May 2021 Vol. 76 No.5
Rehab Technology
Rehab Technology: CIGMAT 2021 Virtually Focuses on Infrastructure, Energy, Geotechnical, Flooding, Sustainability
The 26th one-day conference and exhibition organized by the Center for Innovative Grouting Materials and Technology (CIGMAT) and the Department of Civil and Environmental Engineering, University of Houston, “Infrastructure, Energy, Geotechnical, Flooding and Sustainable Issues Related to Houston and Other Major Cities” was held online on March 5.
More than 260 attendees participated, representing owners, consulting engineers, material supplies, contractors and academia. Nine speakers addressed a variety of topics related to three sessions, each of which ended with 10 to 15 minutes of questions and answers.
Water, wastewater, corrosion Issues
The session on water, wastewater and corrosion issues related to maintaining and monitoring, was moderated by Daniel Wong from Tolunay-Wong Engineers, Houston.
Chris Manson, project engineer with San Antonio Water System (SAWS), talked about the background and history of the SAWS Wastewater Collection and Treatment systems, and sanitary sewer overflow reduction program (SSORP) that is part of a Consent Decree requiring operations, maintenance and capital investment.
There are more than 40 cities in the U.S. addressing SSO as part of a Consent Decree. SAWS has reduced SSOs by over 60 percent since 2010. The Capital Improvement Projects for the next five years is over $2.3 billion.
San Antonio, the seventh-largest city in the nation, has 12,500 miles of pipelines,100,000 manholes, 73 water pump stations, 191 wells, 117storage tanks, 153 lift stations and four treatment plants.
Erika Mancha, manager of Innovative Water Technology at the Texas Water Development Board (TWDB), addressed initiatives and trends, including increasing interest in recycling water and in recharging aquifers with flood water and monitoring their quality and conditions in several parts of Texas.
This was followed by C. Vipulanandan’s presentation on “New Nondestructive Method to Rapidly Detect and Quantify Surface and Bulk Corrosion in Steel with Real-Time Monitoring using Vipulanandan Impedance Corrosion Model.”
Major concerns related to the maintenance of bridges, buildings, rail tracks, oil and gas wells, chemical plants, power plants, pipelines and mobile facilities are due to corrosion caused by the service conditions and exposed environments, aging of the facilities, types of usage and composition of the materials. To improve maintenance operations and also extend the service life of these structures and supporting infrastructures, it is very important to detect and quantify corrosion real-time.
In addition to daily encounters with degradation of materials due to bio-chemical reactions, stress fatigue and temperature cycles, corrosion causes oil and gas well failures, fire hazards from pipeline leakages, plant shutdowns, waste of valuable resources, loss and contamination of product, reduction in productivity and expensive maintenance. Corrosion of metals alone cost the U.S. economy billions of dollars per year and approximately one-third of this cost could be saved by proper corrosion detection and quantification.
In this study, carbon steel corrosion was evaluated in saltwater solutions using the newly developed non-destructive electrical method, which can be easily adopted in the field for real-time monitoring. Results were compared to some standard test methods, such as weight loss, corrosion rate and potential difference.
The average weight loss in 10-percent salt solution (accelerated corrosion and also representing the hydraulic fracking fluids) in one year was 1.05 percent and corrosion rate was 1.54 mm/year, using the ASTM G1 method.
Vipulanandan correlation model was used to represent the weight loss versus time relationship. The potential difference between the corroding steel and standard calomel electrode in 1M salt solution reduced from -0.680 V to -0.791 V in two years – a 15-percent total change. The new nondestructive electrical method was used to detect and quantify the surface and bulk corrosion in the field. Tests were performed to first verify the best electrical property that will be highly sensitive and represent the steel corrosion.
Findings from this study indicated changes in the newly developed electrical corrosion index for the surface (2D representation) and the resistivity (second order tensor, 3D representation) for the bulk material using the Vipulanandan Impedance Corrosion Model. Corrosion development in 750 mm (30 inches) long steel specimens were studied in the 3.5-percent salt solution (simulating sea water) for 500 days.
The changes in the specimens were monitored at regular intervals using the new, two probe method and measuring the impedance-frequency relationship using alternative current up to a frequency of 300 kHz. The surface corrosion was quantified using the new electrical corrosion index parameter, which changed over 200 percent from point to point on the surface of the corroding steel.
The change in the bulk resistivity along the length of the steel specimen was over 40,000 times (4,000,000 percent) in 3.5-percent salt solution compared to the weight loss and reduction in the potential difference. Hence, the electrical resistivity for the bulk material and the new corrosion index for the surface corrosion are highly sensing parameters for detecting and quantify the corrosion in the steel.
