The ITA working group on Shotcrete Use was formed at the ITA meeting in Toronto in 1989 and its first task was to implement a status report on the shotcreting technology in different countries. Two years later, the report ”Shotcrete in Tunnelling. Status Report 1991” was published. The primary aim with this report was to demonstrate in brief the general status of the technology in some fifteen countries, including references to current development, existing guidelines or recommendations, actively working national groups etc. Short bibliographies and abstracts of major papers were also included.
As a result of this work, it became evident that guidelines of varying status were used in some of the participating countries. During concurrent discussions within the working group a strong interest was expressed to go a step further and make a special compilation of such guidelines and recommendations.
The Swedish national group of IT A, the Swedish Rock Engineering Research Foundation-BeFo, took on the responsibility for this work and the task was entrusted to Bo Malmberg, M.Sc., of J&W who has many years of experience in the field of shotcreting technology, in particular, as regards the composition of shotcrete mixtures including additives and fibres.
This report is not to be regarded as a scientific evaluation of what has been stated in different countries but merely as a summary of the most important parts of some selected references. It does not give any detailed background to cited recommendations and just a few personal comments. It should be noted also, that some of the references used are in a draft stage, e.g. the Norwegian guidelines and EFNARC’s specifications, whereas some are officially established regulations. The idea is that this compilation should be of benefit as a reference material for those who are to make specifications for shotcrete support and also to inspire national committees who are preparing or updating any recommendations of their own. Furthermore, today’s ongoing European integration includes normative work e g in the construction sector, involving also concrete technology. So far, no technical committee on shotcrete has been established within the CEN organization. It is, therefore, of vital importance that the tunnelling community look after and participate in any planned work in this respect.
It is the hope of the IT A working group that this report will serve as a basis for further enhancement of the shotcreting technology and the exchange of information in this field within the international tunnelling community.
Stockholm, December 1992
Tomas Franzén
Animateur, WG Shotcrete Use
