ESTIMATING POST-FIRE STRENGTH AND EXPOSURE TEMPERATURE OF PRESTRESSING STEEL BY A METALLOGRAPHIC METHOD

A METHOD IS PRESENTED WHICH USES METALLOGRAPHIC PROPERTIES OF COLD-DRAWN PRESTRESSING STEEL TO ESTIMATE EXPOSURE TEMPERATURES AND RESIDUAL TENSILE STRENGTHS. SPECIMENS OF PRESTRESSING STEEL STRAND WERE EXPOSED TO VARIOUS TEMPERATURES BETWEEN 70 AND 1500 F. AFTER COOLING TO 70 F, TESTS WERE CONDUCTED FOR TENSILE STRENGTH AND MICROHARDNESS, AND THE MICROSTRUCTURE WAS STUDIED. RELATIONSHIPS CORRELATING MICROHARDNESS, TENSILE STRENGTH, EXPOSURE TEMPERATURE, AND MICROSTRUCTURE WERE ESTABLISHED. THE METALLOGRAPHIC DATA WERE USED TO ESTIMATE THE EXPOSURE TEMPERATURES AND RESIDUAL TENSILE STRENGTHS OF 32 SPECIMENS OF STEEL RECOVERED FROM CONCRETE ELEMENTS EXPOSED TO ELEVATED TEMPERATURES FOR VARYING PERIODS OF TIME. THE ESTIMATED VALUES AGREED REASONABLY WELL WITH THE ACTUAL STRENGTHS AND TEMPERATURES, THUS INDICATING THAT THE METHOD IS APPLICABLE FOR POST-FIRE INVESTIGATIONS. /PCA/

• Authors:
  • Abrams, M S
  • Erlin, B
• Publication Date: 0

Media Info

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

Subject/Index Terms

• TRT Terms: Crash exposure; Fire resistance; Metallography; Microstructure; Prestressing; Steel; Temperature; Tensile strength
• Uncontrolled Terms: Exposure
• Subject Areas: Highways; Materials; Safety and Human Factors;

Filing Info

• Accession Number: 00213652
• Record Type: Publication
• Source Agency: Portland Cement Association
• Report/Paper Numbers: No 219
• Files: TRIS
• Created Date: Jun 1 1970 12:00AM