General session
The general session focused on expanding highway transportation infrastructures, innovative solutions for the city of Houston’s Public Works, and the current financial condition in Texas.
Initial welcome remarks by Professor C. Vipulanandan, director of CIGMAT and the Texas Hurricane Center for Innovative Technology (THC-IT), discussed the need for such a conference highlighting the experiences in major cities with rapid growth in population, new technologies and economic activities, and impact of the COVID-19 pandemic on changing conditions and regulations.
Houston is the energy capital of the United States with the largest medical center in the world. There is an ever increasing need for expanding infrastructures, meeting the energy demand and integrating the advances in technologies to meet the population growth and industrial expansion with the impact of natural disasters like hurricanes and flooding.
Eliza Paul, district engineer for the Texas Department of Transportation (TxDOT)-Houston District, discussed some of the major projects to be completed this year and several ongoing and new highway projects, valued at over $6 billion dollars, in the greater Houston area that will start in the next four years.
The TxDOT-Houston district plans, designs, builds, operates and maintains the state transportation system in six counties: Brazoria, Fort Bend, Galveston, Harris, Montgomery and Waller covering an area of 5,856 square miles. There are currently 13 major ongoing projects for the TxDOT-Houston district.
Flooding, transportation issues
Moderated by Rafael Ortega, from Aurora Technical Services, Houston, the second session was related to “Flooding and Transportation Issues,” with three presentations followed by discussions.
Atul Hannan, director of planning at Harris County Flood Control District, discussed how
HCFCD and the Federal Emergency Management Agency (FEMA) are partnering to deliver the Harris County Modeling, Assessment and Awareness Project (MAAPnext). Representing a transformative step in the definition, management, and regulation of Harris County’s floodplains, this project further contributes to the county’s resilience.
MAAPnext will provide a better understanding of flood risk throughout Harris County. This effort will yield modernized flood risk products, the majority of which aim to quantify the riverine flood risk posed by channels spilling out of banks and impacting people and structures located in the affected areas.
John Tyler, deputy director of Harris County Toll Road Authority (HCTRA), established in 1988, discussed ongoing projects and plans.
Proceedings, papers
“Trends and Economic Impacts Due to COVID-19 Virus and Cyber Attacks” compared the confirmed cases and deaths in one year around the world with the United States, and those in New York compared to Texas.
Based on one year of data analyses, January 2021 was the worst month, in terms of deaths, around the world and in the United States and Texas. It is also important that quantifying the deaths, affected and recovered humans due to the COVID-19 virus, and modeling of the trends based on the location might help to better understand the critical parameters influencing the COVID-19 impacts.
With cyber-attacks increasing by six times over the past 12 months, available resources are limited by the COVID-19 disaster. Also, changes in the rules and regulations have to be taken into account for planning current and near-future projects, and educational activities, at all levels.
“Critical Issues Related to Recycling of Waste Waters for Multiple Applications” focused on the critical need to optimize the use of over 2 trillion gallons/day (10 billion tons/day) with the rapid growth in population and industrial activities. Sources of water for potential reuse include municipal wastewater, industry process and cooling water, stormwater, agriculture runoff and return flows, and produced water from natural resource extraction activities.
These sources of water are adequately treated to meet “fit-for-purpose specifications” for a particular next use. “Fit-for-purpose specifications” are the treatment requirements to bring water from a particular source to the quality needed, to ensure public health, environmental protection, or specific user needs.
Hence, it is important to develop new technologies to treat and recycle the wastewaters in a safe and economical way and for real-time monitoring that includes the water quality at all levels of supplies, treatment and recycling operations.
Exhibits
Brief presentations from exhibitors included Hobas Pipe’s discussing the different shapes of pipes that are being currently marketed. Avanti International talked about different polymer grouts and ultrafine cement grouts.
This was followed by nine research poster presentations. Four research posters were on characterizing the smart cement behavior in direct tension, high-temperature and high-pressure curing, and monitoring potential under impact loading.
Two posters covered polymer treatment of expansive clays and one poster showed quantifying the resistivity change with moisture content in sand.
Other posters were on corrosion study of steel in cement, and characterizing the water contaminated with clay suspensions and salt representing flood waters.
A CIGMAT 2021 Proceedings was published and posted on the CIGMAT web site (http://cigmat.cive.uh.edu). The next annual conference will be held on March 4, 2022 – in person, again – at the University Hilton, University of Houston.
Comments