Construction Engineering Research Laboratory Research Articles

Issue Information

Cover Photograph: Epoxy‐coated, chopped, basalt fiber tows obtained from Technobasalt‐Invest (Kiyv, Ukraine). (Upper left) As‐received. Heated at 1,000°C (Upper right) and 1200°C (Lower) for 1 hour at ramp rates of 7.5 °C/min. (https://doi.org/10.1111/jace.17648) Courtesy of Patrick F. Keane, US Army Corps of Engineers, Construction Engineering Research Laboratory, Champaign, IL and University of Illinois at Urbana‐Champaign. image

The Viability and Simplicity of 3D-Printed Construction: A Military Case Study

In November 2019, U.S. Marines, Air Force, and Army Corps of Engineers personnel demonstrated the viability and simplicity of three-dimensionally (3D)-printed construction in a controlled environment at the U.S. Army Engineer Research and Development Center—Construction Engineering Research Laboratory in Champaign, Illinois. The tri-service exercise spanned three days and culminated in the construction of three 1 m × 1 m × 1 m (3 ft × 3 ft × 3 ft) concrete dragon’s teeth (square pyramid military fortifications used to defend against tanks and armored vehicles) and several custom-designed objects. The structural components were printed using a custom-built, gantry-style printer called ACES Lite 2 and a commercially available, proprietary mortar mix. This paper examines the viability of using 3D-printed construction in remote, isolated, and expeditionary environments by considering the benefits and challenges associated with the printing materials, structural design, process efficiency, labor demands, logistical considerations, environmental impact, and project cost. Based on the results of this exercise, 3D-printed construction was found to be faster, safer, less labor-intensive, and more structurally efficient than conventional construction methods: the dragon’s teeth were printed in an average of 57 min each and required only two laborers. However, the use of commercially procured, pre-mixed materials introduced additional cost, logistical burden, and adverse environmental impact as compared to traditional, on-site concrete mixing and production. Finally, this paper suggests future applications and areas of further research for 3D-printed construction.

Development of the construction processes for reinforced additively constructed concrete

In August 2018, a demonstration/experiment was performed in Champaign, Illinois USA, at the Engineer Research and Development Center Construction Engineering Research Laboratory (ERDC-CERL) looking at the continuous printing of a 512 ft2 (47.6 m2) reinforced additively constructed concrete (RACC) building. This building incorporated the capability of 3D-printing to produce unique free-form shapes, while utilizing traditional reinforcing methods. Previously, in July of 2017, a more traditional building was 3D printed using a discontinuous concrete printing approach. These demonstrations were performed to determine the feasibility of using additively constructed concrete (ACC) as a material for vertical structural elements. This study explores the differences and similarities of ACC with conventional concrete construction and concrete masonry unit construction. To validate the feasibility of ACC a cost comparison analysis was performed comparing the construction methods used in these demonstrations to conventional concrete masonry unit and cast-in-place concrete construction.

Black Bears (Ursus americanus) as a Novel Potential Predator of Agassiz's Desert Tortoises (Gopherus agassizii) at a California Wind Energy Facility

Jeffrey E. Lovich,* David Delaney, Jessica Briggs, Mickey Agha, Meaghan Austin, and Jason Reese U.S. Geological Survey, Southwest Biological Science Center, 2255 North Gemini Drive, MS-9394, Flagstaff, Arizona 86001, USA U.S. Army Construction Engineering Research Laboratory, P.O. Box 9005, Champaign, IL 61826-9005, USA Colorado State University, Warner College of Natural Resources, Fort Collins, CO 80523, USA University of Kentucky, Department of Forestry, Lexington, KY 40546

Airtightness in New and Retrofitted U.S. Army Buildings

The Engineer Research and Development Center, Construction Engineering Research Laboratory (ERDC-CERL) recently developed design/construction strategies that improve the energy efficiency, reduce the potential for mould, and improve indoor air quality in newly constructed buildings and buildings undergoing major renovations. ERDC-CERL performed building envelope leakage tests on Army facilities to test their general integrity and the effect of increased airtightness on building energy consumption. Results were used to develop airtightness criteria and performance requirements for new construction and major renovation projects, which have been included in Army design/construction strategies.Since 2009, the U.S. Army Corps of Engineers (USACE) has implemented an airtightness requirement in all new construction and building enclosure renovation projects. Engineering and Construction Bulletin (ECB) 2012–16 set levels of airtightness for building enclosures at the material, assembly, and system level. ECB 2012–16 requires whole building air leakage tests to be conducted at completion of construction to verify the constructed air barrier system’s performance. The current Air Leakage Test Protocol for Building Envelopes developed by ERDC-CERL, the Air Barrier Association of America (ABAA), and other industrial partners was published in May 2012.This paper presents the results of airtightness tests before and after the new requirements were established, updated results for air leakage tests of more than 285 newly constructed and renovated large buildings, and a performance analysis of the design and construction process, air barrier materials, building use, and construction types. These data may support future decisions regarding airtightness levels to be adopted for commercial buildings.

