U.S. Military's Joint Rapid Airfield Construction Program

: In support of the U.S. Air Force Air Combat Command, the U.S. Army Engineer Research and Development Center (ERDC) was tasked to develop and test innovative techniques, materials, and equipment for expedient and sustainment repairs of small bomb craters in airfield pavements. This airfield damage repair (ADR) investigation consisted of laboratory testing of selected crater fill and capping materials, as well as full-scale field testing of small crater repairs to evaluate field mixing methods, installation procedures, and repair performance. After 3 hr of cure, each crater was trafficked under controlled traffic conditions to determine the ability of the repairs to support the gross load of an F-15E aircraft. Results of the traffic tests identified multiple repair materials that can be used for expedient and sustainment repairs of concrete airfield pavements. Both the laboratory and full-scale traffic tests were conducted at the ERDC in Vicksburg, MS, from February to November 2006. Experimental results were used to develop ADR criteria for rapidly repairing small craters.

The original California Bearing Ratio (CBR) procedure was developed in the 1940s for the design of flexible pavements. The U.S. Army Corps of Engineers modified this equation in the 1950s for heavy aircraft with multiple wheel gears using a thickness adjustment (α) factor. This “CBR-Alpha” performance model is based on a Boussinesq theory of stress distribution and employs an equivalent single wheel load computation. It has gained international recognition since its implementation in the Aircraft Classification Number computation by the International Civil Aviation Organization in 1983. In recent years, however, criticisms regarding the CBR-Alpha procedure’s inability to accurately predict performance for heavier modern aircraft has led efforts towards its improvement. In the late 2000s, the U.S. Army Engineer Research and Development Center (ERDC) conducted a testing program using the Heavy Vehicle Simulator-Aircraft (HVS-A), where the test data was used for the validation of an improved mechanistic-empirical design procedure. A single wheel gear with high tire pressure and single and dual wheel gears with low tire pressures were programmed into the HVS-A to simulate F-15 and C-17 aircraft traffic, respectively. The HVS-A test data, along with earlier test data from the Federal Aviation Administration (FAA) and ERDC, were used in the development of the “CBR-Beta” procedure. The resulting “CBR-Beta” procedure eliminates the need for the α-factor computation by using Frohlich’s equation. This presentation shows the results of the HVS-A testing program and the reformulation of the CBR procedure, highlighting the contribution of accelerated testing in this effort.

Concrete Masonry Unit (CMU) wall construction is prevalent throughout the United States and the world. While masonry provides adequate strength for conventional design loads, in many circumstances it is inadequate for meeting the minimum standards mandated for blast protection of new and renovated government construction. Protection of military and civilian occupants of masonry structures has received long needed research, due to increased terrorist threat and government mandates for new construction and renovation of federal buildings. The US Army Engineer Research and Development Center (ERDC) has been involved in blast resistant structures r esearch for decades. In the last ten years analytic approaches developed for hardened structures were adapted to terrorist bombings of conventional construction. In addition, simplified response surface based methods, developed to access damage from accidental explosions, were employed to develop models for terrorist bomb attack. These pressure -impulse (P-I) methods were derived from limited data sets and single -degree-of-freedom analytic models. Retrofits to mitigate blast hazard to occupants of masonr y structures have been the focus of recent ERDC research. This research resulted in economical retrofits to reduce debris hazard for occupants rather than to blast -harden the masonry structures. This paper summarizes the development and use of simplified models for the analysis and design of CMU walls and the experimental programs used for model validation.

Near-surface geophysical “targets” include unexploded ordnance (UXO), landmines, cavities (including tunnels and underground facilities), contaminant plumes, utilities (including underground storage tanks, pipelines, etc.), archaeological artifacts, graves, forensic evidence, structural foundation investigations for new and existing structures, and assessing the condition of engineered structures (e.g., bridges, dams, levees, roads, airfields, buildings). Application of near-surface geophysics to detect and characterize any of these “targets” is in the public interest, and many applications are clearly and directly related to public safety. While the detection of these targets in a geologic background can often be challenging, the discrimination of the desired target signatures or expressions from “false alarm” target signatures can be an even greater challenge. The discrimination challenge can be as simple as a “go/no-go” decision on the target, or the properties of the target may need to be further characterized after the decision. There is near unanimity among geophysicists (a rare thing) that multimethod, collocated complementary geophysical data enhance not only target detection but also the capability for discrimination and characterization. The U.S. Army Engineer Research and Development Center (ERDC) conducted a multiyear research and development effort that resulted in complementary, collocated simultaneous geophysical survey capabilities for near-surface targets.

