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5.1 The air permeability of roofing systems constructed from discrete elements, as is the case for clay and concrete tile and slate roof systems, is a critical factor in determining the wind resistance of the roof system. The ability of the roof system to relieve wind-induced uplift pressures as a result of the overall air permeability of the roof assembly relates to the resistance of the roof system to damage induced by wind.5.2 Natural wind conditions differ with respect to intensity, duration, and turbulence; these conditions are beyond the means of this test method to simulate.1.1 The air permeability of tile roofing systems is a critical factor in determining the wind resistance of tile roofing as applied to a roof. This Standard describes a procedure for measuring the air permeability of clay and concrete tile and slate roof systems when applied to a small section of roof deck in accordance with the manufacturer's instructions.1.2 This test procedure measures the air permeability of a laid array of unsealed clay or concrete roof tiles or slates. The tiles or slates shall have a thickness between 1/8-in. (3-mm) and 2-in. (51-mm).1.3 The text of this test method references notes and footnotes, which provide explanatory material. These notes and footnotes (excluding those in tables and figures) shall not be considered as requirements of the standard.1.4 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical conversions to SI units that are provided for information only and are not considered standard.1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.1.6 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

定价: 515 加购物车

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6.1 The wind resistance of sealed asphalt shingles is directly related to the ability of the sealed shingle to resist the force of the wind acting to lift the shingle from the shingle below. This test method employs the measured resistance of the shingle to mechanical uplift after sealing under defined conditions, in a calculation which determines whether this resistance exceeds the calculated force induced by wind passing over the surface of the shingle. Natural wind conditions differ with respect to intensity, duration, and turbulence; while these conditions were considered, and assumptions that specify higher than actual loads are used, extreme natural variations are beyond the means of this test method to simulate.6.2 Many factors influence the sealing characteristics of shingles in the field; for example, temperature, time, roof slope, contamination by dirt and debris, and fasteners that are misaligned or under driven and interfere with sealing. It is beyond the scope of this test method to address all of these influences. The classification determined in this test method is based on the mechanical uplift resistance determined when representative samples of shingles are sealed under defined conditions before testing.6.3 The calculations that support the classes in 4.1 apply to buildings of any risk category and any roof slope where all of the following conditions are applicable:(1) The ASCE 7-22 mapped basic wind speed (3 s gust) for a given building risk category does not exceed the wind speed associated with the applicable shingle class in Section 4,(2) The wind exposure category is B or C,(3) The mean roof height does not exceed 60 ft, and(4) There are no topographic wind speed-up effects.NOTE 4: The assumptions used in the calculations for the classes in 4.1 cover the requirements for the majority of the asphalt shingle roofs installed. If environmental factors are outside those listed above as used in the calculations for these classes, other calculations are required to determine the required shingle class based on project-specific conditions; refer to Appendix X1 for additional information and calculation examples. Consult the shingle manufacturer for the specific shingle’s DCp, EI, L, L1, and L2 values needed to complete these calculations.NOTE 5: Additional engineering consideration is necessary to verify acceptability of asphalt shingles classified in accordance with this standard for use on Category III and IV buildings for either of the following conditions: (1) geographic areas in which the ASCE 7-22 basic wind speed exceeds 312 km/h [194 mph], or (2) project sites within the “tornado prone region” and determined to require design for tornado loads in accordance with Chapter 32 of ASCE 7-22.6.4 The test to determine uplift coefficients is conducted with a wind velocity of 15.6 ± 1.3 m/s [35 ± 3 mph]. Research data obtained during the development of this test procedure, as well as standard wind modeling practices, provides for data extrapolation to other wind speeds. In order to simulate the raised shingle edge that is inherent behavior under high wind exposure, shims are inserted under the windward edge of the shingle as appropriate based on wind speed and uplift rigidity of the shingle being investigated. This test method provides a means of measuring shingle uplift rigidity which is used to determine the correct shim thickness. Additionally, this test method allows for the use of a default value for uplift rigidity (EI) of 7175 N-mm2 [2.5 lbf-in.2], if a rigidity measurement is not made. This default value is conservative since the lowest EI measured in the development of this program was 14 350 N-mm2 [5.0 lbf-in.2].NOTE 6: The entire field of wind engineering is based on use of small-scale models in wind tunnels using wind speeds much lower than the full-scale values. Building Codes permit testing of this type to replace the analytical provisions of the Building Code through the provisions of ASCE 7-22. (See Appendix X1 for details and references.)1.1 This test method covers the procedure for calculating the wind resistance of asphalt shingles when applied in accordance with the manufacturer's instructions and sealed under defined conditions. Shingle designs that depend on interlocking or product rigidity to resist the wind cannot be evaluated using this test method. The method calculates the uplift force exerted on the shingle by the action of wind at specified conditions, and compares that to the mechanical uplift resistance of the shingle. A shingle is determined to be wind resistant at a specified basic wind speed for standard conditions (see 6.3) when the measured uplift resistance exceeds the calculated uplift force for that velocity (3 s gust, ASCE 7).1.2 The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in each system may not be exact equivalents; therefore, each system shall be used independently of the other. Combining values from the two systems may result in nonconformance with the standard.1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.1.4 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

