FIRE ENDURANCE OF CONCRETE FLOORS WITH EMBEDDED ELECTRICAL UNDERFLOOR DUCTS

THE RESULTS ARE PRESENTED OF FIRE TESTS OF 35 PILOT SPECIMENS (3X3 FT) AND TWO FULL-SCALE FLOOR SPECIMENS (14X18 FT). IN THE PILOT TESTS, ONE LEVEL OF DUCTS WAS EMBEDDED IN SLABS 5-, 6-, AND 7-IN. THICK, AND TWO LEVELS OF DUCTS IN SLABS 7-, 8.5-, AND 10-IN. THICK. FULL-SCALE SPECIMENS WERE PAN-JOIST FLOORS IN WHICH THE SLAB WAS THICKENED 1.5 IN. IN THE AREA WHERE TWO LEVELS OF DUCTS WERE USED. NOMINAL SLAB THICKNESSES WERE 5 AND 5.5 IN. THE DUCTS CAUSED NO VISIBLE STRUCTURAL DISTRESS DURING THE FIRE TESTS. FIRE ENDURANCE WAS GOVERNED BY THE TEMPERATURE RISE OF THE UNEXPOSED SURFACE. WHERE ONE LEVEL OF DUCTS IS USED (WITHOUT JUNCTION BOXES), SLAB THICKNESSES OF AT LEAST 5.3 AND 6.6 IN. ARE REQUIRED FOR 2- AND 3-HR FIRE ENDURANCE. FOR TWO LEVELS WITH JUNCTION BOXES, SLAB THICKNESS REQUIREMENTS ARE APPROXIMATELY 6.5 AND 7.5 IN. FOR 2- AND 3-HR FIRE ENDURANCE. ENDURANCE PERIODS WERE SLIGHTLY GREATER FOR LIGHTWEIGHT CONCRETE, OR IF DUCTS CONTAINED WIRES DURING FIRE TESTS. /PCA/

• Authors:
  • Abrams, M S
  • Gustaferro, A H
• Publication Date: 0

Media Info

• Serial:
  • Portland Cement Assoc R & D Lab Bull
  • Issue Number: 0

Subject/Index Terms

• TRT Terms: Anchoring; Concrete; Conduits; Electrical wiring; Fire resistance; Fires; Floors; Lightweight concrete; Slabs; Specimens; Thickness
• Old TRIS Terms: Electrical conduits; Embedments (Concrete); Full scale specimens; Test results
• Subject Areas: Highways; Materials;

Filing Info

• Accession Number: 00213649
• Record Type: Publication
• Source Agency: Portland Cement Association
• Report/Paper Numbers: No 216
• Files: TRIS
• Created Date: Jun 1 1970 12:00AM