News about Science, Technology and Engineering at Iowa State University
Highways are expensive. Each mile of concrete highway in Iowa costs about $1 million. Paul Spry, an Iowa State University professor of geological and atmospheric sciences, is working on methods that will help extend the life of concrete highways and allow taxpayers to get the most out of their investment. Spry, along with Robert Cody, associate professor emeritus of geological and atmospheric sciences, has been studying de-icing effects on Iowa concrete highways for the past decade. They recently received $142,000 from the Iowa Department of Transportation for a new study.
During winter months, many Midwest states apply de-icing chemicals on roadways to keep the roads safe. The de-icing chemicals also accelerate the aging process of the roads, with noticeable deterioration happening in five years on a road with a designed lifetime of 40 years. Spry and Cody's studies have found that certain minerals were growing and filling spaces within the concrete and causing cracking.
"One of the minerals that had a major effect was ettringite," Spry said. "Some of it grew during a delayed reaction and caused cracking in the concrete." The researchers, working with Anita Cody, also of geological and atmospheric sciences, have tested inhibitors that limited the growth of ettringite in concrete. "We figured if we could limit the growth of ettringite then we could reduce the deterioration of the concrete," Spry added.
The new study will continue to look at the reduction of concrete deterioration by ettringite. Spry and Cody will evaluate inhibitor effectiveness using crystal growth techniques. Long-term growth of ettringite will be simulated and core road samples will be exposed to typical Iowa hot and cold temperatures. They will also increase the concentration of the inhibitor in the concrete to speed up the rate of the reaction.
"We are one of the few geological groups that does this type of work," Spry said. "We understand the materials involved and that's one of the keys to the success we have had with this project." For more information, contact Spry, (515) 294-1837, or Dave Gieseke, LAS Public Relations, (515) 294-7742.
Iowa State helps other states locate crashes
Iowa State University scientists are helping the New York State Police and the Georgia Department of Transportation collect more accurate accident information using an incident location tool. The tool was designed by Dan Gieseman and Reg Souleyrette, staff members of Iowa State's Center for Transportation Research and Education (CTRE). It was originally developed for the Iowa Department of Transportation. The tool is one part of a larger data collection and management technology system that approximately 200 Iowa agencies, including the Iowa State Patrol and the Office of Motor Vehicle Enforcement, are using to share safety information.
Now Gieseman, a transportation systems analyst, is reprogramming and generalizing the tool so that it can more easily work with other states' data requirements. The incident location tool uses geographic information systems (GIS) software to provide users with a map-based computer screen. Users can locate car crashes and other incidents precisely on a digital map. The information is stored locally for later download. For more information, contact Dan Gieseman, (515) 296-0796, or Michele Regenold, CTRE, (515) 296-0835.
"Lite" done right
Better performance for less hassle -- that's the advantage a new message-passing library, MP_Lite, developed at the U.S. Department of Energy's Ames Laboratory at Iowa State University. The library can extract optimum performance from workstation and personal computer clusters, as well as from massively parallel computers. It supports and enhances the basic capabilities that most software programs require to communicate between computers.
MP_Lite is a "slimmed-down," user-friendly version of the message-passing interface (MPI) standard, a widely used model that standardizes the syntax and functionality for message-passing programs. Parallel libraries that offer the full MPI standard ease programming problems by reducing the need to repeat work, such as defining consistent data structures, data layouts and methods that implement key algorithms. Although it can be scaled up easily, MP_Lite offers only the core MPI functions, implementing them in the most efficient manner to provide all the performance without all the extras.
"Our goal with MP_Lite is to illustrate how to get better performance in a portable and user-friendly manner, and to understand where any inefficiencies in the MPI standard may be coming from," said Dave Turner, an Ames Laboratory assistant scientist and the principal investigator on the project. "MP_Lite is ideal for performing message-passing research that may eventually be used to improve full MPI implementations and possibly influence the MPI standard." MP_Lite is free and can be downloaded from:
. For more information, contact Turner, (515) 294-1307, or Saren Johnston, Ames Lab Public Affairs, (515) 294-3474.
Ames, Iowa 50011, (515) 294-4111
Published by: University Relations,
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