Sources: Transtec Group, Austin, Texas; Federal Highway Administration
The FHWA's second of a two-part Alkali-Silica Reactivity focus, Report on the Diagnosis, Prognosis, and Mitigation of Alkali-Silica Reaction (ASR) in Transportation Structures (FHWA Report No. FHWA-HIF-09-004), assists state departments of transportation and other agencies in contending with a deleterious process in concrete structures. ASR occurs between alkali hydroxides in concrete's pore solution and certain types of aggregate; left untreated, it can lead to slab or structure expansion and cracking.FHWA initiated the ASR Development and Deployment Program in 2007, while Transtec is the prime contractor for implementation of ongoing research, which has augmented better ASR prevention and mitigation practice among transportation agencies. The first report, Determining the Reactivity of Concrete Aggregates and Selecting Appropriate Measures for Preventing Deleterious Expansion in New Concrete Construction (FHWA Report No. FHWA-HIF-09-001) was released in 2008. Both reports are available as free downloads from FHWA's ASR website. Additional information on the ASR Development and Deployment Program or reports can be obtained from FHWA's Gina Ahlstrom at [email protected] or Transtec's Bebe Resendez at [email protected].