OTREC-RR-13-01

This Phase II investigation of the durability of new concrete containing recycled concrete aggregates (RCA) sought to corroborate Phase I results for a study of alkali-silica reactivity (ASR), investigate ASR mitigation methods, gather long-term outdoor placement data, and survey transportation agencies about their RCA perceptions and usage. Findings show the ASTM coefficient of variation limits do not apply when incorporating RCA. We recommend further testing to establish new standards.The survey showed sustainability was important to most agencies; 54%% had guidance for RCA use in new concrete, but only 15%% reported strong federal guidance; 77%% had concerns about ASR reaction; the biggest barriers to RCA use were quality issues, lack of standards, and unclear test guidance; the biggest RCA source concerns were shrinkage, ASR and residual chlorides. Data sought on RCA sources were condition at removal from service, reason for removal, whether the original structure needed repairs, and material age.