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February 25-26, 2019 | Paris, France
Materials Science and Engineering
2 nd International Conference on
Journal of Materials Science and Nanotechnology | Volume 3
ShapeMemoryAlloy (SMA) has beenattracting the researchers
from different fields due to their superior properties. SMA is
categorized as smart material with unique class of alloy for its
ability to undergo large deformation as well as energy dissipation
capacitieswhilemaintainingasuperelasticresponseandreturning
to its original shape through stress removal (Super Elasticity) used
for new construction or through heating (Shape Memory Effect
“SME”) used for strengthening applications. This presentation
focuses on the use of SMA with the SME characteristics. The
SME represents the ability of the SMA to recover its original
shape after being deformed beyond the elastic limits through
heating. The strain recovered in this transformation process can
be utilized for prestressing applications. Therefore, by having
the pre-strained SMA reinforcement (bars or strips) attached
to the Reinforced Concrete (RC) members and then applying
heat above the activation temperature the SMA will recover the
inelastic strain and thus a presressing force will be developed
in the RC member. In other words, the pre-strained SMA itself
can be used as the supplementing prestressed reinforcement
in flexural strengthening of RC beams/slabs by eliminating the
use of specialized equipment such as hydraulic jacks. Another
strengthening application is confining RC columns using SMA
wires. This confinement technique relies on the recovery stress
generated as the SMA wire transforms to its recovery (un-
deformed) state. The confinement methodology simply involves
wrapping a pre-strained SMA wire along the perimeter of the
column. Then, heating the wire using an electrical current above
a predefined transformation temperature would trigger the
SME of the SMA that allows the wire to return to its original
state while a reactive force is created by the wires producing an
active confinement pressure. Findings from many researchers
added a valuable knowledge to the field of strengthening RC
structures and widened the potential applications of the SMA in
the structural engineering field.
Speaker Biography
Raafat El-Hacha is a Professor of Structural Engineering at the University of Calgary in the
Department of Civil Engineering. His pioneer research has been recognized as pushing the
boundaryofknowledge inusing innovativeandsmartadvancedmaterialsforstrengthening
existing structures and for new construction, such as fibre reinforced polymers (FRP),
shape memory alloy, and ultra-high performance concrete for hybrid structural systems
in bridge applications and other structures. He published over 220 journal and conference
papers, co-authored 3 refereed design guidelines. Supervised and graduated 42 PhD and
MSc students. Served as guest editor for 3 journals and edited/co-edited 8 conference
proceedings. He is a Fellow of the International Institute for FRP in Construction (IIFC) and
the Canadian Society of Civil Engineers (CSCE). He is the recipient of several awards and
fellowships including the CSCE Casimir Gzowski Gold Medal, CSCE Excellence in Innovation
in Civil Engineering Award, IIFC President’s Award, Killam Professorship Award, Erasmus
Mundus International Fellowship (twice) and many others for his outstanding academic
and professional achievements.
e:
Raafat El-Hacha
University of Calgary, Canada
Strengthening concrete structures using shape memory alloy