Peter D' DiMaggio, PE

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Blast Resistant Design Using Advanced Materials

• Peter D. DiMaggio, PE
• Matthew J. Kmetz, PE
• Weidlinger Associates, Inc.
• For
• 2008 Structures Congress
• Vancouver, British Columbia
• April 25, 2008
• Special Thanks to
• EXCEND
• Royal Building Technologies

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Terrorist Attacks Technology TimelineIncreased
Threat Increased Mitigation
Major Recent Events
Technical Advances
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Major Advances in Technical Capability

• Threat Side CFD
• Analysis side Advanced Computational Techniques
• Testing Side Increased Ability to Simulate
  Loading

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We Need to Continue to Improve
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Material Advances

• Analytical Advances - Evolutionary
• Steady advances over the last 10 years
• Material Advances Not as successful
• Recent surge in promising new materials

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Overview

• Types of Materials and their applications
• Several promising new products
• Major challenges
• Testing and analysis programs
• Where do we go from here?

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Current Practice

• Significant progress glazed facades
• Advanced Laminates
• Structural Silicones
• Energy Absorbing Mullions
• Use of High End Analysis
• Creative Mullion Anchorages
• Lessons Learned From Testing
• Non Glazed Facades lagging

Computer Model
Blast Test
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Exterior Wall Systems Current Practice

• Advanced Glazing Anchored to conventional wall
  system
• Steel Studs
• Precast Concrete
• Reinforced Masonry
• Cast-In-Place Concrete
• Large market for cost effective blast resistant
  facades
• Need is real

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Examples

• Energy Absorbing Windows in Precast Facades

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Recent Advances

• DUCON Slurry Infiltrated Micro-Reinforced
  concrete
• Royal Building Systems (RBS) finished concrete
  wall system
• Not an exhaustive list
• Highlight promising new materials
• Most interested in what we can learn from our
  experiences with these materials

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DUCON Material Properties

• SLIMR
• Very thin mats of wire mesh
• High strength slurry

Images Courtesy of EXCEND
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DUCON Advantages

• Advantages
• Very ductile behavior
• High quality finishes
• Produced in very thin sections (25 mm)

Images Courtesy of EXCEND
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DUCON Blast Protection

• Preliminary testing vey positive for near contact
  charges
• Greatest challenge is stiffness
• Not a significant issue in a blast application
• Cutting edge technology potential reduction in
  blast wall thicknesses

Images Courtesy of EXCEND
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RBS Material Properties
Insulation
Concrete

• Stay in Place PVC concrete forming system
  Patented Forming Technology
• Rigid polymer components that serve as concrete
  formwork
• PVC forms
• Reinforcement
• Insulation
• Concrete

Polymer Shell
Reinforcing Bar
Images Courtesy of RBS
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RBS - Advantages

• Advantages
• Ease of Construction certain structures
• Appears to have inherent blast resistant capacity

Images Courtesy of RBS
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RBS Blast Protection

• Preliminary testing and analysis very positive
• PVC adds strength
• PVC adds stiffness reduces deflection
• Reduces spall

Images Courtesy of RBS
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Industry Challenges

• Process of bringing these materials to market
• Demonstrate Effectiveness to Engineers
• Inform the Architectural Community
• Aesthetic and Environmental qualities
• Convince the Building Officials
• Our experience is that this is
• Expensive
• Time Consuming

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Industry Challenges 2

• Cost must be borne by manufacturer
• Necessary for Design Firms to Specify Material
• Research must be done PRIOR to project
  application
• Industry Model Airline Industry and Composite
  Technology

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Testing and Analysis

• Physical Testing
• Demonstrate material effectiveness
• Too costly to test for all variations
• Test Program in Concert with Analytical Work
• Analysis Verify test results / develop
  procedure
• Advanced Modeling critical for new materials
• Simplified SDOF models Design Tool
• Imperative if product use is to be widespread

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Example of Advanced Analysis
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Summary and Conclusions

• Time is Right for advanced materials to be used
  in buildings
• Especially with regard to building facades
• Several promising examples available now
• Industry challenges are great
• Well financed, well thought out approach has the
  potential to return great rewards
• Airline Industry Composites

Composite Aircraft by Boeing