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Page 45
allied
academies
Journal of Materials Science and Nanotechnology | Volume 3
February 25-26, 2019 | Paris, France
Materials Science and Engineering
2
nd
International Conference on
Develop smart adaptable reinforced concrete slabs using iron based shape memory alloy
Raafat El Hacha
University of Calgary, Canada
I
n current design practice, structures are designed as
passive structures. That is, they are designed to support the
anticipated loads throughout their lifespan. This means, until
the structure experiences the anticipated load, there is excess
capacity. Smart structures are adaptive structures which have
the ability to understand their condition or surroundings and
react to changes in a beneficial manner using a sophisticated
system of sensors, controllers and actuators. Compared to
passive structures, smart structures are able to increase
their capacity only when required, creating more efficient
structures. Smart structures require a material that can change
as required and shape memory alloy (SMA) is a potential
candidate for this application. SMA has the ability to recover
relatively large strains by either heating it (known as shape
memory effect) or by releasing it after it’s been loaded (known
as pseudoelasticity). Originally discovered as a nickel-titanium
(Ni-Ti) alloy in 1962; however, the special characteristics of SMA
have recently been found in iron based alloys (Fe-SMA), which
have significantly lower manufacturing costs than Ni-Ti making
them suitable for the relatively larger structures prevalent in
civil engineering. This research proposes to develop a smart
concrete (RC) slab reinforced using SMA. The significance of
smart slabs are that engineers can design more efficient and
resilient structures. Currently, an inherent defect of RC slabs
is their tendency to crack. Although it is possible to design RC
structures that do not crack either with increased materials,
material strength or by current prestressing techniques,
this is highly impractical and results severely over designed
structures. With smart slabs, the smart force can counteract
loading throughout its lifespan and it would be possible to add
smart force on demand before the concrete cracks. Uncracked
concrete prevents moisture from contacting the internal
reinforcement and is significantly more resilient to bending.
The result could be more durable structures, less maintenance
and strengthening and reduced need for expensive prestressing
or strengthening operations potentially saving billions that
would otherwise be used to repair or maintain the structure.
e
:
relhacha@ucalgary.ca