Fire can pose a serious threat to people, buildings and safety-critical structures, often with little warning. It is therefore essential to specify suitable and approved fastening systems from the outset, with proven performance in the event of fire.
Many European Technical Assessments (ETAs) include, in addition to load-bearing capacities under normal conditions, an assessment of the fastening’s performance in the event of fire. The corresponding performance values are either calculated on a conservative basis or determined through fire testing. These tests are based on the standard temperature-time curve (STC), as defined in ISO 834. It describes the thermal exposure assumed for fires in general building construction.
However, fires in tunnels are subject to different conditions. Accidents involving tankers carrying hydrocarbons can result in extreme fire loads. The result can be an extremely rapid rise in temperature, reaching significantly higher temperatures than those typically considered for building fires. Consequently, the thermal exposure of fastenings that must be assumed in tunnels is considerably greater than that of a fire in building construction.
To address these specific requirements, planers and engineers can refer to dedicated assessments documenting fire resistance values for tunnel fires, as determined by independent testing institutes. MKT has corresponding reports for various products that are typically used in tunnel construction: the bolt anchors BZ3, BZ3 dynamic and BZ plus, the nail anchor N, as well as the injection systems VMZ and VMZ dynamic.
This provides reliable performance data for fastenings in the event of fire across a range of applications – both for general building construction and for the specific requirements of tunnel construction.
18.08.2026
