U.S. Department of Transportation
Federal Highway Administration
1200 New Jersey Avenue, SE
Washington, DC 20590
|Accelerating Infrastructure Innovations|
Publication Number: FHWA-SA-97-028
Date: October 1997
Alkali-silica reactivity (ASR), which occurs beneath the surface of portland cement concrete bridges and pavements, is difficult to detect. Often, the first indication of the problem comes after the damage has been done, when the concrete has begun to crack and spall.
Engineers, researchers, and others trying to keep up with new information and products from the long-term pavement performance (LTPP) program can now turn to Tech Briefs, a new series of summaries of recent LTPP reports. Each brief provides a concise summary of the findings of a recent research project; outlines the impact on current practices; and describes test methods, design guidelines, and other products that may result from the research.
Imagine going to H&R Block to have your income taxes prepared and not knowing what to bring or what was going to happen when you got there. You would end up either making numerous trips back and forth to fetch receipts and so forth or else filing an incomplete or inaccurate tax return.
State and local highway agencies now have a new resource for help with implementing the Superpave system-namely, a specially trained team of 20 FHWA field engineers (see sidebar). The engineers will extend the reach of the Superpave Technology Delivery Team, which provides overall coordination and oversight for FHWA's Superpave program.
The researchers at WesTrack, the Federal Highway Administration's (FHWA) hot- mix asphalt test track in Nevada, were not surprised when several sections of the track had to be replaced in June. In its first year of operation, WesTrack had taken a beating from more than 2.8 million 80kN equivalent single-axle loads (ESALs), which caused severe rutting and fatigue cracking in many sections. What operators didn't expect was that those new sections would begin showing signs of permanent deformation after only a few days of service.
With winter fast approaching, 1, 300 highway maintenance workers and managers turned their thoughts to snow and ice at the Second Annual Eastern Winter Road Maintenance Symposium and Equipment Expo. Held in Hagerstown, Maryland, in September, the event was cosponsored by the Maryland Department of Transportation (DOT) and the Federal Highway Administration (FHWA), with the participation of Maryland's Transportation Authority, State Highway Administration, and Transportation Technology Transfer Center.