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Full-Text Articles in Engineering

Determination Of The Optimal Parameters For Self-Healing Efficiency Of Encapsulated Bacteria In Concrete Simulated Subtropical Climate, Momen R. Mousa, Marwa Hassan, Gabriel Andres Arce Amador, Ricardo Hungria, Andrea Gavilanes, Omar Kamal Aug 2021

Determination Of The Optimal Parameters For Self-Healing Efficiency Of Encapsulated Bacteria In Concrete Simulated Subtropical Climate, Momen R. Mousa, Marwa Hassan, Gabriel Andres Arce Amador, Ricardo Hungria, Andrea Gavilanes, Omar Kamal

Publications

Concrete is a remarkable construction material. However, its low tensile strength makes it prone to cracking, which negatively affects its durability. To address this issue, bacterial concrete has been implemented as a self-healing alternative due to its capability to seal microcracks through microbial-induced calcium carbonate precipitation (MICCP). In this study, a bacterial strain (i.e, Bacillus Pseudiformus) was encapsulated through three different methods: encapsulation through hydrogel beads, vacuum impregnation on lightweight aggregates, and attachment to cellulose nanocrystals. Furthermore, three precursor types were used, magnesium acetate, calcium lactate, and sodium lactate were implemented. Compressive strength tests and flexural strength tests were performed …


Bridge Cracks Monitoring: Detection, Measurement, And Comparison Using Augmented Reality, Fernando Moreu, Kaveh Malek Aug 2021

Bridge Cracks Monitoring: Detection, Measurement, And Comparison Using Augmented Reality, Fernando Moreu, Kaveh Malek

Publications

Crack occurrence and propagation are among critical factors that affect the performance and lifespan of civil infrastructures such as bridges. Consequently, numerous crack detection and measurement methods have been proposed and developed in the recent decades in the areas of Structural Health Monitoring and non-destructive testing. Many novel technologies have emerged with the potential to overcome the limitations of the presented techniques of crack detection and characterization. Crack detection and characterization method used in this research lies in supplementing human visual inspection capabilities in a systematic manner through an appropriate level of automation. The Augmented Reality (AR) tool developed in …


Maintenance And Restriping Strategies For Pavement Markings On Asphalt Pavements In Louisiana, Momen R. Mousa, Marwa Hassan Aug 2021

Maintenance And Restriping Strategies For Pavement Markings On Asphalt Pavements In Louisiana, Momen R. Mousa, Marwa Hassan

Publications

In Louisiana, most districts restripe their roadways using waterborne paints every other year; this strategy is questionable in terms of efficiency and economy. Meanwhile, previous studies showed substantial variability in the paint service life throughout the United States ranging between 0.25 and 6.2 years. Shortcomings in modeling the retroreflectivity of waterborne paints appear to significantly contribute to these variations as several studies predicted these values using degradation curves with a coefficient of determination (R2) as low as 0.1. Therefore, the objective of this study was to (i) develop new cost-effective restriping strategies using 4-inch (15-mil thickness) and 6-inch (25-mil thickness) …


Residual Life And Reliability Assessment Of Underground Rc Sanitary Sewer Pipelines Under Uncertainty, Himan Hojat Jalali, Moein Ebrahimi Aug 2021

Residual Life And Reliability Assessment Of Underground Rc Sanitary Sewer Pipelines Under Uncertainty, Himan Hojat Jalali, Moein Ebrahimi

Publications

Prioritization of limited funding for pipelines maintenance is a major issue that concerns municipalities nationwide. Conducting a probabilistic assessment can provide a complete characterization of the performance of structural elements and systems along with optimizing the limited resources. The most widely used probabilistic performance indicator is reliability, a measure of the probability of failure corresponding to a particular limit state (e.g., ultimate strength or serviceability). Reliability methods can be used to identify which pipeline sections within a particular system require the most urgent inspection or repair. To this end, an automated data-driven framework for large diameter reinforced concrete pipes (RCPs) …


Development Of A Multi-Level Dynamic Model To Measure The Resilience Level Of Transportation Infrastructure Networks, Sharareh Kermanshachi, Jianling Li, Thahomina Jahan Nipa Aug 2021

Development Of A Multi-Level Dynamic Model To Measure The Resilience Level Of Transportation Infrastructure Networks, Sharareh Kermanshachi, Jianling Li, Thahomina Jahan Nipa

Publications

The recent increase in disasters is making the largest critical infrastructure system namely the transportation infrastructure system susceptible to unexpected damage. Discontinuation of services provided by transportation infrastructures will create significant societal, economic, and collateral damages. Therefore, this study aims to identify dimensions to measure the resilience of the transportation infrastructures. This study also aims to develop a model to measure the resilience of the transportation infrastructures resilience. To fulfill the aims of this study, a questionnaire was developed which was supported by a comprehensive literature review. 92 valid responses were received and analyzed qualitatively and quantitatively. Statistically significant variables …


Safety Of Vulnerable Road Users (Vru's) In Light-Rail Transit (Lrt) Environment, Samir Ahmed, Rifat Bulut Jul 2021

Safety Of Vulnerable Road Users (Vru's) In Light-Rail Transit (Lrt) Environment, Samir Ahmed, Rifat Bulut

Publications

Light-rail transit (LRT), which includes modern streetcars, trolleys, and heritage trolleys, is one of the fastest growing modes of public transportation in the United States. To reduce the cost and complexity of construction, most LRT systems have their tracks placed on city streets, in medians, or in separate at-grade rights-of-way with at-grade crossings. Operating light-rail vehicles (LRVs) along these alignments introduces new conflicts and increases the risk of collisions with vulnerable road users (VRUs) including pedestrians, bicyclists, and electric scooter riders. This study has two main objectives: (1) to review and evaluate the existing body of knowledge and the state …


Analysis, Modeling, And Simulation (Ams) Case Studies Of Connected And Automated Vehicle (Cav) Implementations Specific To The South Central Region, Christopher Melson, Jiaqi Ma May 2021

Analysis, Modeling, And Simulation (Ams) Case Studies Of Connected And Automated Vehicle (Cav) Implementations Specific To The South Central Region, Christopher Melson, Jiaqi Ma

Publications

Connected and automated vehicles (CAVs) offer potentially transformative and far-reaching impacts to the transportation system. However, realized benefits will be directly tied to how well agencies prepare for these technologies. This report documents efforts that support CAV preparatory actions in Louisiana and includes: (1) conducting a stakeholder survey to inform engagement activities to develop strategic partnerships in CAV deployment and (2) conducting crash analyses for deployment scenarios of CAV-based queue warning systems (QWSs).

An electronic survey was developed and disseminated to 273 Louisiana organizations. The purpose of the survey was to engage these organizations under the context of CAV planning …


Cross Domain Iw Threats To Sof Maritime Missions: Implications For U.S. Sof, Gary C. Kessler, Diane M. Zorri May 2021

Cross Domain Iw Threats To Sof Maritime Missions: Implications For U.S. Sof, Gary C. Kessler, Diane M. Zorri

Publications

As cyber vulnerabilities proliferate with the expansion of connected devices, wherein security is often forsaken for ease of use, Special Operations Forces (SOF) cannot escape the obvious, massive risk that they are assuming by incorporating emerging technologies into their toolkits. This is especially true in the maritime sector where SOF operates nearshore in littoral zones. As SOF—in support to the U.S. Navy— increasingly operate in these contested maritime environments, they will gradually encounter more hostile actors looking to exploit digital vulnerabilities. As such, this monograph comes at a perfect time as the world becomes more interconnected but also more vulnerable.