Opportunities and risks of steel fibres in grouted joints

authored by

Ludger Lohaus, Nick Lindschulte, Steffen Anders

Abstract

Grouted Joints are typical means of connecting the supporting structure with the foundation piles of Offshore Wind Energy Converters (OWECs). The resulting gap of two steel pipes with different diameters is filled using a mineral-bound, high strength grout. Because of the special offshore conditions the grout material needs a high reliability and robustness against segregation for the pumping process. Up to now high performance concrete can be used with compressive strength exceeding 100 N/mm2. Because of the brittleness and risk of cracking in case of high performance grout material, discussions have come up in Germany whether to use steel fibres due to their crack-bridging effects. In this paper the opportunities and risks of steel fibres in Grouted Joints are described regarding to their effects on the fresh and hardenend concrete properties as well as the load-deformation behaviour of the construction. It is necessary to balance needs for the controllability of the filling process and the risk of cracking of hardened grout materials with and without fibre reinforcement. To determine the influence of steel fibres on the workability, slump flow tests with and without blocking effects were made. Currently, it is not recommended to use steel fibres for structural purposes. High doses of steel fibres, which produce an identifiable improvement of the load bearing behaviour result in critical problems for the filling process.

Organisation(s)

Institute of Building Materials Science

External Organisation(s)

Bilfinger SE

Type

Conference contribution

Pages

2422-2449

No. of pages

28

Publication date

2010

Publication status

Published

Peer reviewed

Yes

ASJC Scopus subject areas

Energy Engineering and Power Technology, Renewable Energy, Sustainability and the Environment

Sustainable Development Goals

SDG 7 - Affordable and Clean Energy