Focusing on Fibres: CTRL Experience

The Channel Tunnel Rail Link (CTRL) in the U.K. posed some demanding requirements for tunneling technology, and this article reports on the use of fiber reinforced concrete (FRC) to address some of them in Section 2 of the CTRL. The article describes select projects elsewhere that have used FRC and a history behind establishing testing procedures and standards for material properties in the U.S. and Japan. However, there remains much to be learned, especially when considered for a specific application and unique conditions such as found at the CTRL. The article describes production testing, quality control in manufacture, load tests, durability and fire protection aspects of the materials. Of 260,000 segments manufactured for the project, 0.8 percent were rejected at the factory, with 2.8 percent judged suitable for repair. The article concludes that the CTRL experience has shown FRC to be a durable and effective material.