U.S. Department of Transportation
Federal Highway Administration
1200 New Jersey Avenue, SE
Washington, DC 20590
|Accelerating Infrastructure Innovations|
Publication Number: FHWA-SA-98-019
Date: February 1998
Alkali-silica reactivity (ASR), which occurs when silica in aggregates and alkalies in cement react with water to form a gel-like mass, can be a big problem for portland cement concrete bridges and pavements everywhere. Portland cement concrete is a highly durable material, yet ASR can cause concrete structures and pavements to crack and eventually fail. It's been 60 years since ASR was first identified, but recognizing and preventing ASR is still a daunting task for many highway agencies.
At the Lead States conference in St. Louis last fall, the American Association of State Highway and Transportation Officials (AASHTO) Task Force on SHRP Implementation recognized and thanked all seven teams for their initiative and hard work and then singled out the Lead States team for anti-icing/road weather information systems (RWIS) as best representing the goals of the Lead States program. In recognition of the team's work, the task force presented the team's members with AASHTO's 1997 Award for Distinguished Service.
Having trouble compacting a Superpave mix? Not sure what Superpave binder grade you need? Wondering how to plan your State's implementation of the Superpave system? For answers to your questions, try the Superpave Lead States team's pool of expertise. This team of experts from the Lead States, as well as their partners from academia and industry, is on call to answer your questions on the Superpave mix design system. The experts primarily provide technical assistance by phone. They also recommend other sources of information, such as technical reports.
To many people, thinking about the future means making plans for celebrating the millennium. But to a growing number of highway agencies, thinking about the future means designing and building bridges that will last for up to a century. That's more than twice as long as the life of a typical bridge-and it's made possible by a technology known as high-performance concrete (HPC).
Superpave: Today and Tomorrow presents an excellent opportunity for an individual or agency to learn about the overall Superpave system. Superpave researchers and other key people involved in Superpave implementation will discuss current research findings, the status of implementation efforts, and future activities. Featured sessions will include updates on Superpave binders, volumetric mix design, and performance testing.