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Author
Inwood, M.
Title
Review of the New Zealand Standard for Concrete Structures (NZS 3101) for High Strength and Lightweight Concrete Exposed to Fire.
Coporate
University of Canterbury, Christchurch, New Zealand
Report
Fire Engineering Research Report 99/10, March 1999, 78 p.
Keywords
structures | concretes | lightweight concrete | standards | thermal properties | elastic properties | literature reviews | spalling | insulation
Identifiers
review of standards for design of fire resistance; concrete strength at elevated temperatures
Abstract
This report describes the thermal properties, strength, and elastic modulus of lightweight, normal, and high strength concrete at elevated temperatures. Section 6 (Design for Fire Resistance) of the New Zealand standard for concrete structure (NZS 3101, 1995) provides recommended values and minimum requirements for concrete at elevated temperatures. These values will be reviewed with respect to overseas standards and experimental data to find their applicability to lightweight and high strength concretes. A series of tests were performed on lm x lm lightweight and high strength concrete specimens to determine their insulation fire resistance. The specimens were produced in three thicknesses; 60, 130, and 175mm. This follows the method of earlier tests by Wade et al. (1991) and Wade (1992) on New Zealand aggregate concretes. It was determined that the strength reduction curve given by NZS 3101 over-predicts the strength of high strength concrete at elevated temperatures, though the values for elastic modulus and insulation fire resistance can be applied to high strength concrete. The insulation fire resistance, strength, and elastic modulus values given by NZS 3101 were found to also apply to lightweight concrete. The report recommends a change to the elastic modulus curve given in NZS 3101. The purpose of this is to give consistency between the strength and elastic modulus curves, which do not currently reach zero at the same temperature.