22 Apr 2026

Mesoscale Modeling and Parametric Studies of Concrete Materials

Abstract: This research focused on creating a mesoscale finite element model of concrete, treating it as a three-phase composite material composed of coarse aggregates, mortar, and the Interfacial Transition Zone (ITZ). The objective was to understand how these mesoscale structures influence the material's properties and responses under various loading conditions. The model simulated a normal-strength concrete with a compressive strength of approximately 27 MPa. The simulations included unconfined uniaxial compression, hydrostatic compression, uniaxial strain compression and triaxial compression, with the model's dimensions and boundary conditions mirroring those of laboratory tests on cylindrical specimens. The results from the simulations corresponded well with experimental data, validating the accuracy of the modeling method. Further parametric studies were conducted to examine how attributes like aggregate volume fraction and material properties impact the concrete's overall performance. This validated modeling provides a reliable pathway for optimizing concrete materials for specific uses, such as designing hardened structures for military applications. It also offers a method for estimating concrete properties when laboratory testing is limited or unavailable.

22 Apr 2026

Laboratory Performance Evaluation of Coarse Aggregates for Asphalt Concrete Mixtures

Abstract: An extensive laboratory evaluation was conducted to investigate the performance of coarse aggregates under different test methods. Test methods including the Los Angeles abrasion (LAA), sulfate soundness, Micro-Deval abrasion, aggregate crushing value, aggregate impact value, aggregate durability index, and aggregate slake durability were chosen to determine the aggregates’ resistance to abrasion, impact, crushing, and soundness. A total of twenty-five aggregate sources were included in the laboratory experiments, including seven different aggregate types (crushed gravel, gabbro, greywacke, granite, limestone, monzonite, and sandstone). The mineral composition of the aggregate sources was determined using X-ray diffraction (XRD) analyses. According to this study, the LAA test results were reasonable in screening out an aggregate source perceived as marginally resistant to abrasion. The sulfate soundness test results were ineffective in quantifying the quality of the different aggregate sources. Most alternative test methods identified similarly unacceptable aggregate sources, consisting mainly of aggregate types composed of carbonate minerals. Strong statistical correlations were not found among the aggregate test parameters. Recommendations were given to further investigate existing test requirements for the selection of coarse aggregates, particularly when using the sulfate soundness test method.

22 Apr 2026

Validation of the Swift and Quiet Airfield Assessment Device (SQUAAD)

Abstract: The need to rapidly determine the subsurface strength required to support various aircraft loading during contingency operations is critical to the success of tactical missions. Current Air Force Special Operations teams are required to perform this task using the dynamic cone penetrometer (DCP), a destructive test method that requires up to three personnel to operate, is time-consuming and representative of only a small area, requiring multiple tests to evaluate terrain suitable for airfield landing. An alternative, nondestructive methodology to capture the subsurface strength is the Swift and Quiet Airfield Assessment Device (SQUAAD). The purpose of the study presented in this report was to validate the SQUAAD to provide military personnel confidence in the operation and accuracy of the unit with respect to the legacy DCP device. A series of nine full-scale test sections were constructed at the US Army Engineer Research and Development Center’s indoor pavement testing facility. The test results indicate that the SQUAAD requires further testing and evaluation before it can replace the DCP.

22 Apr 2026

Transient Seepage Analysis for Flood Control Embankments

Abstract: Transient seepage analyses, which are becoming more common in practice, carry inherently more complexity compared with traditional saturated steady-state seepage analyses. The results of a four-year remote monitoring investigation were used to investigate common practices used in transient seepage analyses. Initial pore water pressure distributions were found to correspond to predicted infiltration distributions, which were less than typically assumed. The laboratory-measured drying soil water retention curve was found to provide an upper bound to field measurements. Field-measured soil water retention data were found to better correspond to a mean between the laboratory wetting and drying curves. Transient seepage and stability analyses showed that using a drying soil water retention curve resulted in lower factors of safety compared with using a wetting curve. However, a mean curve between the wetting and drying curves proved to be more accurate when compared with representative field measurements. Using unsaturated shear strengths along with conventional saturated shear strengths for levee embankments was found to minimally contribute to the stability factor of safety. Incorporating the findings from this investigation into a transient seepage analysis will help to improve the reliability of the results.

21 Apr 2026

Review of Computational Fluid Dynamics Capabilities to Analyze the Behavior of Amphibious Vessels During Surf-Zone Transit

Abstract: This US Army Engineer Research and Development Center (ERDC), Coastal and Hydraulics Laboratory (CHL) Engineering Technical Note (CHETN) provides an overview of the state of computational fluid dynamics (CFD) techniques for the analysis of amphibious vessels transiting or interacting with the surf zone. In this CHETN we present (1) a background of the problem set, (2) a general discussion of CFD techniques available for the simulation and analysis of waterborne vessel response in water, (3) a discussion of CFD analysis of amphibious vessels in the surf zone, and (4) a discussion of combined scaled and CFD analysis of amphibious vessels in the surf zone.

20 Apr 2026

Multimethod Change-Detection Analysis Using Prithvi-EO-2.0: A Comparative Study of Traditional and Segmentation-Based Approaches for Vector Database Validation

Abstract: This technical note presents an evaluation of the performance of four change-detection methodologies, with a focus on validating and maintaining authoritative vector-feature databases using Earth observation data. In this study, we implemented traditional pixel-to-pixel change detection, feature-data-compliant segmentation, pixel-to-feature segmentation, and feature-to-pixel change detection, leveraging the Prithvi-EO-2.0 Vision Transformer model (Szwarcman et al. 2025), to analyze imagery from California’s Central Valley. The analysis of Sentinel-2 imagery from California’s Central Valley (in 2021–2023) demonstrated that there was a trade-off between sensitivity and reliability in the change-detection approaches: feature-to-feature methods achieved the highest sensitivity (0.637 average), while the feature-to-pixel approach provided the most reliable validation (0.280 average), exceeding the performance of traditional pixel-to-pixel methods (0.256 average).

