1 Oct 2020

Evaluation of Solid-Polymer-Modified Asphalt Mixtures Phase 1: Construction and Performance Testing of Field Pavement Sections

ABSTRACT:  The durability of flexible pavements in cold regions is a challenge due to the impact of environmental conditions and seasonal variations. Other studies have investigated several modifiers as potential solutions to ad-dress cold climate durability of asphalt mixtures. Among these modifiers, polymer modification has shown promise. This study investigated the addition of solid polymer to asphalt mixtures to improve the performance and structural capacity of the material. Four test sections were constructed with different solid-polymer dosage rates: unmodified control, 2.5% polymer, 5% polymer, and 7.5% polymer by weight of binder. Falling weight deflectometer (FWD) testing was con-ducted at each test section to evaluate the structural capacity and to identify the performance benefits of the solid-polymer-modified mixtures. This study conducted a comprehensive analysis, including maximum pavement deflection, deflection bowl parameters, backcalculation analysis, structural number, and impulse stiffness modulus. The field investigation results revealed structural benefits in test sections with the solid-polymer-modified mixture (7%–30% increase in stiffness, depending on the dosage rate). Results suggest that solid-polymer modification could be useful in improving the stiffness of asphalt pavements without compromising durability. Therefore, further investigations should evaluate the durability of the solid-polymer-modified asphalt pavements under different environmental conditions.

1 Oct 2020

Mindbreeze InSpire Search Appliance Implementation and Lessons Learned

Abstract: The U.S. Army Engineer Research and Development Center (ERDC) Knowledge Management relies on enterprise search technology to index and search ERDC’s accumulation of knowledge stored on various web connected systems. In 2016, Google announced the discontinuation of their search product, the Google Search Appliance (GSA), at the end of March 2019. After conducting extensive market research and identifying a suitable replacement that met all ERDC requirements, a competing product called Mindbreeze InSpire was chosen. This product provides a simple-to-use interface that facilitates quick location and retrieval of ERDC knowledge located on ERDC’s internal and extranet websites, and is designed for simple and intuitive installation and configuration. This document investigates and details the acquisition, installation, and configuration of the Mindbreeze InSpire enterprise search appliance, and the lessons learned throughout the entire implementation process.

1 Oct 2020

USACE BIM Object Library user guide: Release 1.0

Abstract: The U.S. Army Corps of Engineers (USACE) is in need of a centralized repository of standardized Building Information Modeling (BIM) Objects. This repository is needed to serve as the BIM Object Library to be utilized by architects and engineers on architectural and engineering federal design projects. The U.S. has more than 109,000 registered architects and 820,000 licensed professional engineers that could potentially have access to this BIM Object Library. The CAD/BIM Technology Center has currently harvested more than 8,500 BIM Objects from USACE districts. It is expected that the USACE BIM Object Library will grow to more than 35,000 BIM Objects based on the existing content being managed by each individual USACE district. The CAD/BIM Technology Center’s research shows that the content management system solution needs to provide BIM objects that contain all the information required to design, find, locate, specify, interrogate, and analyze the represented product. The study also shows the solution should provide an intuitive interface which allows users to easily retrieve the BIM objects that meet a set of user defined criteria. Furthermore, the solution should verify the BIM Objects selected for inclusion into the USACE BIM Object Library comply with the advanced modeling object standard. Finally, the study shows that the solution should be capable of efficiently and effectively managing and querying at least 5 million parameters and associated values.

1 Oct 2020

Electronic Railroad Inspection Database System for Military Facilities

Abstract: The U.S. Army Engineer Research and Development Center (ERDC) executes inspection programs as part of the U.S. Army Transportation Infrastructure Inspection Program (ATIIP). These inspections, monitoring, and assessment programs include airfields, bridges, dams, railroads, waterfront facilities, and ranges. To date, the process for these inspection programs has been manually intensive, time consuming, and difficult to scale. The ERDC is bringing digital business and spatial data collection methods to its inspection program for the military’s railroad infrastructure. By combining GPS and GIS technologies into a mobile data collection solution, added efficiency and data quality have been brought to the field inspection workflow. This modernization effort also results in streamlined data processing and reporting. These improved processes will lead to higher quality data, better analysis of the new richer data content, and better decisions made by the end-users and stakeholders.

