Evaluation of Coefficient of Thermal Expansion Test Protocol and Its Impact on Jointed Concrete Pavement Performance

Abstract

In order to determine the typical concrete paving mixture thermal expansion coefficient (CTE sub PCC) with mixture coarse aggregate derived from eight different Michigan sources, a laboratory investigation was conducted. Trap rock, gravel, slag, dolomite, and limestone were included in the primary aggregate class. The provisional AASHTO TP60 protocol was used to determine the CTE sub PCC. For each mixture-age combination, there was fabrication of three replicate test specimens. Prior to testing, there was moist curing of the test specimens for 3, 7, 14, 28, 90, 180, and 365 days. There was a 4.51 to 5.92 μe per degree F (8.11 to 10.65 μe per degree F) value range for average measured CTE sub PCC. That the number of heating and cooling cycles that the specimen is subjected to, the age of specimen at time of testing, and aggregate geology have statistically significant impacts (at 95% confidence level) on measured CTE sub PCC magnitude is indicated in test results. The test variables' practical impact on jointed plain concrete pavement transverse cracking performance is also discussed.