Graduation Semester and Year

2019

Language

English

Document Type

Thesis

Degree Name

Master of Science in Civil Engineering

Department

Civil Engineering

First Advisor

Xinbao Yu

Abstract

Bridge icing is a severe safety concern for travel during winter months in the United States. Ice on bridges form quicker than roads, as the bridge is exposed to wind on all its surfaces. The underlying problem of bridge icing is loss of friction between the vehicle wheel and the pavement surface due to slippery nature of ice. Hence, the solution is to increase the friction between the above-mentioned surfaces. The most commonly adopted solution is application of sand, salt or other granular materials on the roadway. However, due to corrosive nature of the salts, the durability of the infrastructure is affected. Hence, alternative pavement de-icing technologies are becoming popular, playing an important role in transportation safety and environmental protection. One of the sustainable bridge de-icing options is a ground source heat pump (Zhang, Yu, & Li, 2017; Li, Lei, Zhang, & Puppala, 2018). The theoretical principle of this technique is exploitation of relative constant temperature and heat storage capacity at around 10-30 feet underground and use of this heat storage capacity as a heat source for slab de-icing in winter (Bowers and Olgun, 2014; Li, et al., 2018). This heat source, coupled with hydronic loops embedded inside the bridge deck, acts as a de-icing system for the bridge decks. TxDOT is currently investigating the potential of using hydronic system in the highway bridge decks to counter the bridge icing problem in Dallas-Fort Worth (DFW) Area. Therefore, a numerical model needs to be developed and the local weather variables need to be simulated to evaluate the de-icing efficiency of the proposed hydronic system in Dallas-Fort Worth (DFW) Area. In the current study, an experimental bridge deck, along with the hydronic system attached to the bottom of the deck slab, was set up by the geothermal research group under the supervision of Dr. Xinbao Yu. The performance of the system was evaluated in actual weather conditions by monitoring the temperature of the installed thermocouples at different locations within the slab with respect to ambient temperature and wind speed. Based on the experimental design, a numerical model was developed in COMSOL and the model was validated by thermocouple data obtained from the experimental deck slab. With the validated numerical model, performance of the proposed system was evaluated by simulating the coldest days of last five years (2014-2018) and monitoring the slab temperature on the model. The effect of using insulated foam at the bottom of the bridge deck was also investigated. An analytical thermal resistance model was also developed to determine the consistency between the experimental, numerical and theoretical results obtained during the study. Based on the results obtained during the study, it can be concluded that the proposed hydronic system is adequate to prevent ice formation on bridge decks in DFW area.

Keywords

Externally heated bridge, Bridge de-icing, COMSOL modeling de-icing, Bridge de-icing efficiency, Geothermal bridge deck, Geothermal de-icing

Disciplines

Civil and Environmental Engineering | Civil Engineering | Engineering

Comments

Degree granted by The University of Texas at Arlington

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