For decades, researchers gradually unveiled the fascinating design principles that give biomaterials extraordinary properties and functionality. The US Army Engineer Research and Development Center (ERDC) is incorporating these design principles to develop hierarchical materials for structural applications. Electrophoretic deposition is one method being explored to create the hierarchical structures. This research details the synthesis of hierarchical nanocomposites composed of calcium carbonate by using electrotransport and electrophoretic deposition to migrate calcium and carbonate ions through a polymer matrix. This process allows better control of the crystal form, size, and location in the polymer matrix, allowing for fabrication of composite materials with optimized mechanical properties for various loading conditions. Other research efforts focused on the use of hydrothermal processing techniques to promote the oriented recrystallization of calcium carbonate. These techniques are being used successfully to fabricate composites for characterization and mechanical testing.

Levees are a fundamental part of many flood-damage reduction projects that protect life and property and their condition and performance in emergency flooding situations is of utmost importance. The U.S. Army Engineer Research and Development Center (ERDC) is conducting research related to levee condition evaluation and assessment. A primary objective of this research is to develop the capability to obtain information about levee conditions and rapidly convey the data to decision-makers during emergency operations, particularly in cases where levee failure is possible. A field study was conducted along a 9-km stretch of the landside levee toe of the Feather River south of Marysville, CA. The purpose of the investigation was to determine the potential of rapidly assessing levee foundations using a variety of geophysical instruments: a Geophex GEM-2 and Geonics EM31 and EM34 electromagnetic (EM) induction tools, a Geometrics OhmMapper capacitively coupled and a Scintrex SARIS direct-current (dc) resistivity system. Electrically non-conductive sleds were built to tow the EM instruments behind a vehicle. The capacitively coupled resistivity system and a combination of the EM instruments provided useful and definitive information for assessing foundation conditions.

This Dredging Operations Technical Support (DOTS) Program technical note presents the results of a study undertaken by the Navigation Branch, US Army Engineer Research and Development Center (ERDC), Coastal and Hydraulics Laboratory (CHL), at the request from the Louisville District (LRL) to examine an incident involving a single vessel and structure in a high-water condition. The vessel-position data used in this request were broadcast from an onboard Automatic Identification System (AIS) transceiver and received by US Army Corps of Engineers (USACE)–owned Lock Operations Management Application (LOMA) tower sites located along the Ohio River.

The U.S. Army Engineer Research and Development Center (ERDC) was tasked by the U.S. Air Force (USAF) to evaluate the capability of emerging nondestructive testing equipment to accurately estimate the thickness of pavement surfaces without requiring large footprint equipment or pavement repairs. The ERDC research team conducted an evaluation of eleven nondestructive technologies, including eight ground penetrating radar devices and three different seismic technologies, on nineteen concrete test locations with varying pavement thicknesses. For each of the different pavement types, a single core was extracted to provide calibration points. The involved vendors and researchers estimated initial thickness, and upon receiving the calibration core thicknesses, final thickness estimates were computed. The accuracy of each technology was quantified by calculating the absolute difference between the actual core measurement and the estimated measurement. This paper describes the eleven different technologies, their performance on the test locations, and comparisons in terms of accuracy and implementation difficulty.

The US Army Engineer Research and Development Center (ERDC) is working collaboratively with the National Oceanic and Atmospheric Administration (NOAA), BGS ITandE GmbH, and the French Naval Hydrographic and Oceanographic Service (Shom) to extend the spectral wave modeling with WAVEWATCH III (WW3) (WW3DG 2019) from global and basin scales (e.g., ERDC Wave Information Studies hindcasting and NOAA forecasting) to local, nearshore processes into the surf zone. WW3 is undergoing rapid community development (Alves, et al. 2023). The unstructured, implicit solution option in WW3 provide flexibility and efficiency to resolve complex shorelines and high- gradient wave zones to drive nearshore circulation, wave setup, and wave-driven sediment transport with multi- scale spatial coverage over approximately three orders of magnitude. A hybrid approach to parallelization uses spectral partitioning for advection in geographical space and domain decomposition for spectral advection and the source term integration. The advection part of wave action equation is integrated fully implicitly, and a new convergent action limiter derived from Komen et al. (1994) and Hersbach and Janssen (1999) is applied. This paper describes model enhancements and validation.

The U.S. Army Engineer Research and Development Center (ERDC) has conducted research on ultra-high performance concretes (UHPCs) since the late 1980 s. The primary focus has been on military and civil works infrastructure applications. The research included the development of a UHPC material called Cor-Tuf Baseline, which includes several derivatives including a patented material. This paper presents the ERDC's historical experience with UHPCs, including constituent materials, laboratory-scale production, and heat treatment, typical microstructure, and pathways for scaling up production. Case studies are also presented on ongoing research focused on the use of fiber-reinforced UHPCs for repair and retrofit of armor plate systems in U.S. Army Corps of Engineers (USACE) inland navigation civil works infrastructure and ongoing long-term field durability testing at the Treat Island Natural Weathering Station near Eastport, ME.

