Assessment of the shear strength of steel fibre-reinforced concrete

Abstract

Steel fibres when added to concrete, form what has been termed steel fiber-reinforced concrete (SFRC). The merger of these two materials boasts an improved post-cracking strength maintaining a high durability. Such features enable the use of SFRC in structural applications thanks to the appearance in recent times of standards and recommendations that assess its structural capacity based on flexural tests. However, the shear behaviour of a structural material is of key importance and up to now there are few studies dealing with this issue. In order to widen the knowledge in this area this contribution presents the experimental results of push-off shear tests performed in SFRC. The samples employed were double-notched ones and they were subjected to compressive forces in the tip of both notches creating pure shear stresses in the ligament. The influence of the fibre dosage was analysed by manufacturing two self-compacting concretes with 26 and 70 kg/m3 of fibre. Moreover, the influence of the fibre length was studied by using 35 and 50 mm-long fibres. Furthermore, the shear behaviour was also connected with the fracture behaviour of the same specimens shown in previous studies of the same authors.