Designers and producers are, according to Officine Maccaferri, showing a growing interest in steel fibre reinforced concrete for transport infrastructure “since the addition of fibres enhances toughness allowing partial or even total substitution of conventional reinforcement in tunnel linings”.
Research by Officine Maccaferri reveals the results of a numerical study of precast tunnel segments for Line 9 of the Barcelona Metro. It concludes that eccentric placement of the thrust jack is one of the reasons for longitudinal cracks present in linings.
Researchers from Delft University of Technology in the Netherlands and the University of Brescia say: “The presence of eccentricities is one of the possible unfavourable conditions that cause higher stresses in the lining. It has been demonstrated that the ultimate load reduces significantly and larger cracks are present in such loading situations.
“The load bearing capacity of a segment under jack load increases with the fibre content up to a maximum value (45 kg/cu m in the considered case) that depends on the collapse mechanism. The occurring crack widths gain benefit from the presence of fibres and continuously reduce with increasing fibre content.”
Officine Maccaferri says these results underline the importance of fibres in concrete or reinforced concrete structures.
Officine Maccaferri
Tel: +39 051 6436000
Email: comes.officine@maccaferri.com
Web: www.maccaferri.com
