Topic 1

Title: Development of a Model to Assess Costs of Opening a New or Closing an Existing Outpost or County Garage
State Job Number: 14637
Final Report, September 1998 (8,183 KB)
Executive Summary, (75 KB)

With the changes in urban development patterns and technological advancements, many times, it is necessary to open a new or close an existing outpost or a garage to maintain highway network in an optimum fiscal way. However, the decision to open or to eliminate facilities creates severe monetary and personnel implications and needs proper consideration of all cost elements.

 

Topic 2

Title: Evaluation of ODOT Roadway/Weather Sensor Systems for Snow & Ice Removal Operations
State Job Number: 14758
Final Report Part I, June 2003 (2,614 KB)
Executive Summary Part I, (411KB)

Final Report Part II, May 2003 (3,151 KB)

Executive Summary II, (560 KB)

Appendix Part II, (6,928 KB)

Final Report Part III, September 2003 (3,410 KB)

Final Report Part IV, November 2006 (7,420 KB)
Executive Summary Part IV, (66 KB)

Final Report Part V, October 2006 (26,847 KB)
Executive Summary Part V, (36 KB)

Appendices Part V, (1,867KB)

 

The Ohio Department of Transportation (ODOT) has initiated pretreatment as an integral part of a winter management strategy. Currently forty gallons per lane mile of 23% salt brine (NaCl) by weight is applied at a minimum frequency of two times per week when conditions warrant. In order for ODOT to develop the most effective plan for pretreatment, an in-situ study to provide data on decay of brine on trafficked pavement was needed. Objectives included a survey of other state DOT's pretreatment protocols, laboratory studies to discern brine concentrations that precluded ice formation, brine decay with traffic and time on several pavements, and correlation of laboratory and field data. Ten of the 28 state DOTs responding to the survey regarding pretreatment protocol applied NaCl two to 24 hours prior to a storm; two states used surface type, traffic volume, and air temperatures for decision making. The survey reinforced the need of laboratory and field studies. In the laboratory, release temperatures of the ice/surface bond at various brine concentrations were obtained utilizing conductivity and physical observation techniques. Laboratory tests with the field brine measurement instrumentation (SOBO-20 by Boschung Megatronic AG) provided correction factors for the field data on AC and PCC pavements. Sodium chloride brine was applied and measured in-situ in mass per area at five field sites (ATH-50 PCC, ATH-50 AC, DEL-23 PCC, DEL-23 AC, and ATH-33 AC) encompassing at least four sections at each site. Initial losses and decay due to time/traffic were obtained. Of the five test sites, AC (micro seal), AC (NOVA chip), and a transversely grooved PCC pavement provided statistically valid data to develop residual decay equations as a function of time/traffic. Field decay of brine was incorporated into laboratory brine/ice/ specimen bonding temperature findings to determine the effective ice prevention temperatures as a function of time/traffic for AC and PCC at standard application rates.

 

Topic 3

Title: Effectiveness of RWIS Bridge Temperature Simulators
State Job Number: 134216
Final Report, May 2007 (12,027 KB)
Executive Summary, (56 KB)

Appendices, (8,735 KB)

Bridge deck simulators (BDSs), 6 in (15 cm) concrete cubes with an embedded temperature probe, are intended as a cost-effective substitute for RWIS pavement sensors to represent conditions likely on bridge decks in an area near an RWIS station. In this study, the effectiveness of the BDSs to predict the temperature on nearby bridge decks was evaluated. Nine sites were selected by ODOT across the state of Ohio (six in northeastern region and three in southwestern region) which were instrumented with BDSs and Nu Metrics pavement sensors on the bridge deck and (with one exception) on the road surface off the bridge. The use of BDSs appears to be unique to Ohio. A survey in the state of Ohio indicated little use was being made of BDS information. RWIS temperature data collected at five minute intervals during winter season 2004-2005 were analyzed and the unusable data were weeded out by removing redundant entries, blank or incomplete entries, extreme temperature readings, and entries where sensor data were not updated. Correlation analysis was performed on the “cleaned” data from the nine sites for the air and BDS temperatures versus bridge deck and road temperatures, and also for air versus BDS temperatures. Separate correlations were made with all-day data and with nighttime data free of solar radiation effects. For both all-day and nighttime data, the BDS was found to better correlate with bridge deck and road temperatures than was the air temperature. The nighttime data were then further analyzed to determine 90%, 95%, 99% prediction limits for the prediction of bridge deck and road temperatures based on the BDS and air temperature values. Again, the prediction limits for bridge and road temperatures using the BDS were generally tighter than when using air temperature. Finite element analyses (FEA) were performed for the nine sites using ALGOR V18 software to investigate the temperature behavior of the bridge deck and the BDS for the air temperature profiles reflecting extreme positive and negative temperature gradients recorded at each site. The FEA modeling provided information about how the BDS and the bridge deck temperature change as a function of the air temperature and time. Larger concrete cube sizes, up to 24 in (61 cm) on a side, were investigated with FEA in an exploratory manner. The 24 in (61 cm) cube almost exactly matched the simulated bridge deck temperature profiles under a variety of air temperature loads. The FEA temperature profiles showed that the existing BDS does not always closely represent the true temperature behavior of the bridge deck, but that a concrete cube 4 times larger on a side would compare much better. Yearly training of maintenance personnel in the use of the BDS and RWIS is recommended.