TY - GEN
T1 - Evaluation of Alkali-Silica reaction potential of aggregate using dilatometer method
AU - Shon, Chang Seon
AU - Mukhopadhyay, Anal K.
AU - Zollinger, Dan G.
PY - 2006
Y1 - 2006
N2 - Existing test methodology for alkali silica reactivity (ASR) are applicable to only a narrow band of accelerated conditions and doubts remain whether these methods have any relevance to concrete performance under field conditions. Aggregate reactivity is a key factor in predicting the concrete ASR and is a function of alkalinity, temperature, size and crystallinity. Recently developed at the Texas Transportation Institute, Texas A&M University, a testing apparatus called a dilatometer has been used to measure aggregate ASR expansion and introducing activation energy as a single parameter to represent aggregate ASR reactivity. The expansion-time characteristics as a function of temperature can be expressed by the term activation energy (Ea). The rationality of the dilatometer test procedure is explored by conducting comprehensive laboratory experiments related to the effects of test solution (NaOH) alkalinity, temperature and Ca2+ contents on Ea. Dilatometer measures the volumetric expansion due to ASR and accounts the direct measurement of expansion produced by the reaction products. Based on the test results, it is observed that this test method will be useful to evaluate ASR potential of aggregates based on their Ea within a very short period of time (e.g., within 3 days). The dependency of Ea on alkalinity, Ca2+ content and aggregate size provides a means to evaluate ASR potential of concrete relative to levels of alkali and temperature that occur under field conditions.
AB - Existing test methodology for alkali silica reactivity (ASR) are applicable to only a narrow band of accelerated conditions and doubts remain whether these methods have any relevance to concrete performance under field conditions. Aggregate reactivity is a key factor in predicting the concrete ASR and is a function of alkalinity, temperature, size and crystallinity. Recently developed at the Texas Transportation Institute, Texas A&M University, a testing apparatus called a dilatometer has been used to measure aggregate ASR expansion and introducing activation energy as a single parameter to represent aggregate ASR reactivity. The expansion-time characteristics as a function of temperature can be expressed by the term activation energy (Ea). The rationality of the dilatometer test procedure is explored by conducting comprehensive laboratory experiments related to the effects of test solution (NaOH) alkalinity, temperature and Ca2+ contents on Ea. Dilatometer measures the volumetric expansion due to ASR and accounts the direct measurement of expansion produced by the reaction products. Based on the test results, it is observed that this test method will be useful to evaluate ASR potential of aggregates based on their Ea within a very short period of time (e.g., within 3 days). The dependency of Ea on alkalinity, Ca2+ content and aggregate size provides a means to evaluate ASR potential of concrete relative to levels of alkali and temperature that occur under field conditions.
KW - Activation energy
KW - Alkali-silica reaction (ASR)
KW - Asr expansion
KW - Dilatometer
UR - http://www.scopus.com/inward/record.url?scp=33744900884&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=33744900884&partnerID=8YFLogxK
U2 - 10.1061/40838(191)55
DO - 10.1061/40838(191)55
M3 - Conference contribution
AN - SCOPUS:33744900884
SN - 0784408386
SN - 9780784408384
T3 - Proceedings of the 2006 Airfield and Highway Pavement Specialty Conference
SP - 646
EP - 658
BT - Airfield and Highway Pavements
PB - American Society of Civil Engineers (ASCE)
T2 - 2006 Airfield and Highway Pavement Specialty Conference
Y2 - 30 April 2006 through 3 May 2006
ER -