General guidelines to highway agencies to enhance their local pavement rating systems: A case study of nevada’s pavement rating system

Evaluation of pavement condition is the principle source for the effective management of the pavements within any network or state. Many highway agencies within United State are using different pavement rating systems to evaluate their pavement condition. The data collection system, measurement units, calculation techniques have been modified and updated by several states with technological development with time. Recently, several highway agencies are willing to update their old pavement rating systems or gradually switch to more accurate rating systems but facing difficulties. This paper focuses on the potential enhancement on the Pavement Rating Index (PRI) used by Nevada Department of Transportation (NDOT) and thus eventually transitioning to the Pavement Condition Index (PCI) developed by U.S. Army Construction Engineering Research Laboratory. Pavement condition data that were utilized to calculate PRI over the last 15 years were converted into PCI compatible format using a suitable conversion technique. Estimated PCI values were plotted against its corresponding PRI showed moderate correlation with R² value of 0.57. The current PRI system was then enhanced to eliminate the observed deficiencies in the current system. The statistical relationship between the enhanced PRI against PCI showed improved correlation with R² value of 0.78. The study concluded that a successful switch from PRI system to PCI system can be achieved in Nevada while maintaining the use of the historical pavement condition data. This paper provides general recommendations for other agencies that are transitioning from local pavement rating system to PCI system.

Acoustic Leak Survey of the Underground Potable Water System at a CONUS Army Installation

U. S. Army Corps of Engineers Engineer Research and Development Center, Construction Engineering Research Laboratory (ERDC-CERL), and Carlyle Consulting’s John Carlyle conducted a leak detection survey at a U.S. Army Installation. The age of pipes in the distribution system ranged from 20 to 60 years. The thrust of the work was to acoustically survey all of the underground pipelines constituting the installation’s potable water distribution system and find any leaks. The results of the survey were that 6 leaks were discovered in the main lines, 63 leaks associated with fire hydrants, freeze proof hose bibs, water meters, etc., and 33 leaks inside buildings. Over two thousand acoustic measurements were made in order to obtain these results.

Carbonate Direct Fuel Cell Operation on Dual Fuel

The ability to operate highly-ef ficient, pollution-free, distributed-generation power plants on either natural gas or HD-5 grade propaneis of interest to the U.S. Army and the U.S Department of HomelandSecurity as secure power source for critical power operations. The abil-ity to operate continuously on HD-5 propane also provides a valuableproposition to islands, remote sites, national parks, data centers, militarybases, hotels, and hospitals. HD-5 propane, as opposed to other gradesof propane, was selected as the back-up fuel of choice because of itsavailability (even in remote areas), cost, and ease of processing in thefuel cell power plant. Although natural gas distribution through utilitypipelines is convenient, it is vulnerable to natural disaster, threats ofterrorism, and simple repair outages. Propane, however, is routinelytransported and stored as a liquid at ambient temperatures and offersa convenient and secure option for fuel cell operations. An adequatequantity of propane can be stored on site to sustain operations for sev-eral days in a variety of weather climates.In response to the interest for a fuel flexible power plant, Concur-rent Technologies Corporation (CTC), under contract to the U.S. ArmyEngineer Research and Development Center’s Construction EngineeringResearch Laboratory (ERDC-CERL), is working with FuelCell Energy(FCE) to test an internally reforming 250 kW carbonate fuel cell. Previousto the demonstration at CTC, FCE operated a 250 kW carbonate directfuel cell for 1500 hours, which generated 300,000 kilowatt-hours (kWh)net AC electricity using HD-5 propane as fuel. Among the challengesaddressed, lessons learned by FCE during initial operation on HD-5propane included: 1) avoiding carbon deposition during pre-reformingof propane into a methane rich gas, 2) metering and controlling propane flow to account for variations in fuel composition, 3) removing sulfurfrom the propane, and 4) increasing the steam required for operationon propane. Peripheral issues that required additional investigationincluded identifying the number and volume of propane tanks and avaporization system to deliver the required rate and quantity of fuel.

