29 Jan 2026

A Monolithically Coupled Surface Water and Groundwater Finite Element Model with Fully Implicit Time Stepping Using Adaptive Hydraulics (AdH) v5.0 (KraRE: 21428 (ken)

Abstract: Simulation of surface water and groundwater interaction is becoming increasingly important for the US Army Corps of Engineer Civil Works and Military Missions. This report details the formulation of a monolithic, coupled approach that combines the Richards equation for variably saturated groundwater flow and a diffusive wave approximation for overland flow. The model is implemented with USACE’s Adaptive Hydraulics (AdH) computational framework and is evaluated for several community benchmark problems. The results indicate that the AdH model is stable with performance similar to existing, well-established codes for surface water and groundwater interaction.

29 Jan 2026

Composite Materials for Sector Gates and Vertical Lift Gates: Report of FY22–FY24 Project Outcomes

Abstract: This project supported a Statement of Need (SON) submitted to the Navigation Research Area Review Group: SON 2021-1505 by David Weston, Business Line Manager for Inland Navigation (INAV) and Flood Risk Management (FRM) at Jacksonville District. The goal of this study was to provide design guidance, criteria, and performance standards for professionals to use in the design, retrofit, maintenance, and repair of Canaveral sector gates and W. P. Franklin vertical lift gates using structural grade fiber-reinforced polymer (FRP) composites. The results also contribute to guidance documentation used for Hydraulic Composite Structures at other INAV structures. Our work focused on four main subject areas: direct field support, workforce education, structural connection design and modal analysis, and inspection guidance. As this research project progressed through three FYs in coordination with stakeholders across the US Army Corps of Engineers (USACE) and industry, the Inland Navigation Design Center (INDC) and the Jacksonville District gained competency in hydraulic composite structures design techniques, which enabled their successful award of a contract for composite bulkheads at Port Mayaca and vertical lift gates at W. P. Franklin.

28 Jan 2026

Unpiloted Aerial System–Borne Ground-Penetrating Radar for Snow Depth Estimation in Mountainous Warfighter Domain

Abstract: We demonstrate the latest capability in unpiloted aerial systems (UAS) ground-penetrating radar (GPR) measurements for snow depth estimation in mountainous terrain. Several technical considerations are important for successful data collections such as aircraft radio frequency link interference. We found that a 2.4 GHz ground control station to aircraft link frequency maintains independence from the 0−1.5 GHz bandwidth of the Zond Aero 500 GPR. Between flights at 2 m and 4 m above ground level (AGL), the footprint of the radar signal on the ground increases by approximately 25%, which increases off-nadir scattering and reduces reflection coherence. We developed an automated layer detection tool to identify air-snow and snow-soil interfaces within the radar signal and estimated snow depth using these automated signal interpretation methods and user-guided interpretations for validation. We found that flights conducted at 2 m AGL resulted in more precise snow depth estimates (21 cm [7%] uncertainty) than flights conducted at 4 m AGL (34 cm [12%] uncertainty). We estimated snow depth with UAS-GPR; however, with further development, this technique can inform near-real-time retrievals of additional snow properties critical to vehicle mobility within the warfighter domain.

28 Jan 2026

Lightweight Deflectometer (LWD) Evaluation of Low Volume Road Structural Deterioration Under Military Traffic Loads

Abstract: In a combat zone, military vehicles may not have the benefit of traveling on well-constructed pavements, necessitating the use of low volume roads (LVR) to transport personnel and cargo. Military vehicles can cause rapid structural damage to LVRs that are not designed to withstand increased traffic loads. Currently, rapid pavement infrastructure assessment techniques for military personnel are based on qualitative visual inspections which do not provide estimates for structural capacity of the pavement. The objective of this project was to determine whether the lightweight deflectometer (LWD) can be used as a structural evaluation tool for LVRs in contingency operations. This study explored the capability of LWD equipment in evaluating factors that influence flexible pavement structural capacity: load-induced deterioration, soil moisture, and asphalt temperature. Falling-weight-deflectometer (FWD) and LWD tests were performed to measure pavement structural condition. The LWD was shown to be applicable for LVRs experiencing military traffic. The LWD is portable, simple to use, and more suitable than the FWD for LVRs when high rut depths are permitted. LWD data trended similarly to FWD data and therefore can be recommended as an alternate to the FWD in assessing the structural condition of LVRs for contingency planning.

