Upgrading the Seismic Performance of Reinforced Masonry Columns Using CFRP Wraps

Abstract

Compared with reinforced concrete, relatively fewer experimental studies address the behavior of masonry columns under com- bined axial load and cyclic flexure. There exist reinforced concrete masonry (RCM) columns that are part of the moment resisting system of masonry structures that are in need of seismic upgrade. Wrapping such susceptible RCM columns with carbon fiber-reinforced polymers (CFRP) is expected to enhance the seismic behavior of reinforced masonry columns considerably. This paper focuses on assessing the seismic performance of RCM columns wrapped with CFRP. In this experimental study, six 1.4-m reinforced masonry columns were constructed and tested when subjected to constant axial force and cyclic lateral excitations. The columns had a cross-section of 390 mm × 390 mm and were constructed using bull-nosed concrete units. The first column had no CFRP wraps and was used as a control specimen whereas the other five columns werewrapped using different layers of CFRP sheets or different wrapping schemes. From the tests, it was observed that wrapping the masonry columns with CFRP wraps enhanced the seismic performance of the columns by offering more ductile behavior, increasing both strength and energy dissipation capacity. DOI: 10.1061/(ASCE)CC.1943-5614.0000252. © 2012 American Society of Civil Engineers. CE Database subject headings: Reinforced concrete; Masonry; Columns; Fiber reinforced polymer; Seismic effects; Ductility. Author keywords: Reinforced concrete masonry (RCM) columns; CFRP wraps; Seismic; Ductile behavior.