May 2024 Vol. 79 No. 5
Features
CIGMAT holds 29th annual conference
Organized by the University of Houston’s Center for Innovative Grouting Materials and Technology (CIGMAT), and Department of Civil and Environmental Engineering, "Infrastructure, Energy, Geotechnical, Flooding and Sustainable Issues Related to Houston and Other Major Cities" was held March 1, at the University of Houston-University Hilton.
More than 300 participants and 14 invited speakers attended the 29th annual conference and exhibition, representing owners, consulting engineers, material suppliers, contractors and academia.
Professor C. Vipulanandan, director of CIGMAT and the Texas Hurricane Center for Innovative Technology (THC-IT) delivered the welcome remarks on the need for such a conference to highlight the experiences in major cities from rapid growth in the population, development and application of new technologies and economic activities, with changing conditions and regulations.
Houston is the likely location because it’s the energy capital of the United States and has the largest medical center in the world with ever-increasing need for expanding the infrastructures, meeting the energy demand and integrating the advances in technologies to meet the population growth and industrial expansion, plus the impact of natural disasters like hurricanes, tornadoes, extreme temperatures and flooding.
General session
The general session focused on expanding highway transportation infrastructures and controlling traffic congestion, innovative solutions for public works, and offshore energy production around the world over the next few decades.
Michael Ereti, director of Capital Projects, city of Houston Public Works, discussed recent updates on the construction management programs, debris management and challenges after flooding; and new plans for continuing various Houston operations with the growing population.
Brenda Bustillos, project manager of ConnectSmart Applications at the Texas Department of Transportation-Houston District, discussed some of the major challenges on highways related to traffic congestion and integrating the many variables into the ConnectSmart phone application to minimize the losses. She also discussed many safety issues during driving and accidents.
Brent Seifert, engineering manager, Shell International-Exploration and Production, talked about the delivery of oil and gas from offshore using alternative energy, including wind. He also covered the importance and challenges in construction and maintenance of deep subsea pipeline infrastructures for the transport of oil, gas, and other products across vast distances beneath the ocean. These pipelines are critical components of the global energy supply chain, enabling safe and efficient movement of resources from offshore production facilities to onshore processing facilities or distribution points.
Technical sessions
Four technical sessions were held on various topics to highlight the growth, challenges and changes happening in and around major cities.
The first panel discussion, on "Flooding, Construction and Maintenance Issues,” was moderated by Rafael Ortega, of Aurora Technical Services, Houston.
Jonathan Holley, from Environmental Services-Harris County Flood Control, discussed “Nature-Based Solutions to Flood Control in Harris County.” This included planning, designing, implementing and maintaining an extensive system of drainage and flood control infrastructure, encompassing 2,500 miles of channels and over 200 stormwater detention basins. Given the area’s terrain, climate and storm patterns, it’s important that improvements to the flood control system are designed and maintained to work, while having appropriate regard for community and natural values.
Nature-based solutions leverage the nature and power of healthy ecosystems to optimize infrastructure. Floodplain preservation, natural stable channel design, wet bottom detention basins with stormwater quality treatment wetlands, native tree planting, and avoidance and preservation of sensitive habitats are a few of these solutions used by the Flood Control District. Harris County provides more than just drainage, but also creates valuable greenspace, wildlife habitat, and improved water quality.
Kathlie Jeng-Bulloch, director of the Engineering Department, at the city of Huntsville, discussed “CIP Programs and Lessons Learned” in the rapidly growing city.
Huntsville has approximately 47,000 citizens, including the Texas Department of Criminal Justice (TDCJ) and Sam Houston State University (SHSU). The water system consists of approximately 290 miles of water lines ranging from 0.75-inch to 30-inch diameter.
The five-year CIP Program includes $204 million in water, wastewater, streets, drainage, sidewalks, aviation and general project categories. It consists of $54 million of city funds, and $61 million of revenue bonds. Remaining funding will be the subject of future bond issues and/or grant applications. It includes 33 water projects, 49 wastewater projects and 11 drainage projects.
The proposed five-year TRA CIP Program is approximately $131 million, including raw water intake, raw water transmission improvements, treatment plant updates, and treated safe drinking water high-service transmission improvements.
Nina Joshi, supervising engineer of Transportation and Drainage Operations, city of Houston, discussed “Resilient Houston: Rehabilitation Projects and Green Stormwater Infrastructure.”
