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

摘要

A laboratory investigation was conducted to determine the coefficient of thermal expansion (CTE_(PCC)) of typical concrete paving mixtures made with coarse aggregate from eight different sources in Michigan. The primary aggregate class included limestone, dolomite, slag, gravel, and trap rock. The CTE_(PCC) was determined using the provisional AASHTO TP60 protocol. Three replicate test specimens were fabricated for each mixture-age combination. The test specimens were moist-cured for 3, 7, 14, 28, 90, 180, and 365 days prior to testing. The average measured CTE_(PCC) values ranged from 4.51 to 5.92 με/℉(8.11 to 10.65 με/℃). The test results indicated that aggregate geology, specimen age at the time of testing, and the number of heating-and-cooling cycles that the specimen is subjected to have a statistically significant (at a confidence level of 95%) impact on the magnitude of measured CTE_(PCC). The paper also discusses the practical impact of the test variables on the transverse cracking performance of jointed plain concrete pavements.