26 Apr 2021

Automated Construction of Expeditionary Structures (ACES): Materials and Testing

Abstract: Complex military operations often result in U.S. forces remaining at deployed locations for long periods. In such cases, more sustainable facilities are required to better accommodate and protect forward-deployed forces. Current efforts to develop safer, more sustainable operating facilities for contingency bases involve construction activities that require a redesign of the types and characteristics of the structures constructed, that reduce the resources required to build, and that decrease the resources needed to operate and maintain the completed facilities. The Automated Construction of Expeditionary Structures (ACES) project was undertaken to develop the capability to “print” custom-designed expeditionary structures on demand, in the field, using locally available materials with the minimum number of personnel. This work investigated large-scale automated “additive construction” (i.e., 3D printing with concrete) for construction applications. This report, which documents ACES materials and testing, is one of four technical reports, each of which details a major area of the ACES research project, its research processes, and its associated results. There major areas include System Requirements, Construction, and Performance; Energy and Modeling; Materials and Testing; Architectural and Structural Analysis.

5 Nov 2020

Army Installations of the Future Industry Day 2019: Summary Report

Abstract: The Army Installations of the Future Industry Day was held on 23 May 2019 at the Renaissance Capital View hotel in Arlington, VA to identify the availability and maturity of specific commercial off-the-shelf (COTS) “smart installation” capabilities, technologies, and products; and to seek interest from industry in exploring potential approaches, requirements, standards, and/or specifications for pilot demonstrations at Army installations focused on 10 use-case technology areas. The Industry Day event included approximately 336 participants comprised of Academia (5), Industry (226), and Government (105). This report presents “road maps” that outline the Army’s desired outcomes for the target technology areas and potential pilot technology demonstrations.

14 Oct 2020

Estimating the Density of Secretive, At-risk Snake Species on DoD Installations Using an Innovative Approach: IDEASS

Abstract: The Department of Defense (DoD) expends considerable resources managing and conserving threatened, endangered, or at-risk snake species. Management for these species is often hampered by a lack of basic knowledge regarding their population size and trajectory. The low detectability of most snakes makes it difficult to determine their presence, or to employ traditional methods to estimate abundance. This work demonstrated a novel, simulation-based method, Innovative Density Estimation Approach for Secretive Snakes (IDEASS), for estimating snake density based on systematic road surveys, behavioral observations of snake movement, and spatial movement (radio telemetry) data. This method was used to generate meaningful density estimates for two rare and cryptic snakes of conservation concern, the Southern Hognose and Eastern Diamondback Rattlesnake, at Fort Stewart, Georgia. IDEASS was also applied to an existing dataset to retroactively estimate density of a more common species of management concern, the Western Ratsnake, at Fort Hood, Texas. In all three cases, traditional density estimation via visual surveys and capture-mark-recapture (CMR) failed completely due to lack of captures and re-captures, despite extensive field effort. We conclude that IDEASS represents a powerful tool, and in some cases the only viable method, for estimating density of secretive snakes.

14 Oct 2020

The Demonstration and Validation of a Linked Watershed-Riverine Modeling System for DoD Installations – Patuxent Watershed, Maryland

Abstract: This work evaluated a linked watershed and riverine modeling system for the Patuxent River Watershed, Maryland against observed field data and model output from a watershed model. The performance objectives were computed for streamflow, sediment, total phosphorus, orthophosphorus, total nitrogen, ammonium, and nitrate using daily and monthly average model predictions and measured data. Hydrological Simulation Program – Fortran (HSPF) was used to compute runoff, sediment, and nutrient loadings, whereas the Hydrologic Engineer Center – River Analysis Sys-tem (HEC-RAS) was used to evaluate in-stream flow, channel sedimentation, and the fate/transport of nutrients. Model results were successful for calibration, validation, and management scenario analysis. Contaminants were not simulated for this watershed due to a lack of observed data to compare against. The study identified two implementation issues. First, while the Patuxent River did not experience dry bed conditions, where a stream may be intermittent, one can incorporate a very narrow slot at the low point in the cross-section to numerically keep the channel wet during very low flows. Second, to set up the linked model, there needs to be more observed water quality data to better constrain the HSPF output being used as boundary conditions to the HEC-RAS model.

1 Oct 2020

Comparison of Antifungal Efficiencies of Photocatalytic and Antimicrobial-Infused Coatings: Evaluation of Five Antimicrobial Coatings Using Standard Test Methods

Abstract: New buildings are being constructed and existing buildings retrofitted to be more energy efficient to meet increasingly stringent Department of Defense (DoD) energy standards. Although these standards save energy and lower operational costs, they also limit fresh air within a structure and can cause a buildup of harmful substances in indoor environments. Of particular concern are molds, which can put building occupants at risk and damage infrastructure. One possible solution to this increasing Army problem is to coat building materials with photocatalytic paints, which have the ability to both destroy microorganisms as well as the toxic byproducts they produce. This work compared two next-generation photocatalytic coatings against three more traditional antimicrobial-infused coatings for their ability to resist fungal contamination using three accelerated test conditions. Under each test condition the photocatalytic coatings were found to perform poorly compared to the antimicrobial-infused coatings. Moreover, the control coating, which contained no active antimicrobial (standard latex paint), performed as well as or better than all the antimicrobial coatings tested. This suggested that there may be little benefit to using antimicrobial coatings to inhibit fungal colonization over a standard latex paint; however, further testing is required to confirm this perception.

