Study of concrete thermal properties for sustainable pavement design: Fid-Bau Portal

Study of concrete thermal properties for sustainable pavement design

Hu, J. / Wang, K. / Ge, Z.

Thermal properties, such as coefficient of thermal expansion (CTE) and thermal conductivity, are important parameters in pavement design. Improper use of aggregates or pavements with different thermal properties might result in extensive stresses and potential cracking in concrete pavement, which could lead to durability issues. In order to better understand thermal properties and to achieve sustainable pavement design, the present research was designed to determine thermal properties of typical Portland cement concrete (PCC) pavement used in the state of Iowa in USA. These properties are required as input values by the mechanistic-empirical pavement design guide (MEPDG) to be used in Iowa. In this research, a literature survey was conducted to determine the major factors that affect thermal properties of PCC, together with effects of concrete thermal properties on pavement behavior. In the laboratory study, CTE tests of various laboratory and field samples were performed. Variations due to test procedure, equipment used, and consistency of field batch materials were evaluated. The test results showed that concrete CTE values were significantly affected by different types of coarse aggregate. In addition, the thermal conductivity of a typical Iowa PCC mix and an asphalt cement concrete mix (both with limestone as coarse aggregate) were tested. The CTE and thermal conductivities of typical Iowa pavement were found to be different from the default values in the MEPDG program. Result indicated that appropriately documenting concrete thermal properties is essential for updating the typical material input values and providing rational concrete pavement design in future.