27 Jan 2026

Procedure for Determining the Thermal Properties of Asphalt Binder

Purpose: This technical note documents a testing procedure developed and used by the US Army Engineer Research and Development Center (ERDC) to measure the thermal properties of asphalt binder. While these properties can be measured using specialized precision equipment that is unavailable in most asphalt testing laboratories, no standardized test methods exist to determine the thermal properties of asphalt binder. The test method described herein employs user-friendly equipment to measure the thermal properties of interest. The repeatability of the test procedure was evaluated on samples of asphalt binder blended with varying amounts of graphite and was found to be acceptable.

27 Jan 2026

Evaluation of European Rapid-Setting Concrete Products for Airfield Repairs

Abstract: The USAF is assessing European cementitious repair products to certify them for spall and crater repairs on airfield pavements. As part of this ef-fort, the USAF asked the US Army Engineer Research and Development Center (ERDC) to evaluate and test three European-manufactured rapid-setting materials at the Silver Flag Exercise Site, Ramstein Air Base, Germany. ERDC evaluated and tested two cementitious products manufactured by Concretum, a company in Switzerland (country code CH), and one product, AC Concrete Rapid Set, from CTS Cement Manufacturing Corporation. The product was provided by Korodur International, a German (country code DE) distributor. Rapid pavement repair activities are critical to economically and efficiently sustaining airfield operations with existing pavement infrastructure. Repairing spalls and craters in Portland cement concrete airfield pavements will help lower repair costs from aircraft impact damage and prolong the service life of the pavement, ultimately saving money over its lifespan. Numerous partial-depth spall and full-scale crater repairs were constructed along existing inner and outer slab joints and backfilled with rapid-setting cementitious repair products following manufacturer mixing requirements.

22 Jan 2026

Knowledge Gaps and Education Opportunities on Direct Potable Reuse: Interviews with Customers of a Large, Southwestern United States Water Utility

Abstract: Water scarcity is a global public health threat that has increased urgency in implementing new sustainable practices to protect water supplies, such as the use of direct potable reuse, or “advanced water purification (AWP)". The study objective was to use interviews to characterize knowledge gaps and community outreach strategies to increase successful AWP implementation in an arid city in the southwestern United States. Through partnership with a water utility in an urbanized area of Arizona, 6000 individuals were emailed for invitation to participate in interviews. Interviews were conducted over Zoom and transcribed verbatim. Transcripts underwent inductive thematic analysis. Twenty-two individuals participated in interviews, and saturation of themes was reached. Five main themes emerged: 1) Conflation of filters with all treatment and the influence of residential technologies, 2) individual-level control over decisions to use advanced purified water, 3) desire for regulation, testing, and transparency about testing results, 4) concerns about specific chemicals, 5) educational resources to strengthen community engagement. Participants expressed lack of knowledge about how water is delivered to their residences by expressing the desire for opting in or out of system-wide treatment approaches.

22 Jan 2026

Carbon Partitioning Effects on Martensitic Phase Transformation of Type 301 Steel Under Various Thermal Processing Conditions

Abstract: Simultaneous improvement of strength and ductility in steels has been a daunting challenge for materials scientists, as these properties are by nature mutually exclusive. One design approach that has the merit to use traditional steel processing technologies is the thermo-mechanical stabilization of the austenitic phase. Owing to its highly symmetric FCC crystal structure, if austenite can be maintained during processing, and then further preserved under mechanical deformation, the final microstructure can solve the Pareto design problem where the high strength does not compromise the ability of the material to resist strain localization/incompatibility. The thermomechanical stability of austenite is achieved through compositional modification of the phase, thereby making the control of the elemental partitioning mechanism between existing phases during manufacturing as the main design metric. In this work, we have developed a phase field framework to model the partitioning mechanism of one of the cheapest austenite stabilizers, carbon, in a 301 stainless steel grade. The model uses a coupled framework between thermomechanical and latent heat effects to capture carbon partitioning during martensite nucleation, propagation, and growth kinetics as well as austenite stability and distribution during and after various heat treatment routines. Various microstructures were simulated for the quench state only as well as quench-and-temper heat treatment routines. The resulting microstructure and carbon distribution shed light on various evolutionary effects such as carbon segregation, grain boundary effects, stable martensite morphology, austenite distribution, and phase fraction. In particular, the model was able to reproduce the evolution of carbon-depleted martensite zones and carbon-enriched austenite regions as well as carbon distribution similar to experimental observation at austenite–martensite interfaces.

