Establishing Blast Criteria

  • Primary use - to protect life, equipment or both.
  • Door configuration - swing, horizontal slide or vertical lift.
  • Opening size.
  • Blast door manufacturer must provide all critical components -- door panel, frame with anchorage and hinge (swing door), blast restraints (sliding door), and hardware.
  • Review wall construction - must be sufficient to withstand blast force and handle door weight.
  • Review reinforcements - blast and rebound reactions will be transferred to frame and frame anchors, or blast restraints, and capable of transferring load to adjacent wall or structural sub-frame embedments.
  • Type of explosive - solid, liquid or gas - ammunition, bomb, missile, chemical, nuclear, steam pressure, etc.
  • Other hazards to be controlled - fire, smoke, gas fumes, ballistics, fragment resistance.
  • Blast force - either PSF (pounds per square foot) or PSI (pounds per square inch).
  • Static or dynamic analysis.
    • Static equivalent load:
      1. Maximum amount of blast force the door system will be subjected to.
      2. Rebound - this is a negative suction phase at initial peak response and expressed as a percentage of reflected pressure (normally 100%).
    •  Dynamic analysis:
      1. Amount of blast force the door will be subjected to at Pr peak reflected pressure.
      2. Duration of the positive phase (stated in milliseconds - ms.)
      3. Rebound shall be as calculated by the blast analysis.
      4. Angle of incidence - if unknown, assume 0° which shall give the maximum protection.
      5. Maximum ductility ratio (µ) of 1 (if elastic) or greater than 1 (if plastic).
      6. The door edge support rotation shall not exceed ___° (degrees).
  • Direction of initial blast force - either seating (into frame) or unseating direction (against hardware).
  • Plastic or elastic deformation.
    • Elastic - The allowable elastic deflection is limited to L/60, L/120 or L/240 of the span. If the doors will be subjected to repetitive blasts, then no permanent deformation shall be allowed.
    • Plastic (unavailable for static design) - door system contains the blast force but allowed to deform in the opening.
  • Fire Label requirements.
  • Interior or exterior application.
  • Door operation - manual or power operation, frequency of use, etc.
  • Hardware requirements - lever handles, panic bar, access control, door closer (required for Fire Label), weatherstripping, door bottom, threshold.

Additional notes:

Use of galvanized material is not compatible with all-welded steel door construction. Hold-open devices are discouraged on a blast resistant door. When not in use, the door must remain closed at all times.