Title: High Strength Lightweight Aggregate Fiber-Reinforced Concrete (HS-LWA FRC) Filled Steel Tube Columns for Increased Seismic Resistance

Author(s): J. Punchin, N. Krstulovic-Opara, and B. Brezac

Publication: Symposium Paper

Volume: 216

Issue:

Appears on pages(s): 33-48

Keywords: concrete filled tubes; ductility; energy methods; fiber-reinforced concrete; high-performance construction materials; metal fibers; stiffness

DOI: 10.14359/12890

Date: 10/1/2003

Abstract:
Damage due to recent earthquakes and the high costs of repairing old and building new structures emphasizes the need for novel ways of designing cost-effective and more seismically resistant buildings. To address this problem, the structural system considered in this paper is constructed with composite materials that display excellent earthquake-resistant properties such as high strength, high ductility and increased energy dissipation capacity. The particular composite used in this project is High StrengthLightweight Aggregate Fiber Reinforced Concrete (HS-LWA FRC). Its use in concretefilled steel tubular (CFT) columns allows for both: (a) improved seismic resistance and (b) possibly a faster and more cost-effective method of construction, than is the case with conventional buildings. The main goal of this research was to manufacture and study the seismic performance of such a composite CFT column. The ductility, stiffness degradation, energy dissipation and hysteretic response of the CFT member are reported. Testing of the CFT revealed that adequate strength was developed in the critical section, with respect to the predetermined yielding of the system. The use of fibers prevented an otherwise extremely brittle failure of HS-LWA concrete and increased its capacity for lateral expansion, leading to a ductile response of the critical column zones. As a result, large levels of ductility and energy dissipation capacity were measured during testing.