Utilising excavated rock material from tunnel boring machines (TBMS) for concrete

Author(s): Torjus Berdal, Pål Drevland Jakobsen, Stefan Jacobsen
Paper category: Proceedings
Book title: SynerCrete’18: Interdisciplinary Approaches for Cement-based Materials and Structural Concrete: Synergizing Expertise and Bridging Scales of Space and Time Vol. 1 & 2
Editor(s): Miguel Azenha, Dirk Schlicke, Farid Benboudjema, Agnieszka Jędrzejewska
ISBN: 978-2-35158-202-2
e-ISBN: 978-2-35158-203-9
Publisher: RILEM Publications SARL
Publication year: 2018
Pages: 363-368
Total Pages: 6
Language : English

Abstract: There are more than 2000 completed road, railroad and hydropower tunnels in Norway, with a current annual production of more than 7 million solid cubic metres excavated rock. The road and railroad tunnels are consumers of concrete, which is utilised for rock support, water- and frost protection. A small portion of the excavated rock affiliated with Norwegian tunnelling is used as concrete aggregate, while the major part of the rock is used for landfill. This paper reviews the potential of utilising excavated rock obtained by tunnel boring machines (TBM) as concrete aggregates, including results from recent European TBM projects that have utilised the excavated rock for concrete aggregates. Finally we present test results from excavated rock material from two new (including one ongoing) Norwegian TBM projects. Particle Size Distribution (PSD) of the filler / fines fraction and effect of the fines fraction (< 0.125mm) of the rock material on flow of fresh filler modified cement paste were measured. The reuse in concrete of excavated rock from 8 different recent European TBM projects varied from zero to 100 %. Reviewed PSDs and own PSD measurements show that TBM PSDs vary within wide ranges. Content of fines < 0.1 mm content can be more than 20 % of the total TBM and even higher when the coarsest material is used as feed in production of crushed aggregate. The newest project reviewed, the Norwegian Follo line, is generating the finest material with 50 % < 4 mm indicating the importance of rock quality in addition to TBM-technology for fines generation. The flow results of filler modified paste show that the TBM fines from the two projects with size 0-0.125 microns have very similar effect on fresh cement paste flow properties as a replica limestone filler with similar PSD composed from 3 different filler fractions.

Online publication : 2018
Publication type : full_text
Public price (Euros) : 0.00