11 Aug 2020

PUBLICATION NOTICE: Army Installation Makerspaces in the Morale, Welfare, and Recreation (MWR) Operational Environment: A Business Case Analysis

Abstract:  This work demonstrated the implementation of makerspaces, collaborative workspaces that provide hands-on learning to help prepare the future workforce with critical 21st century applied-technology skills. Researchers from the U.S. Army Engineer Research and Development Center, Construction Engineering Research Laboratory (ERDC-CERL) enhanced and evaluated the pre-existing makerspace at Fort Bliss, Texas to demonstrate the value of a makerspace within the military Morale, Welfare, and Recreation (MWR) environment. The 8-month pilot demonstration, conducted from May to December 2018, focused on investigating program characteristics such as usage trends, optimal locations, equipment, and personnel access. Results from the demonstration indicated that enhanced makerspaces with high quality equipment had a positive Soldier impact. The business case analysis determined that the Fort Bliss Makerspace fits the criteria of, met the 15% cost-to-revenue ratio threshold for, and can operate successfully as, a Category Type A (Mission Sustaining) program asset.

10 Jun 2020

PUBLICATION NOTICE: Full-Scale Testing of Commercially Available Cementitious Backfill and Surface Capping Materials for Crater Repairs

Abstract: The Air Force Civil Engineer Center (AFCEC) Rapid Airfield Damage Recovery (RADR) program currently utilizes rapid-setting flowable fill (RSFF) and rapid-setting concrete (RSC) for backfilling and capping crater repairs. These materials have been proven successful through many full-scale tests, troop demonstrations, and live flight trafficking. However, only one proprietary product is currently approved for each material. Two candidate capping materials and one backfill material were evaluated by conducting simulated crater repairs and collecting appropriate data. For capping products, both small (8.5 ft x 8.5 ft) and large (15 ft x 15 ft) repairs were conducted and trafficked with simulated F-15E aircraft traffic. For the backfill material, three small repairs were backfilled and the California Bearing Ratio (CBR) was estimated at cure times of 0.5, 2, and 24 hr. Overall, repairs capped with Western Materials Fastrac 246 failed after only 2,000 passes, so the material is not currently recommended for approval. Repairs capped with Buzzi Unicem Ulti-Pave3® were able to sustain 3,500 passes before trafficking was ceased, so this material is recommended for approval as a crater repair capping material. CTS rapid-setting flowable fill backfill exhibited lower than expected CBR values and did not allow timely percolation of mix water, so it is not currently recommended for approval at this time.

30 Apr 2020

PUBLICATION NOTICE: Effects of Boric Acid and Water Content on Fundamental Properties of Proprietary Magnesium Phosphate Cement (MPC) Products

Abstract: Magnesium phosphate cements (MPCs) have been used for decades in proprietary products for pavement repairs. However, products with high exothermic temperatures have short working times, and research is needed to overcome these unfavorable characteristics. The effects of different boric acid and water contents on the fundamental properties of concrete was investigated through 34 trial batch modifications on the following commercially available MPC products: (1) Premier Magnesia’s PREMag PGDM, (2) BASF Master Builder’s MasterEmaco T545, and (3) CeraTech Inc.’s Pavemend TR. Overall results indicated that the increase of boric acid and water content produced favorable decreased temperatures and increased set times but retardation in the early age development of compressive strength. Modifications in the PREMag PGDM product resulted in poor workability, inaccurate time of setting due to a thixotropic nature, and unacceptable compressive strength loss. The Pavemend TR product was significantly affected by the addition of boric acid resulting in nonrecoverable compressive and bond strength loss, excessive expansions, failure at low freezing and thawing cycles, and unacceptable times of setting for rapid-repair applications. The T545 product showed promising performance with 28-day recovery in compressive, flexural, and bond strengths and minimal differences in other properties when compared to the control mixture.

29 Apr 2020

PUBLICATION NOTICE: Laboratory Characterization of Rapid-Setting Flowable Fill

Abstract: Utility Fill One-Step 750® is a rapid-setting flowable fill product that has previously been validated in numerous full-scale demonstrations as an expedient backfill solution for Rapid Airfield Damage Recovery. Although the field performance of Utility Fill One-Step 750® has been extensively documented, a full laboratory characterization has not been conducted. This report analyzes and documents results from several laboratory tests conducted at two water to-product ratios. The tests conducted are based on the suite of tests that make up the triservice spall repair certification program used for rapid-setting concrete products. Tests include strength and set time-related properties, typical parameter control tests for concrete, and tests to determine the mineralogy and chemical makeup of the material. Long-term expansion and contraction properties were also tested. The data presented herein are intended to provide an overall assessment of Utility Fill One-Step 750® and to provide reasonable estimates of various design parameters. The results can be used as a basis for the future development of a formal laboratory certification protocol to down-select other rapid-setting flowable fill products for further evaluation.

23 Apr 2020

PUBLICATION NOTICE: Conspecific Attraction as a Management Tool for Endangered and At-Risk Species on Military Lands

Abstract: Movements of wildlife species and associated colonization of habitats is often unpredictable, potentially leading to ineffective management and/or interference with military training. Habitat restoration for wildlife management on military lands is a common, yet expensive, response to federal conservation and mitigation mandates, yet viable wildlife populations often fail to become established on restored habitat. Conspecific attraction, using the tendency for individuals of the same species to settle near one another, can be a cost-effective means of attracting animals to newly created or restored habitats. This work demonstrated the use of conspecific attraction as an alternative tool for encouraging colonization of restored habitats by at-risk birds and amphibians. Conspecific attraction was relatively straightforward to employ, but its effectiveness varied among species. We demonstrated clear success in attracting some bird (northern bobwhite; Colinus virginianus) and frog (wood frogs; Lithobates sylvaticus) species into our target areas but other species showed a neutral response. Conspecific attraction presents a cost-effective alternative to current management practices such as translocation or colonization after habitat is created or restored. Only minimal equipment costs (<$300/broad-cast station) and nominal work-hours are required to set up the equipment, and total cost was ~$1,200 per demonstration plot annually.