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H-20/M-18 (AASHTO) Based on standardized mathematical calculations, derived from testing data reported by BECETEL (Belgian Research Centre for Pipes and Fittings) on December 8th , 2005, and Translated on April 20, 2006 (attached), and supported by DIN-Compliance Certification reported by TUV 27 July 2006 (attached). The German Manufactured Products "101 E-50" and "101 S-50" (branded in Germany and most of Europe as “ecoraster®” and in some English-language nations not including the USA as "ecogrid®") meet and exceed the H-20/M-18 AASHTO standard. Please find below calculations which apply the known physical characteristics of the product, in demonstrating the product exceeds the American AASHTO standard known as "H-20 Loading" (or "M-18 loading" in reference to metric tonnes). [ TOP ]
Section 1. Defining the Standard (American) Paragraph 1. The American Association of State Highway Transportation Officials (AASHTO) has established an H-20 loading as being a reference to 36,000 pounds. Paragraph 2. Using these guidelines, this weight would be distributed over the front and rear axles of the truck resulting in 20% of the weight on the front axle and the remaining weight, or 80% of the total, realized on the rear. Paragraph 3. Vehicles of this type usually are supported by two tires in the front, and by at least four tires (single axle) or eight tires (tandem axle) in the rear. Paragraph 4. Summary: According to the weight distribution cited above (Section 1, paragraphs 2 and 3) It is determined that the front tires would be supporting 3,600 pounds and that the maximum load being supported by the rear tires would be 7,200 pounds each (for four tire rear Load) or 3,600 pounds each (eight tire rear load). [ TOP ]
Calculations: FRONT LOAD DISTRIBUTION = (36,000 lbs.) * (20%) = 7,2000 lbs. REAR LOAD DISTRIBUTION = (36,000 lbs.) * (80%) = 28,800 lbs. FRONT TIRE LOAD: [steering] Two tires: (7,2000 lbs.) / (2 tires) = 3,600 lbs./tire REAR TIRE LOAD: [for either single-axle or dual-axle truck rear load configurations] Single-axle/Four Tires: (28,800 lbs.) / (4 tires) = 7,200 lbs./tire Dual-axle/Eight Tires: (28,800 lbs.) / (8 tires) = 3,600 lbs./tire [ TOP ]
Section 2. Determining the footprint of the prescribed tandem-axle or single-axle vehicle's tires. Paragraph 1. GIVEN: It is assumed that all tires are equal in size. Paragraph 2. FIELD MEASURE: A field measurement of an H-20 vehicle tire, under load, created a footprint of approximately 6.5" Wide by 8" Long - this is the standard. This footprint produces a planar area of 0.36111 ft²/tire, over which the specified 36,000 lbs. must be distributed. [ TOP ]
Section 3. Determining the load/tire requirement. Paragraph 1. Front and Rear Tire Loads calculations: FRONT STEERING/TWO TIRE configuration: Two tires: (3,600 lbs./tire) / ( 0.36111 ft2/tire) = 9,969.261 lbs. / ft2 REAR SINGLE-AXLE/FOUR TIRE configuration: Four Tires: (7,200 lbs./tire) / ( 0.36111 ft2/tire) = 19,938.523 lbs. / ft2 REAR DUAL-AXLE/EIGHT TIRE configuration: Eight Tires: (3,600 lbs./tire) / ( 0.36111 ft2/tire) = 9,969.261 lbs. / ft² [ TOP ]
Section 4. Applying known physical characteristics. Paragraph 1. Determining the known physical characteristics. The BECETEL testing of 25 April 2006, Report number 7384, Section 2.2.2, resulted in a compressive strength (resistance to pressure at the surface): MEAN value of 99.9 kN with a standard deviation of no more than 1.5 kN. Paragraph 2. Applying the known physical characteristics to the formulaic standard. Conversion of scientific units of force (kN) into American (British) Standard Units of "weight" (foot-pounds at standard atmospheric pressure at sea level under standard gravity conditions); and conversion into common Weight/Area terminology: The compressive Strength = 99.9 kN (op. cit. BECETEL, sect. 2.2.2) Therefore, compressive strength is: (224.81 pounds / kilonewton) * (99.9 kilonewton) = 22,458.519 pounds Size of Anvil defined: "a steel anvil of 250 mm diameter" [NOTE: this value is determined from the accompanying description of the test apparatus.] Radius of the anvil: 0.125 meters Rate of Acceleration (rate of increasing incremental force) : Fmax Acceleration = 40mm/min Area of Anvil = pr² = (3.1415926535897932384626433832795) * (0.125m) = (3.1415926535897932384626433832795) * (0.015625)m2 = 0.049087385212340519350978802863742 m² Conversion of Metric into British units of Measure, formula: 1.0 m2 / 10.7639104167 ft² = (0.049087385212340519350978802863742 m²) I (1.0 m2 / 10.7639104167 ft²) = 0.52837221701567765762948865947794 ft² Therefore, the LOAD/AREA = (22,458.519 pounds) I (0.52837221701567765762948865947794 ft²) = 42505.109611646403891074991939166 pounds / ft² OR: "over 21 US tons /square foot" Duplicating the above in American (British) units: Anvil = 0.125m radius = 0.41010416667 ft radius Area of Anvil = = pr² = p(0.41010416667 ft)² = p (0.1681854275200951388889)ft² = 0.52837010353798952615368392049125 ft² Therefore, the LOAD/AREA: = (11.23 US Tons) / (0.52837010353798952615368392049125 ft²) = 21.254041295681615041124720269256 tons / ft² OR: "over 21 US tons /square foot" Subsequent Laboratory Testing Results: Resistance to Pressure at the Surface ("compressive strength") In excess of 350,000 kg/m² = In excess of 70,000 lbs. / ft² = In excess of 35 tons / ft² [US short tons - avdp] [ TOP ]
Conclusion: The BECETEL testing of 25 April 2006 indicates that the compressive strength of the product ecoraster® E-50 bearing the maker's mark "101 E 50" [source = http://www.ecoraster.us/media/pdf/documentation_studies_test-results/BECETEL_laboratory-test-results_ecoraster_porous_elements.pdf ] (1) are:  (i) considerably exceeding the AASHTO H20/M18 standard, at 70,000 psf, unfilled. (ii) and thus more than capable of supporting a comparable H-20/M-18 loading, when installed to manufacturer's specifications. (2) This concurs with the certification performed by TUV/Nord on 5 October 2006 ... Registered Certificate Number: 44 781 06 336388 Certificate confirms compliance with: DIN 1072:1985 Which certificate of compliance states and attests to meeting the Vehiclular LOAD standard of:  20 Metric Tons per each vehicle axle With an expected lifespan of: indefinite/unlimited [please note: the 20MT/axle standard above derives from the the maximum rating for vehicles commonly allowed on public streets and roadways, is also the maximum TS&W allowed on public vehicular traffic surfaces in Germany and the EU, applicable to both roads and bridges, for either vehicular or pedestrian traffic. Compliance with this 20MT/axle standard does not imply or infer that a higher standard could/would not be exceeded by the ecoraster® E-50 product, if such a higher standard were to exist. = the 20MT/axle standard is the highest norming available for public roadways and bridges, per DIN 1072:1985.] [ed. All mathematical conversions + calculations, as well as any applications of standard S.I./en international scientific convention norming herein are provided by m. rector (not a professional typist). If any typographicalmistakes/errata are found, please notify us.] [ TOP ]