Development of GDOT Ultra-High Performance Concrete for Bridge Deck Closure Pours

PI#0015961The use of precast prestressed girders with composite precast deck panels along with the use of precast prestressed deck bulb-T girders provide for more economical bridges because of their ability to utilize accelerated bridge construction techniques. The use of concrete deck panels and deck bulb-T systems require the use of closure pours between the units. Ductal\u2122, a proprietary ultra-high performance concrete (UHPC), has been shown to provide an outstanding link between deck segments for closure pours as narrow as 6-in, but Ductal is expensive. This research develops a concrete based on locally available materials (GDOT-UHPC), which has a direct tensile strength greater than 750 psi and ductility and toughness under tensile loads such that the concrete can develop the tensile yield stress of #5 (\u215d-in. diameter) reinforcing bars within a 5-in. embedment length. Minimizing the width of the closure between deck and bulb-T units provides further economies by greatly simplifying formwork and eliminating shoring. Testing assured not only the short development length of reinforcement but also ultimate strength capacity of transverse and longitudinal closure pours. Further, best practices for formwork, closure design, UHPC mixing and placement, and quality assessment are considered

Safety and Illumination of Rural and Suburban Roundabouts (Phase II)

RP19-11This project focused on establishing the relationship between the presence/absence or levels of illumination and other geometric and traffic characteristics on nighttime safety at rural and suburban roundabouts. Eighty roundabouts from thirty-seven counties across Georgia were selected to provide a wide range of conditions in terms of illumination layout, illumination levels, number of legs, number of circulating lanes, daily entering volumes, approach speeds, etc. for field measurements of illumination levels. Urban roundabouts with significant pedestrian activity were excluded. Field data collection at each site included both direct measurements of illumination levels as well as a civil site survey to verify the geometric characteristics of the roundabout and were conducted by measurement teams from Georgia Institute of Technology and Georgia Southern University. The resulting data were processed, joined, and aggregated to the individual site level and used to establish statistical relationships between observed nighttime crash rates, severity, and crash types (e.g., single vs. multiple vehicles, impaired drivers, etc.) and underlying geometric factors and measured illuminance levels. The variation in observed crash rates were modeled against known parameters of the roundabouts to develop a predictive model as to how single vehicle nighttime crash rates were impacted by illumination and other factors. As expected, multiple vehicle crashes showed no statistically significant dependence on illumination levels as the vehicles themselves, through their head- and taillights, are important contributors to nighttime visibility at the roundabout. This was not the case for single vehicle crashes. Single vehicle crashes were shown to increase for 3-leg roundabouts for illumination values less than 5 lux. No such trend was observed in either 4 or 5-leg roundabouts and these sites showed no statistically significant variation in nighttime single vehicle crash rates at any level of illumination. An overarching conclusion of the study is that there was no observed evidence of illumination values exceeding 5 lux resulting in a statistically significant reduction in nighttime crash rates for rural and suburban roundabouts. These results suggest that for rural and suburban roundabouts with no significant pedestrian volumes, illumination values significantly lower than current standards may still prove effective as a safety treatment and that, in the absence of a need to protect pedestrians or cyclists at nighttime at a particular location, a reduction in lighting levels or the use of passive retroreflective safety treatments may be a cost-effective treatment

Modeling Driver Physiological State Using EEG Under Auditory Real-time Travel Information Provision

Poster Presented on March 5, 2019 at the 105th Purdue Road School Transportation Conference and Expo, Purdue University, West LafayetteModeling driver physiological state using EEG under auditory real-time travel information rovision poster presented on March 5, 2019 at the 105th Purdue Road School Transportation Conference and Expo, Purdue University, West Lafayette

Bio-logger Ethogram Benchmark: A benchmark for computational analysis of animal behavior, using animal-borne tags

This repository contains the datasets presented in our forthcoming work: B. Hoffman, M. Cusimano, V. Baglione, D. Canestrari, D. Chevallier, D. DeSantis, L. Jeantet, M. Ladds, T. Maekawa, V. Mata-Silva, V. Moreno-González, A. Pagano, E. Trapote, O. Vainio, A. Vehkaoja, K. Yoda, K. Zacarian, A. Friedlaender, and C. Rutz, "A benchmark for computational analysis of animal behavior, using animal-borne tags," 2023. It also contains the experiment results which are reported in the paper. Standardized code to implement, train, and evaluate models can be found at https://github.com/earthspecies/BEBE/. Please note the licenses in each dataset folder. Zip folders beginning with "formatted": These are the datasets we used to run the experiments reported in the benchmark paper. Zip folders beginning with "raw": These are the unprocessed datasets used in BEBE. Code to process these raw datasets into the formatted ones used by BEBE can be found at https://github.com/earthspecies/BEBE-datasets/. Zip folders beginning with "experiments": Results of the cross-validation experiments reported in the paper, as well as hyperparameter optimization. Confusion matrices for all experiments can also be found here