Background/Motivation

Shotcrete applications remain indispensable in infrastructure construction and maintenance. Research results are available that suggest the utilization of slags from electric arc furnaces in steel production as cement replacement.

Contents and goals

ParaStruct's material technology expertise has already been utilized in several client projects with EAF slags, with the project consortium aiming for promising environmental improvements through gradual cement replacement in the area of spandrel filling in the context of WienerLinien infrastructure measures, with the "U-Bahn Neubau Nord" department acting as input provider.

Methodical Approach

Based on various EAF slags, test series on construction applicability are being conducted, consisting of material surveys, testing of various mix ratios, material characteristic determinations, and practical application with commercially available shotcrete equipment. This is structured into literature review, materials research, feasibility study, process engineering, life cycle analysis, and partner communication.

Upon successful testing, the exploration in the course of SlagShot will serve as a basis for further commercial utilization of the findings in order to significantly reduce the necessary amount of cement in a critical area. The exploration is intended to determine whether it is possible to achieve strengths up to C20/25 with EAF slags in shotcrete.

The targeted KPIs are:

• Reduction of CO2 emissions in binders for shotcrete C20/25 up to 50%
• Reduction of primary raw material requirements: 40–70%
• Shotcrete based on EAF binder 10% cheaper than standard shotcrete
• Time horizon until market launch: <3 years after follow-up project start

Expected Results

Upon successful completion, there is explicit interest in subsequent joint R&D projects, as well as enhanced collaboration in the utilization of residual material quantities and application of circular construction materials.

This strengthens and supports the urban circular economy, climate change adaptation, climate neutrality efforts, as well as the future security of the City of Vienna and simplifies adoption for all municipalities and cities in Austria and further throughout the entire EU.

Urban planning, project developers, general contractors, and planners will have access to new, economical, and valuable building materials in the medium to long term with the resulting material solutions.

One of the most important building blocks on the path to a climate-neutral city. The increased resource efficiency, reduced purchase prices, as well as lower waste costs and landfill volumes underscore the shared vision of circular construction materials and circular construction economy.

Project management

ParaStruct GmbH

Project or cooperation partners

• DI Thomas Matthias Romm ZT
• Wiener Linien GmbH & Co KG

ParaStruct
Georg Breitenberger
Speckbacherstrasse 39
A-6020 Innsbruck
Tel.: +43 (664) 310 42 21
E-mail: georg.breitenberger@parastruct.com
Web: www.parastruct.org