Condition assessment and repair of concrete tunnel lining after fire

Author(s): K. Mavar, E. Marušić
Paper category: Conference
Book title: Concrete Repair, Rehabilitation and Retrofitting III (ICCRRR)
Editor(s): M.G. Alexander, H.-D. Beushausen, F. Dehn, P. Moyo
Print ISBN: 978-0-415-89952-9
Publisher: Taylor & Francis Group
Pages: 305- 306
Total Pages: 2
Language: English

Principle influence of fire i.e. high temperatures in concrete are physical changes (loss of compressive strength, tensile strength, modulus of elasticity, increase of porosity, spalling and cracking) and chemical decomposition of certain components in concrete depending on temperature reached (calcium hydroxide at 400°C, limestone at 900 1000°C).
In this paper a case study of Tunnel St Elijah through mountain Biokovo will be presented. Its secondary concrete tunnel lining was exposed to high temperature when formwork caught fire. Concrete was 10–16 hours old. The first performed visual inspection revealed different coloration on area caught in a fire. It depends on distance of centre of fire, position of formwork during fire and direction of wind. By visual inspection, the positions for in-situ testing and cores drilling for laboratory testing were determined. Those included the following: determination of compression strength and density on samples from sound and discolored concrete and comparison of values, determination of adhesive strength by pull off testing on sound areas and discolored areas, difference between Schmidt hammer test results, determination of loss on ignition to establish if decomposition of C-S-H gel occurred. Test results, condition assessment and repair of secondary concrete tunnel lining will be presented.

Online publication: 2014
Publication Type: abstract_only
Public price (Euros): 0.00