More and more people are asking whether a building component complies with the building code. Important then is that the product can function well structurally for 50 years and will not fail. In general, reference can often be made to buildings or constructions that have existed for a very long time, such as, for example, the bridge over the Twente Canal near Almen built by the Canadians in 1945, which has been written about regularly. In Belgium, there is also a Baileys bridge from the same period in Postel.
Earlier research on conductor rail has shown that even when only 25% of the zinc layer is still intact, the strength of the steel and thus residual life is present. More and more, one will see guide rails being reused as a result. After all, there is a huge environmental gain to be made by doing so. The so-called reference period of a structure depends on the structure itself and its use. In many cases, however, 50 years will be the norm.