** DRAFT FOR PUBLIC COMMENT (for Final Version see NIST TN 1681) ** This document is intended to provide practicing engineers and building code officials with a technical resource that contains the current best practice for fire-resistant design of concrete and steel structures. The report provides a review of existing U.S. and international guidelines and design standards, which use approaches that range from simple prescriptive methods to sophisticated software programs with advanced methods of analysis under a wide range of realistic fire conditions. Basic concepts of risk-informed decision making for mitigating fire risk, and a general framework for assessing fire risk to building construction and for developing structural design requirements for fire conditions are described. Current best knowledge in thermal and mechanical properties and behaviors of normal strength concrete, high strength concrete, structural steel, and several major groups of common fire protection materials at elevated temperatures, which are necessary for performance-based engineering calculation, are presented. Modern fire-resistant design methodologies for concrete and steel structures are discussed, including methods based on standard fire tests as well as performance-based engineering analysis methods that involve heat transfer and structural analysis at elevated temperatures. This report is not intended to provide step-by-step design procedures. Rather, it provides general guidance on the approaches to, and practical aspects of, implementing a fire resistant design approach for concrete and steel buildings. The guidance includes key concepts and examples for identifying performance objectives, conducting risk analyses, selecting design fire scenarios and fire exposure curves, and implementing heat transfer and structural response analyses for the structural fire resistant design of concrete and steel structures.
Citation: NIST Interagency/Internal Report (NISTIR) - 7570Report Number:
NIST Pub Series: NIST Interagency/Internal Report (NISTIR)
Pub Type: NIST Pubs
building codes, concrete structures, design fire scenarios, fire resistant design, fire risk mitigation, performance-based fire engineering, steel structures, structural response analysis, thermal analysis.