Rehabilitation projects are planned improvements to extend the life and effectiveness of existing infrastructure delivered, as a whole, versus providing solutions to isolated challenges. Projects may incorporate Green Stormwater Infrastructure, when feasible and beneficial.
Local Drainage Program (LDP) is one of the two major drainage rehabilitation programs within the Stormwater Operations Branch of Houston Public Works (HPW). LDP leads the design and construction of comprehensive rehabilitation projects that include upgrades to transportation and drainage infrastructure. The program was established to address drainage infrastructure maintenance and rehabilitation that exceeds internal maintenance capabilities. LDP is tasked with providing upgrades to existing drainage systems to provide acceptable levels of service during normal rain events.
Locations are primarily nominated by maintenance sections when the scope of work exceeds maintenance capabilities and/or high-level maintenance/rehabilitation is required. LDP scope may include upgrades to enclosed and open drainage systems, curb and gutter adjustments to reduce/eliminate ponding, pavement resurfacing, overlays, installation and/or repair of sidewalks and other pedestrian and bicycle facilities.
Additional presentations
The second, parallel session, “Infrastructures and Transportation Projects,” was moderated by Daniel Wong from Tolunay-Wong Engineers, Houston.
Andy Meyers, commissioner of Fort Bend County, Sugar Land, Texas, discussed the county’s “Critical Infrastructure: Energy, Industry, Mobility, and Safety.” Fort Bend County is one of the most diverse and fastest-growing counties in Texas and the U.S.
Also, topics related to population growth, residential and commercial development, and priorities for budget allocations were discussed, as well as critical infrastructures related to mobility, water and sewer pipelines, drainage and flood mitigation, and energy. In addition, Myers discussed the benefits and challenges in developing nuclear energy.
The third session, on “Water and Wastewater Issues,” was moderated by Mackrena Ramos from Lockwood, Andrews and Newnam Inc., Houston.
The first speaker was Jeff Haby, vice president of Production and Treatment, San Antonio Water System (SAWS), one of the largest water utilities in the United States, serving over 2.1 million people with almost 8,000 miles of water main.
He highlighted that what has always made San Antonio special is the abundance of water from the Edward’s Aquifer. It has made robust life possible in a semi-arid region. It has also made San Antonio water concentric and, therefore, has made the city’s path to water resiliency ever changing.
The first thing SAWS did was implement an internationally renowned conservation program, followed by the largest direct-use recycling system in the U.S. In 2004, the city started up the Aquifer Storage and Recover Facility, which allows SAWS to store water, when rainfall is abundant, for times of drought.
Over the next 20 years, SAWS continued to diversify its Water Resource portfolio. Today, it has 14 water supply projects from eight different sources.
Of course, at a water utility, the challenges are never done. The San Antonio-to-Austin mega region is one of the fastest-growing areas in the United States, with a current population of five million expected to grow to six million by 2030.
In February 2021, SAWS, along with the rest of Texas, faced the challenges of Winter Storm Uri. As a result of its impacts on the Texas Power grid and water utilities, the State Legislature passed Senate Bill 3, which requires water utilities to maintain water pressure during extended power outages. SAWS, in partnership with CPS Energy, the electrical power provider for San Antonio, will be placing generators at many of its facilities to ensure water service is provided during loss of power.
SAWS continues to plan for new water supplies, considering the impact of climate change. It also plans for resiliency by developing a Wastewater Facilities Master Plan and an Energy Strategy Master Plan.
Securing water future
James A. Golab, manager of Innovative Water Technologies (IWT), Texas Water Development Board (TWDB), discussed TWDB’s mission of leading the state's efforts to ensure a secure water future for Texas and its citizens.
To accomplish this goal, TWDB provides water planning, data collection, financial assistance and technical assistance services across the state. IWT was created in 2002 and is focused on alternative water supplies, including aquifer storage and recovery, aquifer recharge, desalination, and water reuse.
The primary goals of IWT are to participate in research and demonstration projects, develop publications and other educational material, and disseminate information to the public through various outreach activities. IWT publishes a biennial report on desalination in Texas for the state legislature and the ninth report in this series was released in 2022.
JB Conant, coatings specialist at Warren Environmental, discussed some of the recent Houston-area projects involving a high-build epoxy coating for protecting and rehabilitating critical infrastructure assets. High-build epoxy is ideally suited to provide structural renewal for deteriorated structures. The product is typically specified in thickness between 125 mils and 250 mils, and exhibits tremendous adhesion to various substrates including concrete, brick, and steel.
