Joseph E. Minor

Windborne debris and the building envelope

Twenty-three years of documented windstorm damage experiences illustrate the importance of protecting the building envelope from windborne debris and fluctuating pressures that occur during windstorm events. A 2 × 4 timber and roof gravel are defined as representative objects for use in standard tests to qualify products for use in the building envelope. A 9000 cycle pressure spectrum that represents fluctuating pressures which occur in a hurricane is also specified for product qualification tests. The evolution of these test standards is traced and building codes that have adopted these criteria are referenced. Current design practices that are responsive to these windstorm effects and standard tests are described. Windows and architectural glazing systems that can protect openings in the building envelope from being breached by windborne debris are illustrated.

Post-breakage behavior of architectural glazing in Windstorms

Abstract The selection of architectural glazing products for use in tall buildings has evolved into a complex process in a relatively short period of time. Many new factors have to be considered in the design procedure, and the array of new available products has created unlimited design choices. Among the new design considerations are missile impacts and the behavior of glass after breakage in a windstorm. Post-breakage behavior is described, principally, in terms of resistance to small missile impact, glass particle fallout and the propensity of glass panels to remain in the frame. These behavioral characteristics are directly related to hazards to people and a desire to protect the building and its interior furnishings and equipment from the effects of windstorms.

A simple window glass design chart

Abstract A recently published ASTM standard outlines procedures for determining the strength of glass products used in buildings as windows and cladding. The new standard uses structural mechanics relationships to define the strength of a wide range of products, including monolithic glass, laminated glass and insulating glass. While the new standard is thorough and accurate, it is also complex. The authors offer a simple approach to the design of these glass products that applies to most building conditions, leaving only the exceptions to be treated by the complex process.