20 Apr 2026

Utilizing Laser Diffraction for Soil Particle Size Analysis

Abstract: This US Army Engineer Research and Development Center (ERDC) technical note (TN) describes the process and methodology for utilizing laser diffraction to analyze soil samples. The effort fulfills an Intelligent Environmental Battlefield Awareness (IEBA) project’s need to validate the performance of a global soil boundary mapping methodology that was developed as part of the Integration task. To validate the methodology, soil samples were classified by grain size into a texture class and compared against soil maps created for a given study area. The goal of this effort was to develop a repeatable standard operating procedure for the Horiba Partica LA-960V2, a laser diffraction particle size analyzer, that would allow rapid soil analysis to be conducted by individuals without a soil science background. The Horiba Partica has been used for soil particle size analysis, but it is not common in the field. Therefore, only limited documentation details the analysis protocol for the system. This TN will discuss the methodology used to analyze soil samples and the challenges encountered with the Horiba Partica.

20 Apr 2026

Effects of Environmental Chemical Pollutants on Microbiome Diversity: Insights from Shotgun Metagenomics

Abstract: Chemical exposure in the environment can adversely affect the biodiversity of living organisms, particularly when persistent chemicals accumulate over time and disrupt the balance of microbial populations. In this study, we examined how chemical contaminants influence microorganisms in sediment and overlaying water samples collected from the Kinnickinnic, Milwaukee, and Menomonee Rivers near Milwaukee, Wisconsin, USA. We characterized these samples using shotgun metagenomic sequencing to assess micro-biome diversity and employed chemical analyses to quantify more than 200 compounds spanning 16 broad classes, including pesticides, industrial products, personal care products, and pharmaceuticals. Integrative and differential comparative analyses of the combined datasets revealed that microbial density, approximated by adjusted total sequence reads, declined with increasing total chemical concentrations. Protozoan, metazoan, and fun-gal populations were negatively correlated with higher chemical concentrations, whereas certain bacterial and archaeal populations showed positive correlations. As expected, sediment samples exhibited higher concentrations and a wider dynamic range of chemicals compared to water samples. Varying levels of chemical contamination appeared to shape the distribution of microbial taxa, with some bacterial, metazoan, and protozoan populations present only at certain sites or in specific sample types. These findings suggest that microbial diversity may be linked to both the type and concentration of chemicals present. Additionally, this study demonstrates the potential roles of multiple microbial kingdoms in degrading environmental pollutants, emphasizing the metabolic versatility of bacteria and archaea in processing complex contaminants such as polyaromatic hydrocarbons and bisphenols. Through functional and resistance gene profiling, we observed that multi-kingdom microbial consortia—including bacteria, fungi, and protozoa—can contribute to bioremediation strategies and help restore ecological balance in contaminated ecosystems. This approach may also serve as a valuable proxy for assessing the types and levels of chemical pollutants, as well as their effects on biodiversity.

20 Apr 2026

New Poe Lock Emergency Closure System Physical Model Study

Abstract: The US Army Corps of Engineers (USACE)–Detroit District (LRE) has begun the process of designing a new emergency bulkhead for Poe Lock in Sault Ste. Marie, Michigan, and has requested assistance from the US Army Engineer Research and Development Center, Coastal and Hydraulics Laboratory, in determining the hydraulic loads the bulkhead will experience during operation. The US Army Engineer Research and Development Center has constructed a 1:25 scale physical hydraulic model to estimate the hydraulic forces on the bulkhead and pressure on the bulkhead sill during lowering operations. Multiple bulkhead lowering speeds and bulkhead lip designs have been tested over the course of the study. This report provides time histories of the hydraulic loads and bulkhead pressures throughout the bulkhead lowering operations. These results will inform the design of the emergency bulkhead and the size of its operating equipment.

20 Apr 2026

Surf Zone Hazards Before and After a Beach Nourishment in Virginia, USA

Abstract: Beach nourishment is the leading coastal protection technique in the United States to combat erosion, enhance resilience to storm surge, and maintain recreational value. Despite these benefits, anecdotal reports suggest that beach nourishments elevate the surf zone hazard to beach patrons by steepening the beach face and altering the shoreface morphology such that conditions are more favorable for rip current formation. This study analyzes lifeguard rescue reports collected on the United States Atlantic Coast before and after a 2019 beach nourishment in Virginia Beach, Virginia, to assess whether the nourishment was correlated with an increased hazard to beach patrons. The data indicate that regardless of nourishment status, rescues were most probable during periods of high rip current probability (moderate to large wave heights and low-obliquity wave angles), along with low water level. To formally quantify pre-versus post-nourishment hazards, the proportion of rescues observed in nourished versus unnourished beach zones was compared with bootstrapped distributions of the pre-nourishment rescue proportions. Although the proportion of rescues in the nourished section of the beach exceeds the pre-nourishment average, it is not outside the overall range of pre-nourishment values obtained by random resampling. Consequently, there is insufficient evidence to conclude that the existing coastal management beach nourishment strategy increased the hazard to beach patrons at Virginia Beach.