Evaluation of the Specimen Saturation Criterion for the AASHTO T336 Test Method

Abstract

Abstract Realizing the importance of coefficient of thermal expansion (CTE) in concrete pavement design, the Federal Highway Administration conducted a ruggedness study for the AASHTO T336 test method in 2012. Of the seven variables that were evaluated as part of the ruggedness study, specimen saturation criterion was found to be one of the significant variables that warranted further investigation. This paper documents a follow-up study performed to specifically evaluate the effect of specimen saturation criterion on the measurement of CTE using the AASHTO T336 test method. CTE tests were conducted on multiple specimens from five concrete mixtures (two field and three laboratory prepared) at different levels of saturation in water: T336 criterion, 4 days, 7 days, 14 days, 28 days, and vacuum saturation. Data analysis from this study indicated that there is no statistical difference in CTE measurement after 28 days of water saturation versus T336 criterion, 4 days, 7 days, 14 days, and vacuum saturation. Based on this limited study, it appears that the current saturation criterion outlined in AASHTO T336 is adequate.