Description

The rational design procedure described in this document applies structure engineering principles and material properties at elevated temperature to the calculation of fire resistance of reinforced or prestressed concrete beams and floor slabs.

Current methods used in New Zealand usually rely on notional tabulated data provided in SANZ Miscellaneous Publication MP9 for reinforced or pre-stressed concrete structural elements. This tabular data specifies fire resistance according to the minimum width or thickness of the element and the amount of concrete cover provided to tensile steel.

Scope

TR8 applies to floor systems:

• which may be rectangular or tapered in cross-section (for beams), or tee-beams, with a minimum width of 100 mm;
• which are made with normal-weight concrete (assumed density greater or equal to 2000 kg per m3), light-weight concrete (assumed to be less than 2000 kg per m3),
• in which support conditions are assumed to be either simply supported or continuous over the supports;
• where the section includes either prestressing tendons or deformed reinforcing bars;
• which are designed in accordance with the requirements of NZS 3101, New Zealand Code of Practice for the Design of Concrete Structures and NZS 4203, New Zealand Standard Code of Practice for General Structural Design and Design Loadings for Buildings;