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Materials Science and Nanotechnology | Volume: 03
WORLD CONGRESS ON SMART MATERIALS AND STRUCTURES
&
3
rd
International Conference on
POLYMER CHEMISTRY AND MATERIALS ENGINEERING
November 21-22, 2019 | Singapore
Joint event on
H
ydration process of concrete begins when concrete
is mixed with water. Development of the early age
properties of concrete are important in determining
the load carrying capacity of concrete structures during
construction and service. Early age monitoring of concrete
is difficult due to the presence of moisture and the highly
alkaline environment inside concrete. In-situ monitoring
large volume of concrete in structures requires a large
number of robust sensors. In this study, an embedded
PZT sensor, which can be placed inside concrete and has
protection fromalkaline andmoist environment of concrete
is developed. An array of PZT sensors are placed inside a
concrete structure at the time of casting for monitoring
changes in the material over a 28-day period. The PZT
sensors are used in localized and distributed sensingmodes.
The localized sensing is based on monitoring the changes in
the electrical impedance (EI) of an embedded PZT sensor.
Changes in EI measurements are shown to sensitively
reflect the changes in hydrating concrete as it transforms
from a fluid to a solid state and during the strength gain
of the solid material. In the distributed measurement, PZT
sensors are used as actuator-receiver (AR) pairs for global
monitoring of concrete. The changes in the stress-waves
propagating through the concrete produced by changes
in the material medium are monitored. The changes in
the hydrating concrete along the stress wave travelling
path are sensitively reflected in AR measurements. The
EI and the AR measurements techniques are combined to
develop an effective methodology for monitoring the early
age changes in large volumes of concrete with less number
of PZT sensors. The EI measurements are used to assess
the changes in vicinity of sensor and the AR measurements
are used to assess the changes in bulk of concrete.
Biography
Kolluru V L Subramaniam is currently a Professor in the Department of
Civil Engineering at Indian Institute of Technology Hyderabad (IITH). Prior
to joining IITH, he was the Catell Fellow and Professor of Civil Engineering
at the Grove School of Engineering, City College of New York. He received
the James Instrument Award from the American Concrete Institute (ACI) in
1999 for his research on nondestructive evaluation of concrete. He is the
recipient of the Early CAREER award from the National Science Foundation
of U.S.A. for research on nondestructive evaluation of microstructure
development in hydrating cement. He was the Chairman, committee 215
on Fatigue of Concrete of the ACI. In 2009, he was elected as a Fellow of
the American Concrete Institute. He is an Associate Editor of the Journal of
Materials in Civil Engineering (ASCE).
e:
kvls@iith.ac.inKolluru V L Subramaniam
Indian Institute of Technology Hyderabad, India
Embedded-smart PZT sensors for combined local and distributed
monitoring of concrete structures
Mater Sci Nanotechnol, Volume: 03