Knowledge-Based Condition Survey Inspection Concepts

The U.S. Army’s Engineer Research and Development Center—Construction Engineering Research Laboratory has developed a “knowledge-based” approach to planning and conducting routine facility inspections. Rather than simply recording deficiencies on a calendar-based schedule this new approach uses knowledge of facilities to develop and execute a tailored inspection plan for individually defined facility “management units.” This knowledge includes measurable attributes such as facility importance, management unit importance, condition (past, present, and predicted future), desired condition thresholds, and expected asset remaining life. Also, recognizing that there are several inspection objectives to be met at different times in a management unit life cycle, different levels of inspections may be used at different times to attain those objectives. The “knowledge-based condition survey inspection (KBCSI)” approach marries all of these elements together to develop inspection plans for a vast array of facility ...

Seismic Evaluation of Low-Rise Reinforced Masonry Buildings with Flexible Diaphragms

Abstract This paper provides an integrated approach to the seismic evaluation of low-rise reinforced masonry buildings with flexible roof diaphragms. The paper is divided into four phases. In Phase 1 (Behavior), results from shaking-table testing, quasi-static testing, and analytical predictions are integrated to provide a coherent description of the seismic response of low-rise reinforced masonry buildings with flexible roof diaphragms. Two half-scale, low-rise reinforced masonry buildings with flexible roof diaphragms are subjected to earthquake ground motions on the Tri-axial Earthquake and Shock Simulator at the United States Army Construction Engineering Research Laboratory, Engineer Research and Development Center. Following the shaking-table tests, diaphragms and top four courses of attached masonry walls are salvaged from the half-scale structures and tested quasi-statically in their own plane. A new index, the diaphragm drift ratio, is introduced to describe the potential for diaphragm damage. In Phase 2 (Analysis), coordinated analytical modeling is developed and implemented to corroborate and extend the results of that experimental work, and to examine the efficacy and accuracy of different analytical modeling approaches. Linear elastic finite-element models, simplified two-degree-of-freedom models, and nonlinear lumped-parameter models are developed; all agree well with measured responses. In Phase 3 (Seismic Evaluation), the first two phases are used to develop and verify a simple extension to FEMA 310, the predominant seismic evaluation methodology for low-rise reinforced masonry building with flexible diaphragms. In Phase 4 (Application and Verification), the proposed extension, applied to four existing buildings, is shown to be simple, useful, and necessary.

Seismic Evaluation of Low-Rise Reinforced Masonry Buildings with Flexible Diaphragms: III. Synthesis and Application

This paper outlines the last two phases of a joint research study performed by the University of Texas at Austin and the U.S. Army Corp of Engineers, Construction Engineering Research Laboratory, Engineer Research and Development Center (CERL). The study coordinates and synthesizes experimental testing, analytical modeling, practical implementation, and real-world application to enhance FEMA-310, the predominant seismic evaluation methodology for low-rise reinforced masonry buildings with flexible diaphragms. In earlier phases of study, conclusions from shaking-table testing, quasi-static testing, and analytical modeling were used to develop a simple tool for the seismic analysis of these types of buildings. In this paper, the tool is developed in the context of performance-based earthquake engineering into a supplementary evaluation methodology intended to fill a gap in FEMA-310. The tool is applied to four existing buildings and ultimately shown to be simple, useful, and necessary.

Fuel Cell Demonstration at the U.S. Coast Guard Air Station Cape Cod

The U.S. Coast Guard installed one of the first fuel cells in the NewEngland region, with funding from the Green Power Initiative of theRenewable Energy Trust (administered by the Massachusetts TechnologyCollaborative), the U.S. Department of Defense’s (DOD’s) ClimateChange Fuel Cell Program, and KeySpan Energy. Beginning in 1998, theFederal Energy Management Program (FEMP) and the U.S. Army Corpsof Engineers’ Construction Engineering Research Laboratory (CERL)provided technical assistance in the form of project economics, analysis,and site selection.The 250-kW fuel cell combined heat and power plant is located atthe U.S. Coast Guard Air Station Cape Cod in Bourne, Massachusetts.The prime contractor, PPL Corporation, was responsible for all engineer-ing and design work. FuelCell Energy of Danbury, Connecticut, wasresponsible for the manufacture, delivery, and installation of the fuel cell.Fuel cells produce electricity through an electrochemical reactionrather than combustion. While currently more expensive to purchasethan conventional power-generating equipment, fuel cells provide effi-cient, reliable power with minimal emissions. (For more information onfuel cells, see FEMP’s Federal Technology Alert, “Natural Gas Fuel Cells”at www.eere.energy.gov/femp/pdfs/FTA_natgas_fuelcell.pdf).

