Part 3: ICAR addresses highway need

摘要

Alkali-silica reactivity of aggregates and sue of recycled materials in highway construction filled out the agenda at ICAR's 9th Symposium.With a few exceptions - single presentations on high-fines concrete, roller-compacted concrete and manufactured sand m concrete - alkali-silica reaction (ASR) dominated the concrete portion of the International Center for Aggregates Research (ICAR) 9th Annual Symposium. Results of research on the validity of standard tests for ASR and on mitigation techniques filled two sessions.Several presentations focused on the accuracy and rapidity of screening tests to evaluate potentially reactive aggregate. The standard ASTM C1260 (mortar bar) and ASTM C1293 (prism) tests require significant time - up to one year - and sometimes indicate aggregates as reactive that have a history of good performance. Accelerated tests are in the process of being standardized, but these tests, taken alone, also can be inaccurate.