Self-Centering Concrete Structures

Recent major seismic events, including the 2011 New Zealand Earthquake and the 2010 Chile Earthquake, have demonstrated similar trends to previous earthquakes; that current state-of-the-art seismic design codes ensure, for the most part, that loss of life is avoided. It is accepted in the engineering community that significant damage can be expected for major earthquakes. However, building officials and owners are not aware that many structures will not be serviceable after a major earthquake, resulting in significant economic consequences. This has led to the development of self-centering structural methodologies that result in a structure that is serviceable after an earthquake and, furthermore, reduces permanent damage. The recent emergence of Shape Memory Alloys (SMAs) for structural engineering applications has provided new opportunities for developing novel self-centering structural systems. Superelastic SMAs are characterized by significant strength, strain, ductility and energy dissipation capacities. However, the most appealing feature is the capacity to restore to its original shape.

The objective of this research program is to investigate and develop new self-centering technologies for concrete structures by exploiting the salient features of superelastic SMAs. This program includes numerical modelling and experimental testing. The Globalink student will contribute to numerical studies and small-scale experimental tests.

Currently, a long-term experimental program is ongoing which focuses on old construction, in particular non-ductile structural components, such as poorly detailed reinforced concrete shear walls and frames. The structural components are detailed according to pre-1970s design standards, such as the American Concrete Institute Standard ACI 318-63; a representative benchmark standard for structural concrete design practice prior to the enactment of seismic design provisions. Retrofit strategies will be investigated including using SMAs as external diagonal bracing. For optimization, a system will be developed where a short SMA link will be coupled with rigid steel elements in an X-bracing retrofit. The Globalink student

Faculty Supervisor:

Dan Palermo

Student:

Marina Maciel

Partner:

Discipline:

Engineering - civil

Sector:

University:

York University

Program:

Globalink