Masonry Performance and the WTC

Building Safety Journal (September 2003), Masonry Performance and the World Trade Center Disaster, discusses a new report by The Masonry Society, Masonry Aspects of the World Trade Center Disaster. The report evaluates the performance of buildings with masonry construction surrounding the twin towers during the WTC event. Conclusions appear to reflect favorably on masonry's greater mass and durability in comparison to other materials. For example:

• Framed buildings with exterior masonry walls generally performed better than newer buildings with lighter, curtainwall construction
• Masonry infill for walls and beams provided significant fire protection
• Masonry infill provided alternate load paths where columns were damaged, in some cases preventing partial structural collapse
• Interior masonry partitions provided redundant lateral force resistance
• Masonry flat arch floors built to early 20th standards provided better fire protection than newer steel framed construction.