Structural performance of fiber-reinforced SCC beams containing Stalite lightweight aggregates

Abstract

This study intends to investigate the structural performance of large-scale fiber-reinforced lightweight self-consolidating concrete (LWSCC) as well as lightweight vibrated concrete (LWVC) beams made with Stalite aggregates under flexure loads. A total of fourteen reinforced concrete beam specimens were tested under a four-point bending configuration until failure. Two different binder contents (550–600 kg/m3), two types of lightweight aggregates (coarse and fine Stalite aggregates), two PVA fiber lengths (8–12 mm), and three fraction volumes of fibers (0.3%, 0.5%, and 1%) were considered in this study. The structural performance of the tested beam specimens was assessed in terms of load–deflection response, cracking behavior, energy absorption, displacement ductility, cracking moment, and ultimate flexural strength. This study also investigated the performance of design code provisions in predicting the cracking and ultimate moment capacities of all tested specimens. The results indicated that using shorter PVA fibers seemed to better improve the structural performance of LWSCC beams in terms of deformability, energy absorption, ductility, and ultimate flexural capacity than using longer PVA fibers. Using up to 1% PVA8 fibers in lightweight concrete beams made with Stalite aggregates proved to completely compensate for the drop in ultimate flexural strength that resulted from the use of low-density aggregates and further helped the beams to experience much higher rates of deformation. The results also showed that the model proposed by Henager and Doherty well predicted the ultimate moment capacity of LWSCC/LWVC beams reinforced with PVA fibers.