Michelle Akin

Exploring the Interactions of Chloride Deicer Solutions with Nanomodified and Micromodified Asphalt Mixtures Using Artificial Neural Networks

The objectives of this research are to modify an asphalt mixture with two materials—nanoclay and carbon microfiber—and to investigate the interactions of chloride deicer solutions with nano- and/or micromodified and unmodified asphalt mixtures in terms of indirect tensile strength (ITS) and fracture energy. Artificial neural networks (ANNs) were used in this study to establish predictive models and quantify the complex cause-and-effect relationships between the nano- or micromodification and conditioning of asphalt mixtures and the resulting mechanical properties. Four influential variables (nanoclay content, microfiber content, deicer type, and deicer dilution ratio) were collectively examined to predict the ITS and fracture energy of asphalt mixtures, and a back-propagation neural network of three layers with seven or nine hidden nodes was employed respectively. The established ANN models were then successfully used for numerical in- vestigations on the parameters affecting the asphalt properties. The addition of polysiloxane-modified montmorillonite and/or carbon micro- fiber (both at less than 2% by weight of asphalt binder) can enhance the tensile strength fracture energy of asphalt concrete mixtures and reduce their moisture susceptibility and cracking risk, and such benefits are especially significant when the asphalt concrete is conditioned in water or chloride-based deicer solutions. This evaluation makes it possible to design asphalt mixtures for a desired level of ITS or fracture energy in the absence or presence of common chloride-based deicer solutions. DOI: 10.1061/(ASCE)MT.1943-5533.0000452.

Development of Standard Laboratory Testing Procedures to Evaluate the Performance of Deicers

This work aims at identifying and developing standard laboratory testing protocols that can be used to evaluate the performance of deicing chemicals, additives, and mixtures of these used on roadways and other transportation facilities. Several test methods were evaluated for the purpose of developing a promising test protocol, including a differential scanning calorimetry (DSC) thermogram test for liquid deicers, modified Strategic Highway Research Program (SHRP) ice melting test for solid and liquid deicers, modified SHRP ice penetration test for solid and liquid deicers, and a modified ice undercutting test developed by Minnesota Department of Transportation (DOT) for solid and liquid deicers. These tests shed light on the complexity and challenges in evaluating various deicers, especially the poor reliability inherent in conventional test methods. The DSC-based method was demonstrated to be very reproducible for each deicer at a given dilution ratio and cooling/heating rate, and thus may serve as a “fingerprint” tool for quality assurance of deicers. The DSC data also showed strong correlation with the modified SHRP ice melting test data, which holds the promise of establishing the DSC-based method for evaluating the performance of liquid deicers (both in terms of characteristic temperature and ice melting capacity). The modified SHRP ice melting test used in this study incorporates a control substance for reference and various indicators to determine acceptability of the data, as discussed in the paper.

Evaluating Snow and Ice Control Chemicals for Environmentally Sustainable Highway Maintenance Operations

AbstractThe use of chemicals and abrasives for highway winter maintenance operations is an essential strategy for ensuring a reasonably high level of service, yet the performance of such materials has to be balanced with their potential negative impacts on motor vehicles, transportation infrastructure, and the natural environment. In this context, this work presents a comprehensive and quantitative evaluation of snow and ice control chemicals currently used by various Idaho Transportation Department districts for highway maintenance operations, including rock salts (mainly solid sodium chloride), IceSlicer products (solid sodium chloride with trace amounts of other chlorides), and salt brines. The analysis has been enabled by the utilization of existing lab and field test data along with reasonable assumptions, in the effort to identify environmentally sustainable materials for winter highway operations. Despite its caveats, this case study is the first attempt to incorporate the most up-to-date informati...

Holistic Approach to Decision Making in the Formulation and Selection of Anti-Icing Products

AbstractTo effectively fight snow storms in the challenging funding environment, many maintenance agencies in North America have started to produce their own anti-icing liquids, instead of procuring commercial anti-icers. This work demonstrates a systematic approach to collaborative, data-driven, and multicriteria decision making by conducting a set of laboratory tests to assess twenty blended chloride-based anti-icing formulations. The laboratory data were then used to establish predictive models correlating the multiple design parameters with the anti-icer performance and effects or with an anti-icer composite index. The authors used artificial neural networks for modeling and examined anti-icer performance (characteristic temperature and ice-melting capacity at 30 and 15°F (-1.1 and −9.4°C), respectively) and effects (splitting tensile strength of concrete after ten freeze-thaw cycles and corrosivity to mild steel) as a function of the formulation design. The anti-icer composite index was calculated fo...

Cost-Effective and Sustainable Road Slope Stabilization and Erosion Control

In the United States it is estimated that 75% of all roads are low-volume roads maintained by some 35,000 local agencies. Low-volume roads often omit surface slope protection, and this can lead to slope failure, erosion, and maintenance, safety, and ecological issues. This report presents information on cost-effective and sustainable road slope stabilization techniques, with a focus on shallow or near-surface slope stabilization and related erosion control methods used on low-volume roads. To fully address this topic, planning and site investigation are discussed, as well as erosion control techniques, soil bioengineering and biotechnical techniques, mechanical stabilization, and earthwork techniques. Information presented in this report was obtained through an extensive literature review, and from survey and interview responses. From the survey responses, 30 individuals were interviewed based on the information they made available in the survey. A total of 25 interviews were conducted over the phone, and in two cases written responses were received.

Highway Winter Maintenance Operations at Extremely Cold Temperatures

Winter maintenance operations are crucial for achieving a reasonable level of motorist safety and public mobility on highways in cold regions. Such activities become essential when a storm with extremely cold temperatures hits the area, either as a result of normal fluctuations or as a result of climate change. Once the pavement temperature drops below 10°F, the traditional tools (e.g., granular salt) become ineffective. To achieve a drivable pavement friction condition, excessive amount of plowing, chemicals, and/or abrasives are often used, which leads to substantial cost increases and environmental concerns. The most severe 20 percent of the storms can cost 80 percent of an agencys annual budget for winter maintenance. In this context, it is necessary to examine the best practices of highway winter maintenance operations with a renewed perspective so as to target these extreme storms. This work presents a synthesis of relevant information in the published domain with a focus on the traditional and innovative strategies potentially useful for highway agencies to fight extremely cold storms. This information can be valuable in the context of climate change, as certain areas may experience unusually cold snow or ice storms and face devastating consequences if unprepared for such scenarios.