This presentation provides a detailed summary of the structural fire testing requirements for concrete used in tunnel infrastructures.

Contrasting with building fires, tunnel fires are more significant within a few minutes due to the confined space, which can cause concrete spalling and jeopardise the tunnel supporting capacity. This fire-induced damage should be a substantial concern to designers. The catastrophic European tunnel fire events in 1999 and 2001 led to the development of innovative regulations and recommendations, including guidelines endorsed by the European Federation of National (EFNARC 132F r3:2006) and Efectis R0695:2020. This presentation provides an overview of these test standards and the tests conducted at the Victoria University full-scale NATA facility.

Presentation overview

As more cities in Australia and overseas dig deep underground to build congestion-busting car and train tunnels, they are exposed to risks incurred by fire-induced damage to tunnel lining. Spalling occurs when small pieces of concrete explode during fire or mechanical pressure, weakening the concrete and putting tunnels at risk of collapse. It has been linked to tunnel disasters and deaths overseas, including the Mount Blanc and St Gottard Tunnels in Switzerland (1999 and 2002 respectively).

Dr Maurice Guerrieri is using his expertise in ‘concrete spalling’ to test how various concrete samples respond to fire. Using the fire testing facilities in Victoria University, he is working on major tunnel projects to ensure they meet relevant fire-testing standards.

The presentation will demonstrate the test results on several concrete samples with various ratios of aggregate rock, sand, gravel and cement in temperatures of up to 1300 degrees centigrade to test for spalling since late last year. It offers useful lessons to tunnel designers, contractors, project managers, asset owners, and so forth.

Speaker bio

Professor Maurice Guerrieri is a senior Principal research fellow within the Institute of Sustainable Industries & Liveable Cities (ISILC) at Victoria University. He is the chief engineer in charge of the NATA Structural Fire Testing Facility located at the Werribee Campus. Maurice’s research interest is centred around the performance of concrete in fire and, to date, has undertaken full-scale structural fire testing relating to tunnels for some of Australia’s major infrastructure projects.