessment of the relevance and correlation of the various tests, has facilitated recommendations on the appropriate use of these test results in specifications for RECPs. On-going independent performance testing of erosion control products will be posted at NTPEP Performance Testing To-Date Bench-scale C-Factor (ASTM D7101) Bench-scale Permissible Shear (ASTM D7207) Large-scale C-Factor (ASTM D6459) Large-scale Permissible Shear (ASTM D6460) C-Factor / Permissible Shear, psf C-Factor Multiplier Permissible Shear Multiplier Questions are welcome. Thank you for your interest. Presented by: C. J. (Joel) Sprague, TRI/Environmental, Inc., Greenville, SC J. E. (Jay) Sprague, TRI s Denver Downs Research Facility, Anderson, SC Logo here 0.00 OWM 0NX 1NX 2NX 1NS 2NS 2NSC 2NC 2NFF 3D Woven Possible Form of Standardized RECP Specifications RECP Classification Type 1 Type 2 Type 3 Type 4 Type 5 Type 6 Type 7 Typical RECP Type (for guidance only) 0NX, 1NX, 2NX, 2NS 2NSC 2NC 2NFF, 3D 2NFF, 3D 2NFF, 3D 1NS, OWM Ultra Short- Short-term Extended Term Long-Term Term Durability (for guidance only) TRM TRM TRM 3-6 mo mo mo. > 24 mos. C-Factor - ASTM D 6459 C 0.08 C 0.06 C 0.04 C 0.02 C 0.08 C 0.06 C 0.04 Max. Slope Max. Slope Gradient Permitted Use on Slopes (X) Length (ft) < 5:1 100 X X X X X X X 5:1 < 4:1 80 X X X X X X X 4:1 < 3:1 60 X X X X X X 3:1 < 2:1 40 X X X X X 2:1 < 1:1 20 X X X X Permissible Shear, Unvegetated ASTM D Permissible Shear, Fully Vegetated - ASTM D 6460 Not req d Not req d Not req d Not req d Tensile Strength (MD),lb/in ASTM D Tensile Elongation (MD),% ASTM D Tensile Strength (XD),lb/in ASTM D Tensile Elongation (XD),% ASTM D Mass / Unit Area, osy ASTM D Thickness, mils ASTM D Ground Cover, % ASTM D Water Abs, % (ECBs); SG (TRMs) ASTM D Bench-scale Slope, Avg SLR ASTM D Bench-scale Permissible Shear, psf ASTM D Bench-scale Germination, % Impr ASTM D UV Stability, % Retained at 500 hrs ASTM D4355 n/a n/a n/a n/a 80% 80% 80% Reports for large-scale testing must be provided from accredited QC Data testing must be provided with certification. Product must be listed at independent laboratory. 10