THE USE OF AGGREGATES FROM THE TRANSFORMATION OF TUNNEL EXCAVATION MATERIALS FOR THE MANUFACTURE OF CONCRETE

Abstract

The environmental regulation is changing and pushing forresource efficiency and landfill impact reduction. With this aim,tunnel construction actors must manage their projects in order touse and process the excavation material to produce concreteaggregates, if technically possible.The tender documents must take into account this obligation,including some adjustments regarding the standards, especiallyEN 206 which will allow “the engineering concrete” within theFrench edition.This communication is dedicated to this topic: aggregates fromexcavation material and the related concrete productionregarding both technical and standardization aspects. It willpresent:• Excavation material classification, ranking and selectionmethods• Processing methods according to the different way of boring• Aggregates processing methods, especially for the sandproduction• Special care to be taken for processing and use of some difficultminerals• Concrete mix design procedure for different types of concrete,shotcrete, lining concrete, back filling concrete, slabconcrete,...• Durability and hidden fault• Standardization aspects• Economical aspects.Some huge projects like the LOETSCHBERG and theGOTTHARD tunnels, the NANT DE DRANCE HPP project, willbe highlighted In order to provide some application cases.