定价: 646 加购物车

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5.1 Most steep slope roofing products that have demonstrated wind resistance by this test have also performed well in use. Natural wind conditions differ with respect to intensity, duration, and turbulence; these conditions are beyond the means of this test to simulate. The results of this test do not directly correlate to wind speeds experienced in service, and no accommodation is made in this test method for building height, building exposure category, or building importance factor.5.2 Many factors influence the wind resistance of a steep slope roofing product in the field; for example, temperature, time, roof slope, contamination by dirt and debris, and fasteners, both appropriate and inappropriate, that are misaligned or misplaced, or over- or under-driven, and sealant adhesion, if used and functioning. It is beyond the scope of this test method to address all of these influences. This test method is designed to evaluate the wind resistance of products as described in the scope when representative samples are applied to test panels in accordance with the manufacturer’s instructions and conditioned as specified before testing.1.1 This test method covers the procedure for evaluating the wind resistance of many discontinuous, air permeable, steep slope roofing products that results from the product's rigidity, with or without contribution from sealant to help hold down the leading edge of the tabs, or mechanical interlocking, with or without contribution from sealant to help hold down the leading edge of the tabs, or any combination thereof. The products are applied to a test panel in accordance with the manufacturer’s instructions and tested at a 2:12 (17 %) slope, or at the lowest slope permitted by those instructions.1.2 This method evaluates wind resistance using a fan-induced procedure, delivering a stream of air across the exposed surface of the test specimens. This method does not measure structural performance, and does not provide a measure of uplift resistance. Consequently, this method is not applicable to continuous, non-permeable roof systems or coverings (such as membranes or mechanically seamed metal roof panels).1.3 This test method was formerly titled “Wind Resistance of Asphalt Shingles (Fan-Induced Method)” but was revised to acknowledge that the method is applicable to many other steep slope roofing products and has been used to evaluate the wind resistance of those products for many years by several testing and certification laboratories. Steep slope roofing products that fall under the scope of this test method, in addition to asphalt shingles, are polymer-based shingles, fiber-cement shingles, concrete tiles, clay tiles, metal shingles, and photovoltaic shingles.1.4 This test method is limited to steep slope roofing product applied with a maximum exposure of 410 mm [16 in.].1.5 The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in each system may not be exact equivalents; therefore, each system shall be used independently of the other. Combining values from the two systems may result in nonconformance with the standard.1.6 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.1.7 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

定价: 515 加购物车

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4.1 The method of attachment of roof tiles to the roof deck, or support structure, is one factor in the resistance of concrete and clay roof tiles to the action of wind. Several systems of attachment, and even combinations of systems, are used in the application of tile to a roof. The mechanical uplift resistance of the tile, when applied to the roof by any attachment system approved by, and in accordance with, the manufacturer's instructions, is a primary factor in the tile's resistance to the action of wind. This test method determines the mechanical uplift resistance that is related to resistance to the uplift forces acting as a result of wind. Natural wind conditions differ with respect to intensity, duration, and turbulence; these conditions are beyond the means of this test method to simulate.1.1 This test method covers a procedure to determine the mechanical uplift resistance of concrete and clay roof tiles, which relates to the wind resistance of an air-permeable roof tile system as applied to a roof.1.2 The procedure covers mechanically-fastened attachment systems, adhesive-set attachment systems, and mortar-set attachment systems, or combinations of attachment systems, that are used to apply tile to a roof.1.3 The values stated in inch pound units are to be regarded as the standard. The values in parentheses are given for reference only.1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.1.5 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

定价: 590 加购物车

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5.1 This guide provides a means of using an LD instrument to obtain a droplet size distribution from a spray in gas co-flow that approximates a flux-sensitive sample.45.2 In many sprays, the experimenter shall account for spatial segregation of droplets by size. This guide provides a means of spatial averaging the droplet distribution.5.3 The results obtained will be statistical in nature and refer to the time average of droplet size distribution of the entire spray.5.4 This guide is used to calibrate a spray generation device to produce a desired droplet size distribution under prespecified environmental and co-flow conditions or characterize an unknown spray while minimizing the uncertainty in the measurement.1.1 The purpose of this guide is to define a test procedure for applying the laser diffraction (LD) method to estimate an average droplet size distribution that characterizes the flux of liquid droplets produced by a specified spray generation device under specified gas co-flow conditions using a specified liquid. The intended scope is limited to artificially generated sprays with high speed co-flow. The droplets are assumed to be in the size range of 1 to 2000 µm in diameter and occur in sprays that are contained within a volume as small as a few cubic centimetres or as large as a cubic metre. The droplet sizes are assumed to be distributed non-uniformly within the spray volume.1.2 This guide is intended primarily to guide measurement of performance of nozzles and atomizers using LD instruments.1.3 Non-uniform sprays require measurements across the entire spray cross section or through several chords providing a representative sample of the overall spray cross section. The aim of multiple-chord measurements is to obtain a single droplet size distribution that characterizes the whole spray rather than values from a single chordal measurement.1.4 Use of this guide requires that the instrument does not interfere with spray production and does not significantly impinge upon or disturb the co-flow of gas and the spray. This technique is, therefore, considered non-intrusive.1.5 The computation of droplet size distributions from the light-scattering distributions is done using Mie scattering theory or Fraunhofer diffraction approximation. The use of Mie theory accounts for light refracted through the droplet and there is a specific requirement for knowledge of both real (refractive) and imaginary (absorptive) components of the complex index of refraction. Mie theory also relies on an assumption of droplet homogeneity. The Fraunhofer diffraction approximation does not account for light refracted through the droplet and does not require knowledge of the index of refraction.1.6 The instruments shall include data-processing capabilities to convert the LD scattering intensities into droplet size distribution parameters in accordance with Practice E799 and Test Method E1260.1.7 The spray is visible and accessible to the collimated beam produced by the transmitter optics of the LD instrument. The shape and size of the spray shall be contained within the working distance of the LD system optics as specified by the instrument manufacturer.1.8 The size range of the LD optic should be appropriate to the spray generation device under study. For example, the upper bound of the smallest droplet size class reported by the instrument shall be not more than 1/4 the size of DV0.1.1.9 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.1.10 This standard may involve hazardous materials, operations, and equipment. This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.1.11 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

定价: 590 加购物车

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