Developments in fire protection design for concrete tunnels in the Netherlands

Over the last twenty years, several fires in European tunnels havecaused substantial damage to tunnel structures, involving large costsand in some cases long shutdowns of tunnels for repair works. Inthe Netherlands, concrete tunnel structures are equipped with fireprotective claddings since the early 1980’s.Efectis Nederland has been active in the development of fire testingprocedures, such as the RWS/Efectis procedure[1], since 1979 andhas performed numerous fire tests on concrete structures for tunnelsworldwide. Since the late 1990’s major improvements were made toinclude spalling of concrete in the testing procedure. In recent years,in situ fire tests on actual tunnel structures using the Mobifire mobilefurnace[4,5] has opened new possibilities, because such test can serveto determine the fire performance of old, existing tunnels, which hasbecome an important topic due to the refurbishing of existing tunnelsfollowing European legislation.The paper discusses the main technical aspects of performing spallingtests on concrete tunnel structures, both in laboratory tests as well asin on site tests.