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Submissions from 2021

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Case Studies of Problematic Expansive Soils: Characterization Challenges, Innovative Stabilization Designs, and Novel Monitoring Methods, Anand J. Puppala
Streaming video available

Abstract:

This presentation describes key research works on expansive soils, the methods employed to characterize them, and fallacies in the current characterization of expansive soils. Novel swell characterization models that account for hydro, chemical, and mechanical behaviors of soils are introduced and used in various case studies to improve expansive soil stabilization practices. An innovative design method for successful stabilization of expansive soil is introduced in one case study which incorporated both basic clay mineralogy and unsaturated soil behaviors, as well as performance-based durability studies. Sulfate soil stabilization works on medium-to-high sulfate soils are presented in another case study. The last case study involving steep earthen embankment built with expansive clayey soils and experiencing recurring surficial slope failures and maintenance issues is presented along with forensic studies explaining the causes of slope failures. All case studies reveal the need for understanding of soil chemistry, including clay mineralogy and sulfate screening studies, to improve the current field stabilization and infrastructure design on expansive soils. The last section of the talk focuses on recent innovations for better health monitoring and management of civil infrastructure built on expansive soils using unmanned aerial vehicle (UAV) platforms and visualization tools, which will be valuable in validating the application of new materials in infrastructure design and construction processes as well as for health monitoring and asset management practices.

Resilience-Informed Guidance through Modeling and Interdisciplinary Field Studies, John W. van de Lindt
Streaming video available

Abstract:

The study of community resilience requires modeling of each sector across a community, but the sectors must interact, often representing contributions from different scientific disciplines. This type of complex modeling requires the analyst to not only have an understanding of disciplines outside of engineering but to actively work and engage with key experts in sociology/planning and economics. This presentation will begin with an overview of the Center for Risk-Based Community Resilience Planning’s approach to merge engineering, social science/planning, and economics to form the Interdependent Networked Community Resilience Modeling Environment (IN-CORE). This includes learning from an interdisciplinary longitudinal field study beginning in 2016 to present for flooding in Lumberton, NC, including challenges posed by a second hurricane and the pandemic on data collection and interpretation. The presentation will close with an illustrative example application of a community planning for tornado hazard and an example of resilience-informed policy guidance.

Submissions from 2019

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Diffusion and Uniformity of Recycled Asphalt in Pavements, Baoshan Huang

Abstract:

Asphalt pavements covers over 93 percent of the paved roads in the United States. The use of recycled asphalt into pavement maintenance and construction has been a common practice. However the lack of understanding of the interaction between recycled and virgin asphalt poses a change on the efficient use of recycled asphalt, and often causes pavement premature failures. The present study addressed some fundamental aspects associated with the beneficial use of recycled asphalt into asphalt paving mixtures: 1) how much recycled asphalt can be mobilized into a uniform asphalt coating in the mixture? and 2) will the mobilized old asphalt co-mingle with virgin asphalt to form a homogeneous material? Analytical chemical procedure and fluorescence microscopy (FM), and molecular dynamics simulation have been utilized for the analyses. The results have provided better understandings on the homogenization process between the recycled and virgin asphalt; thus provide better guidance to efficient use of recycled asphalt pavements.