Additional features of the product include proven resistance to hydrogen-sulfide-induced corrosion found in aggressive sewer environments and resistance to treatment chemicals, like chlorine and ozone. High-build epoxy excels in protecting and rebuilding concrete, brick, steel, and iron found in today’s collection, conveyance, and treatment systems. The epoxy’s properties include structural enhancement, superior adhesion results and high chemical resistance.
Spray-In-Place Pipe (SIPP), using 100-percent solids epoxy, to reline existing pipelines is gaining popularity in the water industry. SIPP combines computer-controlled, spin-cast application with 100-percent solids, structurally enhancing epoxies to provide a state-of-the-art rehabilitation technique. A host pipe is thoroughly prepped (scraped and cleaned with high-pressure water blasting) and then relined with an epoxy certified for potable water. SIPP brings several benefits to rehabilitation projects, including cost and time savings, and a minimal construction footprint.
Conant presented a recent SIPP rehabilitation case study involving repair of 400 linear feet of 24-inch cast iron water pipe in the City of Houston’s congested downtown area. The highly corroded and tuberculated pipe with cavitations was cleaned, patched, and restored with 100-percent solids epoxy by an experienced SIPP contractor. Despite challenges, water service was restored within four days. The result was a plasticized, non-porous interior that prevents further tuberculation or encrustation.
Tracy Brettmann, executive vice president, A.H. Beck Engineering, delivered the 18th Mike O’Neill Lecture on “Lessons Learned from Mike O’Neill and its Impact on Current Practice.” Brettmann worked with O’Neill on three industry-related research projects involving deep foundations and has continued to apply the lessons learned to his practical research during his entire career.
This was followed by C. Vipulanandan’s presentation on “Characterizing Piezoresistive Smart Cement Modified with Silicon Dioxide Nanoparticles Using Vipulanandan Models for Multiple Applications.”
Cement has been used for multiple applications in the construction and petroleum industries, and there is need for further enhancement of the sensing properties and mechanical properties of the cement. In this study, highly sensing chemo-thermo-piezoresistive “smart” cement was modified with up to 1 percent silicon dioxide nanoparticles (Nano Silica -NanoSiO2) to evaluate the effects, on the sensing properties and also on the compressive stress-strain relationship, strength and modulus. The oilwell cement (class H) and cement modified with NanoSiO2 were characterized using the X-ray diffraction analysis (XRD) and thermal gravimetric analysis (TGA).
Smart cement was prepared by adding 0.1 percent carbon fibers (CF), based on the cement weight and new Vipulanandan piezoresistive theory, to make the cement a piezoresistive but, still, a nonconductive material. Testing evaluated the smart cement behavior with and without NanoSiO2, in order to verify the sensitivity of electrical resistivity changes with curing time and compressive loading. The addition of 0.5 percent and 1 percent NanoSiO2 increased the initial electrical resistivity of the smart cement by 17 percent and 35 percent, respectively. Hence, electrical resistivity is a material property that can be used as a quality control parameter for mixing in the field.
The Vipulanandan p-q curing model predicted the changes in electrical resistivity with curing time very well. The smart cement piezoresistive axial strain at failure with NanoSiO2 was over 500 times higher than the regular cement depending on the curing time and NanoSiO2 content. But the piezoresistive axial strain at failure for the smart cement reduced with the addition of NanoSiO2.
The Vipulanandan p-q stress-strain model and stress-piezoresistive strain model also predicted the experimental results very well. For the smart cement modified with NanoSiO2, the resistivity change at peak stress was over 1,250 times (125,000 percent) higher than the change in the compressive strain. Also, a linear correlation was obtained between RI24hr and the compressive strength of the NanoSiO2-modified smart cement, based on the curing time.
Follow-up, path forward
A reception followed the technical sessions in the Exhibit area, where posters were displayed on research activities at CIGMAT and in the Department of Civil and Environmental Engineering. Grouting, pipe manufacturing, material suppliers, pipe condition monitoring, geotechnical engineering and wastewater rehabilitation companies participated in the exhibition.
CIGMAT 2024 conference Proceedings was published and is posted on the CIGMAT website. The next CIGMAT conference (CIGMAT-2025) will be held on March 7, 2025, at the University of Houston-University Hilton.
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