Overview
ISO/TR 15655:2020 - Fire resistance - Tests for thermo-physical and mechanical properties of structural materials at elevated temperatures for fire engineering design - provides guidance on test methods used to characterize how construction materials behave thermally and mechanically when exposed to fire. The technical report identifies existing test methods and advises on tests that need development for use in fire safety engineering calculations. It is applicable to materials used in load-bearing construction where structural and thermal calculations are required for standard fire tests or real/design fire scenarios.
Key Topics
This technical report covers both thermo-physical and mechanical properties of common structural materials at elevated temperatures, including:
- Thermo-physical properties: specific heat, thermal conductivity, thermal diffusivity, thermal strain (expansion/contraction), emissivity, density, moisture content.
- Material-specific phenomena: charring rate (wood), spalling and moisture-driven effects (concrete and masonry).
- Mechanical properties at temperature: elastic modulus, creep, stress–strain behavior (steady and transient), stress relaxation, ultimate strengths in tension/compression/shear.
- Joints and connections: behavior of bolts and welds under steady and transient heating (shear, slip, tension, stress–strain).
- Materials covered: metals (steel), concrete, masonry, wood, plastics, fibre-reinforced materials, adhesives and other organic/inorganic construction materials.
- Guidance focus: identification of existing test standards, gaps where new methods should be developed, and relevance for fire engineering calculations.
Applications
ISO/TR 15655:2020 is intended to support practical fire engineering and design by informing:
- Fire safety engineers performing thermal and structural analysis of building elements under fire loading.
- Structural engineers assessing residual capacity and deformation of load-bearing members at elevated temperatures.
- Test laboratories and researchers developing or validating high-temperature test methods and material models.
- Manufacturers and material suppliers providing high-temperature property data for product datasheets and engineering calculations.
- Code committees and consultants integrating material behavior into performance-based fire design and risk assessments.
Who should use this standard
- Fire safety and structural engineers
- Materials scientists and researchers
- Accredited testing laboratories
- Building designers engaging in performance-based fire design
- Manufacturers of construction materials and fire protection systems
Related standards
ISO/TR 15655:2020 complements standards for fire resistance testing and material characterization (refer to normative references in the report). It is best used alongside specific test standards for fire resistance, material testing, and performance-based fire engineering guidance.