22 Jan 2026

Guideposts and Guardrails for Biodiversity Accounting in the 21st Century

Abstract: The new Kunming-Montreal Post-2020 Global Biodiversity Framework (GBF) calls for transformative change to integrate biodiversity and conservation goals into decision-making across public and private sectors. As a result, biodiversity accounting approaches, which reduce the multifaceted complexity of nature to quantitative metrics for practical applications, are proliferating rapidly. These approaches will be essential for implementing growing practices like nature-based solutions, corporate biodiversity stewardship, no net loss policies, and sustainable infrastructure development. In this perspectives article, we identify ten considerations for biodiversity accounting to ground ongoing discourse in sound ecological science and to better integrate biodiversity into societal decision-making. These considerations pertain to three processes within biodiversity accounting: (1) selecting biodiversity targets, facets, indicators, and metrics, (2) tool and framework design, and (3) implementation. For each consideration, we highlight desirable attributes or practices, which we call “guideposts”, and cautionary notes demarcating problems to be avoided, or “guardrails”. These help to delineate the safe design space for creators and users of biodiversity accounting systems to avoid unintended consequences and reduce risks of failing to achieve conservation objectives via misuse or ineffective approaches. Major considerations include the need for careful disclosure of effort and statistical uncertainty, interoperability and flexibility of frameworks, careful justification and explanation of selected facets, metrics, and indicators, and attention to local social and ecological context. Consideration of these guideposts and guardrails could help avoid unintended consequences like accelerated biodiversity loss and exacerbated environmental injustice while providing a practical basis for achieving the sustainable futures envisioned in the GBF.

22 Jan 2026

Assessing Longer-Term Effectiveness of Forest Management Guidelines on Breeding Habitat for Cerulean Warblers

Abstract: Widespread clear-cutting in the late 19th and early 20th centuries and subsequent regrowth has resulted in homogenous, closed-canopy forest structure across much of eastern deciduous forests in temperate North America. Forest management prescriptions designed to diversify stand structure have been increasingly applied with the goal of improving breeding habitat for declining species that require heterogenous forest structure, including Cerulean Warblers (“ceruleans”; Setophaga cerulea). Although a few studies have documented positive short-term (1–4 years post-treatment) responses of ceruleans to forest management prescriptions in the Appalachian Mountains region, longer-term responses have yet to be assessed. In 2019–2020, we followed the same spot-mapping methods as used previously (2005–2006 pre-harvest and 2007–2010 post-harvest) and compared territory density with previous estimates at each of 4 treatment levels (reduced basal area and overstory canopy by 0–75 %) across four forest stands on study sites in Tennessee, Kentucky and Ohio (n = 12 stands total) that had exhibited short-term positive density responses. Ceruleans did not exhibit consistently positive longer-term responses compared with pre-treatment densities when all stands were analyzed together. Compared with pre- treatment surveys, after 13–14 years post-harvest we documented density decreases of 1.0–3.1 territories per 10 ha at 5/9 stands, and positive responses of 1.8–2.2 territories per 10 ha at 3/9 treated stands. Over this period, midstory cover changed significantly (increased) during the 10 years since these stands were last surveyed. Thus, sustaining the short-term (1–4 year) positive response of cerulean warbler territory density to timber harvest may require periodic follow-up treatments that reduce the development of a dense midstory; we recommend that this hypothesis, along with the methods to achieve these conditions, should be tested.