ABSTRACT
The mix design that is used for the purpose of this research project is a modified version of the selfcompacting high performance fiber-reinforced concrete mix that was developed by Liao et al. (2006). Table 1 summarizes the water-to-binder ratio and binder proportions, which is also described in detail in Lignos et al. (2011). The HPFRC mix develops tensile properties mainly because it contains high strength hooked steel fibers, which are
1 INTRODUCTION
Recent breakthroughs in fiber reinforced concrete technology have demonstrated that engineering cementitious materials can be utilized for seismic applications including seismic retrofit. This is important for steel buildings that have been designed with old seismic provisions and might be seismically deficient due to premature fracture of beam-to-column connections at the “divot” zone (see FEMA 351). Kesner & Billington (2005) demonstrated that one way to retrofit steel moment resisting frames (MRFs) is with High Performance Fiber-Reinforced Cementitious (HPFRC) composites. Structural components that are fabricated with this material are able to dissipate energy through multiple cracking during an earthquake. The primary objective of this paper is to demonstrate the potential of the proposed HPFRC system for seismic rehabilitation of steel MRFs. For this reason two large-scale hybrid simulation tests of a steel MRF retrofitted with HPFRC infill panels were conducted at the Network for Earthquake Engineering Simulation (NEES) facility at University of California, Berkeley. Numerical modeling capabilities of the proposed retrofit system are also validated and presented.
