MULTISCALE PERFORMANCE OF CARBON NANOTUBES WITH BIOCAULK IN
THE SUSTAINABLE REMEDIATION OF CONCRETE FRACTURES AND FISSURES
Sathesh Kumar Annamalai$, Kantha Deivi Arunachalam*$, K.S. Sathayanarayanan#
$
Center for Environmental Nuclear Research, SRM University, Chennai -603203
#
School of Civil Engineering, SRM University, Chennai -603203
ABSTRACT
Background: Cracks and fissures are common problems in building structures, pavements and
historic monuments. Methods currently used for crack remediation often use synthetic polymers
that need to be applied repeatedly. A novel approach in crack remediation is microbiologically
enhanced crack remediation using engineered Biocaulk with Carbon nanotubes.
Objectives: Carbon nanotubes have recently achieved a significant scientific attention owing to
their extraordinary and useful properties, such as exceptional tensile strength, elastic modulus
and electrical and thermal conductivity. Bacillus sphaericus strains capable of remediation of
cubes and beams, by precipitating a dense and coherent calcium carbonate layer and
concomitantly inducing a reduction of water absorption, were characterized by a high urease
activity.
Methodology: Response surface methodology optimized media has been used for the Biocaulk
production in the biocolumn. The biocaulk produced was enhanced with the nano-particles at the
ratio of 20% of total sealant and tested for its strength.
Results: SEM analysis evidenced the direct involvement of microorganisms in CaCO3
precipitation as calcite and the presence of newly formed layer on mortar specimens surface. The
experimental results showed that the compressive strengths measured was higher at the 28th day
of the biocaulk enchanced with the nano-particles on the cracks and fissures of concrete.
Conclusion: Application of Biocaulk enhanced with nanocarbon decreased capillary water
uptake, and increased strength regaining capacity. And it is feasible to use nano-particles to
improve the mechanical properties of concrete and can be used for the remediation of cracks and
fissures of historic buildings and monuments.
Corresponding Author Email – Kanthad.arunachalam@gmail.com Phone: 09943392555 (Kantha
Deivi Arunachalam)
NATURAL RADIONUCLIDES IN DIETARY INTAKE OF PEOPLE LIVING IN
HIGH BACKGROUND RADIATION AREA (HBRA’S), TAMILNADU, INDIA.
Kantha D. Arunachalam1, B Kamesh Viswanathan2, and D. D. Rao3
Centre for Interdisciplinary Research (CIDR), Directorate of Research, SRM University,
Kattankulathur, Chennai, India1,2, Health Physics Division, BARC, Mumbai, India3.
ABSTRACT
Background: Monazite, a major constituent of thorium and other rare earth elements are present
in large quantities in high background radiation areas of South Coast of Tamilnadu. Large
amount of radionucleides get accumulated in human organs causing health problems to people
living in HBRA’s region through ingestion of food material grown in HBRA’s.
Objective: To construct a bench mark baseline of radionuclides in the diet consumed by the
human living in HBRA’s, the present study was undertaken to evaluate the radionuclide in the
food consumed.
Methods: The Market basket study and Duplicate diet study were the two methods used for the
analysis of radionuclides in food material grown in HBRA’s. The intake of radionuclides by
different age groups of male and female, through the locally grown food materials were
determined. The concentration of radionuclide’s in the food samples will be analyzed by Neutron
Activation Analysis (NAA), which is a sensitive technique to quantify the radionuclide
concentration level in parts per trillion.
Result: The GPS co-ordinates of the 10 villages recruited ranges from 0.22 – 1.75 µGy/h.
Based on the background radiation of the ten villages were classified as high, moderate and
low. Totally 183 families were surveyed and 149 families were recruited for diet sample
collection. Conclusion: Duplicate diet samples were collected from 149 families and the market
basket study was done in 5 local markets from the study area. The collected food samples were
processed for Neutron Activation Analysis and to set a baseline data in HBRA’s.
Corresponding Author Email – Kanthad.arunachalam@gmail.com Phone: 09962211166 (Kantha
Deivi Arunachalam)