Strength and fracture properties of industrially prepared steel fibre reinforced concrete

The paper reports on a study of steel fibre reinforced concrete (SFRC) which was prepared using normal industrial mixing, compaction and curing conditions. Both strength (compressive and tensile) and fracture (toughness measurements) characteristics have been investigated with test specimens prepared from 5 m long SFRC piles. The piles contained only steel fibre reinforcement and were manufactured in exactly the same way as ordinary piles. Slight differences in the tensile strengths (determined via torsion tests) were observed due to the existence of preferential fibre orientation. Flexural tests on notched beams (to evaluate fracture characteristics) produced a much more stable, reproducible, test than that observed for un-notched beams. Hence, it is concluded that the notched beam is a better geometry in terms of test stability and reliability. The results showed that tests specimens taken from industrially prepared SFRC displayed similar characteristics compared to that observed with test specimens prepared under laboratory conditions, with regards to the strength, fracture characteristics and, in particular, the variation observed. (C) 2002 Elsevier Science Ltd. All rights reserved.