SR34 Fire resistance of New Zealand concretes: Part 1 (1991)

The thicknesses of concrete elements required to achieve various fire resistance ratings (FRR) in New Zealand are notional and based on overseas building codes and test results. Because of variation in the properties of the constituent aggregates, a test programme was undertaken to determine the reliability of the notional ratings when applied to concretes containing locally produced aggregates.

The results showed that the current FRRs used in New Zealand are adequate for the thickness tested. Indicative information has been collected on damage to concrete after firing, and a technique for the measurement of residual compressive strength has been evaluated.

Recommendations are made for further work in the extrapolation of data to other concrete thicknesses for both walls and floors, the assessment of the influence of loading and performance of high-strength concrete and the use of techniques for assessing post-fire loadbearing capacity.