1. THE BUILDING ENVELOPE: Lecture 6 Analysis of Debris Loads

2. DEBRIS LOADS: PHYSICS Large Missiles: Timbers, roof tiles, sheet metal, bricks Fly or tumble near ground Impact speed 1/3 to 1/2 of V Small Missiles: Roof gravel, glass particles, Fly at rooftop elevations Impact speed 90% of V

3. ASTM STANDARD E1886-02 (TEST METHOD) Large missile: 4.5 - 15 lb 2x4 timber impacting between 0.10 and 0.55 of the basic wind speed (3-sec gust) Small missile: solid steel ball having a mass of 2 gm impacting between 0.40 and 0.75 of the basic wind speed (3-sec gust)

4. DEBRIS IMPACT PROVISIONS IN ASCE 7-02 Hurricane prone regions Wind borne debris regions Glazing, impact resistant Impact resistant covering

5. ASTM STANDARD E1996- 02 (SPECIFICATION)

6. IMPACT TEST PROTOCOL Impact with representative missile –large missile (2x4 timber) –small missile (2 gm steel ball or rock) Apply fluctuating pressures –inward acting –outward acting

7. FLUCTUATING PRESSURES IN U.S. CODES AND STANDARDS

8. U.S. CODES AND STANDARDS WITH DEBRIS IMPACT PROVISIONS ASCE 7-02 International Building Code International Residential Code Florida Building Code TWIA Building Code ASTM E1886/1996

9. GLAZED OPENING DESIGNS FOR WINDBORNE DEBRIS

10. TYPICAL GLAZING SYSTEM DESIGNS THAT MEET IMPACT STANDARD

15. SHUTTER SYSTEMS THAT MEET IMPACT STANDARD

17. PRODUCT APPROVALS Dade County (Florida) Office of Code Compliance Texas Department of Insurance ICC Product Evaluations

18. WINDBORNE DEBRIS: RISK MODEL