NUMERICAL MODELLING OF FULL SCALE PRESTRESSED FIBER-REINFORCED CONCRETE THIN WEBBED OPEN SECTION ROOF ELEMENTS

摘要

Steel fibers have been shown to provide adequate ductility and strength in several structural applications, one above all in substituting the minimum code required shear reinforcement of beams, particularly if made of precast high performance concrete. The following research investigates the effectiveness of fibers in replacing the secondary reinforcement in thin webbed precast elements, which are nowadays mainly utilized as roof elements. Based on experiments carried out at the University of Brescia on a set of three full scale roof elements, made of self compacting fiber reinforced high performance concrete, numerical analyses were performed in order to model the fiber effect on the global structural behavior, which, in terms of greater ductility, crack control and lower transverse effects, benefited of the presence of fibrous randomly distributed reinforcement. Analyses were performed using a smeared crack damage model provided by the latest release of ABAQUS (V. 6.4). The numerical results turned out to be in close agreement with the experiments, particularly with respect to the first cracking point, the initial crack pattern, and its development. A discussion on the FE program merits is also presented.