Fuel Cell Demonstration at the u.s. Coast Guard Air Station Cape Cod

ABSTRACT The U.S. Coast Guard installed one of the first fuel cells in the New England region, with funding from the Green Power Initiative of the Renewable Energy Trust (administered by the Massachusetts Technology Collaborative), the U.S. Department of Defense's (DOD's) Climate Change Fuel Cell Program, and KeySpan Energy. Beginning in 1998, the Federal Energy Management Program (FEMP) and the U.S. Army Corps of Engineers' Construction Engineering Research Laboratory (CERL) provided technical assistance in the form of project economics, analysis, and site selection. The 250-kW fuel cell combined heat and power plant is located at the U.S. Coast Guard Air Station Cape Cod in Bourne, Massachusetts. The prime contractor, PPL Corporation, was responsible for all engineering and design work. FuelCell Energy of Danbury, Connecticut, was responsible for the manufacture, delivery, and installation of the fuel cell. Fuel cells produce electricity through an electrochemical reaction rather than combustion. While currently more expensive to purchase than conventional power-generating equipment, fuel cells provide efficient, reliable power with minimal emissions. (For more information on fuel cells, see FEMP's Federal Technology Alert, “Natural Gas Fuel Cells” at www.eere.energy.gov/femp/pdfs/FTA_natgas_fuelcell.pdf).

Seismic Evaluation of Low-Rise Reinforced Masonry Buildings with Flexible Diaphragms: I. Seismic and Quasi-Static Testing

This and a companion paper compare the results from shaking-table testing, quasi-static testing, and analytical predictions, to provide a coherent description of the seismic response of low-rise reinforced masonry buildings with flexible roof diaphragms. Two half-scale, low-rise reinforced masonry buildings with flexible roof diaphragms are subjected to earthquake ground motions on the Tri-axial Earthquake and Shock Simulator at the United States Army Construction Engineering Research Laboratory, Engineer Research and Development Center. Following the shaking-table tests, diaphragms and top four courses of attached masonry walls are salvaged from the half-scale structures and tested quasi-statically in their own plane. In contrast to what is usually assumed in design, the half-scale specimens do not behave as systems with a single degree of freedom associated with the in-plane response of the shear walls, but rather a system with a dominant degree of freedom associated with the in-plane response of the roof diaphragm. A new index describing the potential for diaphragm damage is introduced, the diaphragm drift ratio. A companion paper, Part II: Analytical Modeling, presents analytical work intended to corroborate and extend results from experimental testing.

Design Review Checking System with Corporate Lessons Learned

Design reviews are critical to the success of a construction project. They eliminate costly rework and conflicts, and promote creative and innovative design and construction. This paper discusses a unique way to improve design reviews by gathering and including direct corporate experience that can be used company- and industry-wide. The Design Review Checking System (DrChecks) and the system called Corporate Lessons Learned (CLL) were developed by the U.S. Army Construction Engineering Research Laboratory to collect personal experiences and lessons learned on projects and incorporate these data into corporate knowledge, expressly for the design review process. DrChecks provides a framework for a standardized review process. Typically, exchanges of personal experience and knowledge have occurred informally by word of mouth. With DrChecks and CLL, direct personal experience can be collected into a database while the design review process is on-going. Lessons learned, success stories, and good work practices, which can be identified easily by experienced staff members, can then be shared throughout the organization. DrChecks and CLL both take advantage of the Internet and facilitate the management of design review process and the collection and reuse of corporate lessons learned asynchronously and remotely.

Nuvera to demo PEM fuel cells for Coast Guard

The US Department of Defense has selected Nuvera Fuel Cells to demonstrate its newest product prototype, an Avanti ™ 4 kWe natural gas fuel cell system, at the US Coast Guard facility in Bristol, Rhode Island. The contract was awarded through the Construction Engineering Research Laboratory (CERL), part of the US Army Engineer Research & Development Center. Visit www.re-focus.net for the latest renewable energy industry news

