Failure modes and shear design of prestressed hollow core slabs made of fiber-reinforced concrete

Hollow core slabs (HCS) are usually precast by extrusion and it is not easy to place stirrups; thus, it is difficult to guarantee shear resistance in some cases. This paper describes an experience using fiber-reinforced concrete (FRC) to produce HCS by extrusion to gain shear reinforcement. An experimental program consisting of 26 HCS was developed. Elements were produced and tested in shear according to the following variables: amount of steel fibers (0, 50 and 70 kg/m3) and a shear span/depth (a/d) ratio of 2.3-4.4 and 8.6. Different failure modes took place. Some of the main conclusions drawn were that fibers improve quality of the material for shear, HCS with fibers achieved greater loads than HCS without fiber reinforcement and with a more ductile behavior. © 2012 Elsevier Ltd. All rights reserved