Development of an SFRC segment within a TBM tunnel: flexural beam test for evaluation of SFRC
A Korean research project examining the development of full steel fiber reinforced concrete (SFRC) tunnel segments was launched during 2011 and is ongoing. The latest part of this project focused on member-scale evaluation of SFRC and here we present the results of laboratory tests undertaken during 2013. These tests used 16 beam specimens cast with SFRC, and the flexural performance of these beams was tested using the conditions specified in Model code 2010. These tests focused on the effects of variations in concrete strength (45 and 60 MPa), aspect ratio, and the mix ratio of steel fibers with hooked ends. The results indicate that steel fibers with lengths of 60 mm and diameters of 0.55 mm satisfied the conditions for a compressive strength of 45 MPa, although no fibers satisfied the conditions for a 60 MPa compressive strength.