Underground Construction - July 2022 - 35

Convention Review: CIGMAT 2022
highest-density, short-term and reversible energy storage
mediums include synthetic fuels, such as hydrogen, electrochemical
solutions in the form of batteries, thermal energy
and mechanical energy (kinetic and potential energy storage).
Civil engineers have a significant role in traditional potential
energy storage in the form of pumped storage hydropower,
otherwise known as PSH. Water is pumped from a lower
to a higher natural or constructed reservoir to store energy;
when needed, it is allowed to reverse flow to recover most
of the stored energy. Civil engineering requirements include
dams, levees and underground construction.
Water & wastewater
The third session, moderated by Mackrena Ramos from
Lockwood, Andrews and Newnam, Houston, discussed water
and wastewater issues.
Cristopher Jackson, project engineer-master planning, at
San Antonio Water System (SAWS), talked about the history
of wastewater collection and treatment systems, and provided
background, key considerations and some details of the City's
Sanitary Sewer Overflow (SSO) Consent Decree (CD) process,
lessons learned, and program effectiveness.
The seventh-largest city in the nation. San Antonio has
12,500 miles of pipelines,100,000 manholes, 73 water pump
stations, 191 wells and 117storage tanks. SAWS also has153
Lift Stations and four treatment plants.
There are more than 40 cities in the U.S. addressing SSO,
as part of a CD, through comprehensive programs that require
operations, maintenance, and capital investment. SAWS
has reduced SSOs by over 60 percent since 2010. Investments
for the next five years total more than $2.3 billion and include
plans to further reduce SSO.
Veronica Villalobos-Pogue, from the Texas Water
Development Board (TWDB), discussed flood mitigation,
challenges and future plans of its innovative water technology
programs. There is also increasing interest in the recycling of
water and storing flood water in the aquifers.
Jan Conant, coatings specialist at Warren Environmental,
discussed high-build epoxy coating and its uses for protecting
and rehabilitating critical infrastructure assets.
High-build, or ultra-high-build formulations are designed
to provide structural renewal for deteriorated structures. The
product can be applied from 100 mils up to 500 mils with the
typical specified thickness between 125 mils and 250 mils. The
product exhibits tremendous adhesion to various substrates,
including concrete, brick, and steel.
Properties of these materials include structural enhancement,
zero volatile organic compounds (VOCs), superior
adhesion results, and highly resistant to H2S corrosion and
treatment chemicals. Details were covered, including product
uses, compatible substrates, application methods and available
application network, and case studies related to pipelines,
manholes and wastewater treatment facilities were discussed.
Smart cement
The technical sessions were followed by C. Vipulanandan's
presentation on " Smart Cement Integrated with Real-Time
Monitoring for Construction and Repairing of Various New
and In-service Infrastructures. "
Recently, smart cement, or highly sensing chemo-thermo-piezoresistive
cement, has been developed with a real-time
monitoring system, for construction, maintenance and repair
of cemented wells, both onshore and offshore, and all types of
civil infrastructures, such as bridges, buildings, pipelines, tunnels,
highways and oil wells.
As a bulk sensor, the smart cement has no sensors buried
in it. Smart cement is a highly sensing binder that can be used
in multiple infrastructure applications for new construction
and also integrated into in-service infrastructures for real-time
monitoring.
In new construction, the smart cement can be used as the
binder to make the cement highly sensing and then used in
the construction of onshore and offshore infrastructures. The
piezoresisitive axial strain at peak stress for the concrete with
smart cement was over 100 percent, which is 336 times higher
than the concrete failure strain of 0.3 percent.
Vipulanandan discussed the performance of smart cement
grout with water-to-cement ratio of 0.8, and the piezoresistive
failure strain was over 150 percent. To ensure safety and extend
the service life of the infrastructure, changes in the construction
and repair materials must be monitored with the varying
loadings and environments. Hence, it is also important to integrate
the real-time monitoring tools into these applications.
A new material characterization method has been developed
and was used to identify the critical electrical property of the
smart cement and the electrical resistivity was identified as the
critical property to monitor. Therefore, a two-probe method
was developed to monitor the resistivity changes in the cement.
In addition, a new approach was developed to wirelessly
transfer the two-probe monitoring of smart cement, smart
concrete and smart grout, to a phone. This method can be used
to evaluate the quality of mixing and curing of the materials,
with time and stress changes.
Another new method uses band pass filters (BPF) to monitor
the installation and performance of deep oil and gas wells
as well as deep foundations, and pipelines during construction
and in-service maintenance.
Following the
technical
sessions, posters on research
activities at CIGMAT and the Department of Civil and
Environmental Engineering were on display in the Exhibit area.
Various grouting, pipe manufacturer, material supply, pipe
condition monitoring, geotechnical engineering and wastewater
rehabilitation companies participated in the exhibition.
CIGMAT 2022 Conference Proceedings is posted on the
CIGMAT web site:
http://cigmat.cive.uh.edu. CIGMAT
2023 will be held on March 3, at the University Hilton,
University of Houston. UC
UCONonline.com | JULY 2022 35
http://cigmat.cive.uh.edu http://www.UCONonline.com
Underground Construction - July 2022

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