Journal of Cold Regions Engineering

This study was undertaken to identify test procedures capable of reliably assessing concrete aggregate freeze-thaw durability and establish appropriate acceptance criteria for the same. Highway condition surveys were performed to document the field freeze-thaw performance of selected aggregate sources representing a range of frost resistance. Cores were obtained for laboratory testing and evaluation, and samples of the original aggregate sources were obtained for use in performing environmental simulation tests [i.e., variations of ASTM C 666 and the Virginia Polytechnic Institute (VPI) single-cycle slow-freeze test] and correlative tests (e.g., absorption capacity, Iowa pore index test, X-ray diffraction and fluorescence analysis, and hydraulic fracture test). Petrographic examination was used to correlate aggregate geological and engineering properties with the results of environmental and correlative tests. A suite of tests was developed for more accurately assessing the probable field performance of any given aggregate as a function of its original geological origin and probable environmental exposure. Petrographic examination is used first to identify aggregate composition and provide a basis for selecting subsequent durability tests, which may include the hydraulic fracture test, VPI single-cycle slow-freeze test, and ASTM C 666 Procedure B (modified to use salt-treated aggregates).

Two monopod bucket foundation platforms were installed in 1997 in a shallow water area of the Bohai Sea, where the drifting ice is a dominant factor in platform design. This paper describes the design, installation, and 1-year operation of the platforms.

This study compares snow event and equivalent nonsnow interstate vehicular crash rates and investigates weather-related elements that may contribute to crash occurrence during snow events. Vehicular crashes reported in the state of Iowa are examined on seven different sections of the interstate highway system during the 1995/1996, 1996/1997, and part of the 1997/1998 winter seasons. A geographic information system was utilized to combine crash records with weather and traffic count data to obtain the data set analyzed in this study. A significant increase was observed when winter snow event crash rates on the seven interstate highway sections were compared to crash rates on those same sections during equivalent nonsnow conditions. Crash, weather, and traffic data were further analyzed to identify snow event elements that play important roles in crash occurrence on interstate highways. The results of a Poisson model for crash frequency indicated that snow event duration, snowfall intensity, and average wind speed during snow events are important contributory elements. Additionally, traffic volume during snow events was also found to be a significant factor in crash occurrence.

Tunnels have long been a part of specialized facilities found in Greenland and Antarctica. The low temperatures, severe windchill, drifting snow, and prolonged darkness these facilities experience necessitates the use of protective passageways for personnel and utilities. Several attempts have been made to develop subsurface tunneling systems, but technological challenges have limited these systems' effectiveness. In 1996, the U.S. Army Cold Regions Research and Engineering Laboratory deployed a subsurface tunneling system at the Amundsen-Scott South Pole Station for the purpose of excavating a utilidor. This system successfully machined a 125-m-long tunnel in the highly compacted firn adjacent to the station. At a maximum depth of 16 m, the tunnel currently provides a controlled environment for the station's wastewater outfall line. In 2001, a 600-m tunnel was completed. This technical note describes the tunneling system, its use, and lessons learned.