F UEL CELLS PROVIDE RELIABLE POWER TO U.S. P OSTAL SERVICE F ACILITY IN ANCHORAGE, A LASKA

Working together, the U.S. Postal Service (USPS) and Chugach Elec-tric Association, partnering with the Department of Defense (DOD),Department of Energy (DOE), US Army Corps of Engineers ConstructionEngineering Research Laboratories (USA CERL), Electric Power ResearchInstitute (EPRI), and National Rural Electric Cooperative Association(NRECA), developed and installed one of the largest fuel cell installa-tions in the world.The 1-Megawatt fuelcell combined heat andpower plant sits behind theAnchorage U.S. Postal Ser-vice Mail Processing and Dis-tribution Facility. ChugachElectric owns, operates, and maintains the fuel cell power plant, whichprovides clean, reliable power to the USPS facility. In addition, heat re-covered from the fuel cells, in the form of hot water, is used to heat theUSPS Mail Processing and Distribution Facility. By taking a leadershiprole, the USPS will save over $800,000 in electricity and natural gas costsover the 5 1/2-year contract term with Chugach Electric.

Fuel Cells Provide Reliable Power to U.S. Postal Service Facility in Anchorage, Alaska

ABSTRACT Working together, the U.S. Postal Service (USPS) and Chugach Electric Association, partnering with the Department of Defense (DOD), Department of Energy (DOE), US Army Corps of Engineers Construction Engineering Research Laboratories (USA CERL), Electric Power Research Institute (EPRI), and National Rural Electric Cooperative Association (NRECA), developed and installed one of the largest fuel cell installations in the world. The 1-Megawatt fuel cell combined heat and power plant sits behind the Anchorage U.S. Postal Service Mail Processing and Distribution Facility. Chugach Electric owns, operates, and maintains the fuel cell power plant, which provides clean, reliable power to the USPS facility. In addition, heat recovered from the fuel cells, in the form of hot water, is used to heat the USPS Mail Processing and Distribution Facility. By taking a leadership role, the USPS will save over $800,000 in electricity and natural gas costs over the 5 1/2-year contract term with Chugach Electric. “Fuel cells solved a handful of problems.,” Cathe Grosshandler, Alaska District Environmental Coordinator, U.S. Postal Service

Plasma arc thermal destruction applications: technology transfer opportunities

Plasma Arc Technology (PAT), an emerging environmental thermal treatment process, has been used to safely and efficiently meet the waste disposal needs of pyrotechnic smoke assemblies, thermal batteries, proximity fuses, contaminated soil and Asbestos Containing Material (ACM). Since 1989, the US Army Construction Engineering Research Laboratories (USACERL) have been active participants in the research and development towards establishing PAT as an efficient, economical and safe hazardous waste immobilisation tool. A plasma torch capable of generating high temperatures makes this technology a viable and powerful tool for the thermal destruction of ACMs into an innocuous ceramic material no longer requiring disposal as a hazardous waste. When pure asbestos is subjected to temperatures above 1000?C, the asbestos fibres melt and subsequently solidify into a nonhazardous, chemically inert, solid material. The resulting processed, rock-like substance meets all Environmental Protection Agency (EPA) criteria as a nonhazardous material and has value as gravel or aggregate material. In addition, research indicates that PAT is a powerful technology for the conversion of unique military hazardous waste contaminated items into inert, vitrified slag. Advantages of plasma arc technology include: the availability of high temperatures; flexibility to operate in either reducing or oxidising environments; low gas requirements, thus low effluent gas volumes; substantial waste volume reduction; the ability to treat a large variety of waste streams; and a saleable by-product. This paper will provide an overview of plasma arc technology and discuss the military's hazardous waste disposal needs.

Measurement of attenuation and speed of sound in soils for the purposes of imaging buried objects

The speed and attenuation of sound vary in different soil types and with different levels of water saturation. Imaging techniques make use of speed and attenuation to range targets and compensate for loss in echo magnitude with depth. Signals from an acoustic source over the range of 2–6 kHz were passed through soil and detected by a coupled hydrophone. Six soil samples were used to represent a range of properties expected to influence acoustic response. Clay ranged from 2%–38%, silt from 1%–82%, sand from 2%–97%, and organic matter from 0.1%–11.7%. The attenuation and propagation speed were determined in the soil as a function of soil moisture and compaction. Attenuation coefficients ranged from 0.12–0.96 dB cm−1 kHz−1. Correlation coefficients were 0.35 (P=0.01) and 0.31 (P=0.03) between attenuation and soil water content and soil bulk density. Propagation speeds ranged from 86 to 260 m<th>s−1. The correlation coefficient with speed was −0.28 (P=0.05) for soil water content and 0.42 (P=0.002) for porosity. Given the attenuation, it is theoretically possible to image objects in soils to 40 cm in depth. [Work supported by U.S. Army Construction Engineering Research Laboratory, Champaign, IL.]