Injektionsstoffe im Tunnelausbruchmaterial – Abfall oder Ersatzbaustoff?

Abstract

This paper examines the possibility of using excavated material with system‐related admixtures as a substitute construction material, considering the current rules and regulations in the field of landfilling or disposal. In addition to conventional injections with bentonite‐ and cement‐containing suspensions, which always require longer setting times and are relevant for classification during disposal with sulfate values in the eluate, fast‐setting multicomponent resins are suitable for filling or consolidation, e.g. fast‐reacting, high‐foaming silicate resins, polyurethane resins for stopping water ingress, or rubber‐elastic, versatile 3‐component acrylate gels. However, the discussion is currently focusing on tunnelling compounds to which foams or resins have been added and which, according to Systal's ”system‐related admixtures“, are to be remunerated as special services. This paper deals with the question how to deal with the excavated material contaminated with organic matter under soil protection law and waste law. On the basis of the results of laboratory tests, the question arises as to whether tunnel excavation with a few percent of organic, system‐related admixtures would not make an excellent substitute building material in the sense of the draft substitute building materials ordinance.