Evaluation of Technologies for Nondestructively Determining Concrete Pavement Thickness

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.

The US Army Engineer Research and Development Center (ERDC) and the 20th Engineer Brigade, 27th Engineer Battalion, executed the Joint Airfield Damage Repair Symposium from 5 to 14 June 2023. The event was a training experience for personnel executing pavement-repair tasks and a planning and coordination exercise for senior military and civilian leaders developing technologies and plans for airfield damage repair (ADR). The participants included 14 trainers, 8 staff members, 48 observers, and 145 trainees from the US Army, Air Force, Navy, and Marines. The Military Occupational Specialty of most Army trainees was 12N, Horizontal Construction Engineer. The symposium also included a workshop attended by more than 20 organizations representing all branches of the US Military. Breakout sessions were used to develop strategies to address gaps in ADR materials, training, and doctrine. At the end of the symposium, the 27th Engineer Battalion identified needs for an updated joint doctrine detailing the capabilities residing within each service branch and defining their roles and responsibilities, equipment up-grades based on commercially available products that would enhance efficiency for ADR missions, positioning ADR materials in strategic locations to reduce the logistical burden of delivery, and lighter, more expeditionary ADR kits across each service.

: 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.

: In fiscal year 1993 (FY93), Congress appropriated $18 million to advance the use of phosphoric acid fuel cell (PAFC) power plants at Department of Defense (DOD) installations. An additional $18.75 million was appropriated in FY94 to expand the program. The Army, Air Force, and Navy/Marine Corps each received $6 million for the purchase, installation, and operation of the fuel cell power plants in EY93, and $6.25 million in EY94. By November 1997, DOD had installed 30 PAFC power plants throughout the continental United States and Alaska. The program has successfully demonstrated the capability of the PAFC technology by generating more than 101,977 Mwh of electricity through September 2000. The U.S. Army Construction Engineering Research Laboratory (CERL), a part of the U.S. Army Engineer Research and Development Center (ERDC), managed this program. CERL's activities included developing turnkey PAFC packages, devising site selection criteria, screening DOD candidate installation sites using selection criteria, evaluating viable applications at each candidate site, coordinating fuel cell site designs, overseeing installation and acceptance of the power plants, and monitoring and repofting the performance of the fleet.

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.

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.

This paper describes how the U.S. Army Engineer Research and Development Center (ERDC) initiated a new military research effort in 2001 known as the Joint Rapid Airfield Construction (JRAC) program. The JRAC program involves over twenty principal researchers from three ERDC laboratories, over thirty integrated research projects, scheduled research funds in excess of 20 million dollars, and two major field demonstrations during the seven-year research plan. The primary objective of this research program is to develop methodologies and materials for rapidly upgrading existing or constructing new contingency airfields with the lowest logistical footprint possible. The JRAC program is designed to meet this objective by; (1) integrating advanced terrain analysis technologies and performance prediction modeling to optimize contingency airfield site selection; (2) utilizing emerging commercial soil stabilization technologies to rapidly provide contingency airfield surfaces capable of sustaining mission operations; and (3) exploiting new construction technologies to enhance airfield construction productivity. It provides summaries of the background, current research efforts, and projected goals of the JRAC program. Discussions of spin-off' technologies useful to civil airports and other construction industries are also presented. Since the JRAC program seeks to exploit new and emerging technologies within the private sector, it is hoped that this paper will generate critical exchanges of information and perhaps foster important industry and government partnerships in the near future.

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.