1 Oct 2020

Framework Geology of Cape Shoalwater and Northwest Willapa Bay, Washington: Assessing Potential Geologic Impacts on Recent Shoreline Change

Abstract: The shoreline along Cape Shoalwater and northwest Willapa Bay has experienced the highest rates of erosion along the entire Pacific Coast of the United States, due in part to rapid northward migration of the navigation channel. Recently, channel migration and shoreline erosion in this region have slowed, but the cause of this relative stabilization, and thus the longevity of these new patterns, is unknown. Given the complex neotectonics and geologic framework of the southern coast of Washington, it is possible that underlying, erosion-resistant geologic units have become exposed along the channel and/or in the nearshore, and are acting to reduce or halt channel migration and/or shoreline erosion. Conversely, the apparent reduction may be due to subtle, short-term changes in regional hydrodynamics and/or sediment transport, and thus future rates of channel migration and/or shoreline erosion might increase back to historical rates. The purpose of this special report is to detail the geologic and neotectonic framework of the northern Willapa Bay region, and determine how the underlying framework geology might be impacting channel stability and adjacent shoreline erosion rates. Suggested research questions to quantify potential geologic control are also presented, including the potential benefits of the research to the district.

1 Oct 2020

Documenting Engineering with Nature® Implementation within the US Army Corps of Engineers Baltimore District – Completed Projects and Opportunities for Chronosequence Analysis

Purpose:  The following documents the beneficial use of dredged materials in a subset of shallow draft navigation projects conducted by the US Army Corps of Engineers (USACE) Baltimore District between 1904 and 2016. The available data demonstrates (1) the expansion of beneficial uses of dredged materials over time incorporating Engineering With Nature® (EWN) approaches and (2) provides baseline information supporting chronosequence studies of habitat restoration/creation trajectories designed to evaluate project success.

1 Oct 2020

Laboratory Evaluation of Aquablok™ Erosion Resistance: Implications for Geotechnical Applications

Abstract: AquaBlok™ (AB) is a commercial product traditionally used as an alternative material for contaminated sediment capping applications. Previous studies of AB capping performance have reported enhanced stabilization through increased erosion resistance. Subsequently, AB has been considered for use as an alternative levee repair material due to its cohesive properties. Through a series of laboratory experiments, this study investigated the erosion behavior of new AquaBlok formulations (10%, 20%, and 30% clay by weight) under increased shear stresses previously unachievable in the previous tests. The new AquaBlok formulations were tested in non-compacted and compacted states to simulate the physical properties in capping and levee repair applications. In the non-compacted state, excess hydration of the clay matrix extended approximately 5 cm below the bed surface, which greatly reduced erosion resistance and was independent of clay percentage. Below this horizon, critical shear stress increased, and erosion rates decreased, with clay percentage, respectively. However, this does not consider a continuous change in hydration state when exposed to free water. In the compacted state, erosion rates were greatly arrested, with measureable erosion only possible under the maximum applied shear stress (24 Pa). The results are discussed in the context of capping and levee applications.

1 Oct 2020

Understanding the Disease Vector Operational Environment by Predicting Presence of Anopheles Mosquito Breeding Sites Using Maximum Entropy Modeling and the Maxent Software Platform

Purpose: This technical note (TN) describes research using the maximum entropy model to predict the presence of breeding sites for mosquitos of the genus Anopheles throughout the Korean peninsula. This methodology is also applicable to many other types of ecological niche modeling problems where analysts only have access to data related to the location a species has been found. The purpose of this study is to help address the need for new and innovative methods that promote military readiness through better understanding of vector-borne disease threats in familiar and unfamiliar operational environments. These methods can be used to provide military planners with valuable information to support their operations, particularly when operations expand into areas lacking direct disease vector surveillance. Disease vector risk information is vital for force readiness, because historically, soldiers are more likely to be unable to perform warfighting due to disease and non-combat injuries than as a direct result of combat (U.S. Department of the Army 2015).

29 Sep 2020

A First Examination of the Interaction between Alternaria alternantherae and Agasicles hygrophila on Alternanthera philoxeroides

PURPOSE: The use of an alligatorweed (Alternanthera philoxeroides) insect biological control agent, alligatorweed flea beetle (Agasicles hygrophila Selman and Vogt), and the leaf spot plant pathogen, alligatorweed leaf pathogen (Alternaria alternantherae Holcomb and Antonopoulis), may provide enhanced control of alligatorweed infestations if competitive interactions between agents are minimal and damage to host plants are synergistic. However, to assess suitability of co-use of these two agents, it is necessary to first identify whether introduction of one may impact performance of the other. This technical note details a first examination of competitive interactions between A. hygrophila and A. alternantherae under varied temperature and host nutritional conditions. Presented are the results of laboratory experimentation and recommendations for future research.

29 Sep 2020

Using Unmanned Aircraft System (UAS) and Satellite Imagery to Map Aquatic and Terrestrial Vegetation

Purpose: The purpose of this study is to demonstrate the application potential of using unmanned aerial systems (UAS) combined with a time series of moderately high-resolution satellite imagery for mapping ecological restoration progress and resulting land cover changes. This technical note addresses a project under the US Army Corps of Engineers Ecosystem Management and Restoration Research Project (EMRRP) focusing on image acquisition and assessment, digital image processing techniques, analytical methodology, geospatial product development, and documentation of best practice for future data acquisition and analysis in support of ecological management efforts.