In an effort to identify alternative and beneficial use placement strategies for dredged sediments from the Atlantic Intracoastal Waterway (AIWW), the US Army Corps of Engineers, Savannah District (SAS), and the US Army Engineer Research and Development Center (ERDC) performed a series of physical property tests of 34 core borings from the SAS AIWW. Physical property testing found that 14 of the borings were non-cohesive sandy materials that may be suitable for potential beach renourishment or berm construction. The remaining 20 borings had mud contents sufficient enough to result in cohesive behavior. A subset of six of these materials from across the geographic region were further evaluated to characterize their erosion behavior. Following a self-weight consolidation period of 30 days, erosion testing showed that the tested cohesive sediments had critical shear stress values that ranged from 1.7 Pa to 2.9 Pa, suggesting that these sediments would likely be resistant to erosion in most wetland environments after placement. Additionally, the cohesive sediments were found to produce gravel-sized mud clasts. These clasts could account for 20% or more of the eroded mass and significantly reduce the amount of silts and clays incorporated in suspended plumes during and immediately following placement.

In an effort to identify alternative and beneficial use placement strategies for dredged sediments from the Atlantic Intracoastal Waterway (AIWW), the US Army Corps of Engineers, Savannah District (SAS), and the US Army Engineer Research and Development Center (ERDC) performed a series of physical property tests of 34 core borings from the SAS AIWW. Physical property testing found that 14 of the borings were non-cohesive sandy materials that may be suitable for potential beach renourishment or berm construction. The remaining 20 borings had mud contents sufficient enough to result in cohesive behavior. A subset of six of these materials from across the geographic region were further evaluated to characterize their erosion behavior. Following a self-weight consolidation period of 30 days, erosion testing showed that the tested cohesive sediments had critical shear stress values that ranged from 1.7 Pa to 2.9 Pa, suggesting that these sediments would likely be resistant to erosion in most wetland environments after placement. Additionally, the cohesive sediments were found to produce gravel-sized mud clasts. These clasts could account for 20% or more of the eroded mass and significantly reduce the amount of silts and clays incorporated in suspended plumes during and immediately following placement.

The U.S. Army Engineer Research and Development Center (ERDC) is currently conducting material research on advanced cementitious composites with randomly distributed fiber reinforcement. The successes of the research are well documented, and unconfined compressive strengths on the order of 200 MPa are not uncommon. However, as with most cementitious materials, these materials exhibit a brittle tensile failure response. To improve the material’s response to blast and ballistic loads, the tensile capacity must first be quantified and subsequently enhanced. This paper presents findings of three laboratory experimental series conducted to characterize, quantify, and enhance the tensile failure response of a new rapid-set, field-curable geopolymer concrete that offers distinct advantages over other cementitious composites. Individual fiber, single fiber pull-out, and direct uniaxial tension experiments were conducted for a geopolymer concrete capable of achieving 44 MPa in 24 hours, and 62 MPa in 28 days in ambient temperatures with no additional curing requirements. Three fiber types were examined at various embedment lengths in the matrix. Load versus displacement curves are presented for each type of fiber, as well as the mechanical properties of the fiber itself. Direct tension samples were cast with each type of fiber at 2% by volume in the matrix and tested in a direct uniaxial experiment. The corresponding load versus displacement responses are presented and discussed. Key steps are identified for ongoing research to optimize the fiber matrix interaction, thus maximizing ductility for enhanced material response to tensile forces.

iHMA and RapidPatch are two asphalt repair materials developed at the US Army Engineer Research and Development Center (ERDC) to provide asphalt patching materials that are readily available, support rapid return to traffic, and yield high quality, long-term performance solutions. The primary objective of this project was to complete multiple demonstrations of asphalt patching with iHMA and RapidPatch at four installations in different climate zones around the United States. These locations included Fort Wainwright (Alaska), Fort Drum (New York), Fort Huachuca (Arizona), and Bradshaw Army Airfield (Hawaii). Overall, demonstrations were completed successfully in all climates, providing an opportunity to evaluate patching technologies in real-world environments, some of which are considered untraditional conditions for repairing asphalt. In total, 111 tubes of iHMA and 90 buckets of RapidPatch were used to complete 55.3 ft3 and 49.8 ft3 of patching, respectively, with patch sizes ranging from 4 ft2 up to 20 ft2. Both iHMA and RapidPatch repairs performed well under accelerated trafficking at all installations, exhibiting no more than 6 mm of rutting (less than 1⁄4 in.) after 1,000 passes of heavy truck loading. After 9 to 12 months of operational traffic and environmental exposure, both iHMA and RapidPatch repairs have performed well.

The Global Air Land Weather Exploitation Model (GALWEM) Acquisition System (GAS) is a software platform that serves to automate and simplify the procurement of numerical weather prediction model data from the 557th Weather Squadron. GAS allows for the download of meteorological and other environmental parameters from the GALWEM, an operational Numerical Weather Prediction capability operated by the 557th Weather Squadron for use by both Air Force and Army interests. GAS provides the ability to archive GALWEM data so that it may be used by the US Army Engineer Research and Development Center (ERDC) and other researchers. The report describes multiple methodologies for data access as well as suggestions for future work to improve computational efficiency and customer access.