More E The test specimens shall be Fenestration assemblies, and impact protective systems; which shall be tested using the large missile test, and small missile test. The air pressure cycling, missiles, and impact location are also detailed. This abstract is a brief summary of the referenced standard.
|Country:||Antigua & Barbuda|
|Published (Last):||23 August 2014|
|PDF File Size:||7.97 Mb|
|ePub File Size:||3.23 Mb|
|Price:||Free* [*Free Regsitration Required]|
More E Design pressures based on wind speeds with a mean recurrence interval usually 25 to years that relates to desired levels of structural reliability and are appropriate for the type and importance of the building 1. However, these test methods do not account for other factors such as impact from windborne debris followed by fluctuating pressures associated with a severe windstorm environment. As demonstrated by windstorm damage investigations, windborne debris is present in hurricanes and has caused a significant amount of damage to building envelopes The actual in-service performance of fenestration assemblies and impact protective systems in areas prone to severe windstorms is dependent on many factors.
Windstorm damage investigations have shown that the effects of windborne debris, followed by the effects of repeated or cyclic wind loading, were a major factor in building damage The resistance of fenestration or impact protective systems assemblies to wind loading after impact depends upon product design, installation, load magnitude, duration, and repetition. The damage caused by windborne debris during windstorms goes beyond failure of building envelope components such as windows, doors, and curtain walls.
A potentially more serious result is internal pressurization. When the windward wall of a building is breached, the internal pressure in the building increases, resulting in increased outward acting pressure on the other walls and the roof.
This can increase the net outward acting pressure by a factor as high as two. For example, if window glass is likely to be broken by missiles during a windstorm, this is considered to be an opening. However, if doors and windows and their supports are designed to resist specified loads and the glass is protected by a screen or barrier, they need not be considered openings. The latter approach reduces the likelihood of exposing the building contents to the weather.
Typical debris in hurricanes consists of missiles including, but not limited to, roof gravel, roof tiles, signage, portions of damaged structures, framing lumber, roofing materials, and sheet metal 4, 7, 9. The missiles and their associated velocity ranges used in this test method are selected to reasonably represent typical debris produced by windstorms.
Superimposed on the averaged winds are gusts whose aggregation, for short periods of time ranging from fractions of seconds to a few seconds may move at considerably higher speeds than the averaged winds.
Wind pressures related to building design, wind intensity versus duration, frequency of occurrence, and other factors are considered. It is appropriate to test the strength of the assembly for a time duration representative of sustained winds and gusts in a windstorm. Gust wind loads are of relatively short duration. They are not to be specified for the purpose of testing the adequacy of the assembly to remain unbreached in a windstorm environment following impact by windborne debris.
Scope 1. A missile propulsion device, an air pressure system, and a test chamber are used to model some conditions which may be representative of windborne debris and pressures in a windstorm environment. This test method is applicable to the design of entire fenestration or impact protection systems assemblies and their installation.
The performance determined by this test method relates to the ability of elements of the building envelope to remain unbreached during a windstorm. The values given in parentheses after SI units are provided for information only and are not considered standard. Certain values contained in reference documents cited herein may be stated in inch-pound units and must be converted by the user.
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.
Specific hazard statements are given in Section 7.
Missile Impact Test Demonstration Video – ASTM E1886 and TAS 201
ASTM E1996 Missile Levels and Definition