Small-scale physical model tests have been increasingly used to study the thermomechanical soil-pile interaction, but existing model piles are highly simplified and do not have representative thermal properties or the quasi-brittle mechanical behavior of reinforced concrete (RC). This study aims to overcome these shortcomings by presenting a new type of model RC. This consists of a mortar (plaster, sand and water) with copper powder added to tune the mixture’s thermal properties, along with a steel reinforcing cage. Fine sand was used to represent geometrical scaling of the prototype aggregates to correctly capture quasi-brittle structural response. Adding copper powder content of 6% (by volume) matched the coefficient of thermal expansion and thermal conductivity of prototype concrete, without changing the axial and flexural properties of model piles. In 1-g soil-structure interaction tests, the model pile was able to serve as an effective heat exchanger for transferring heat from a water-carrying pipe embedded within the mortar to the surrounding soil. The model RC exhibited cyclic pile head settlement due to repeated pile heating/cooling.
|Number of pages||10|
|Journal||Journal of Geotechnical and Geoenvironmental Engineering|
|Early online date||13 Feb 2020|
|Publication status||Published - Apr 2020|
Zhao, R., Leung, A. K., Vitali, D., Knappett, J. A., & Zhou, Z. (2020). Small-Scale Modelling of Thermomechanical Behavior of Reinforced Concrete Energy Piles in Soil. Journal of Geotechnical and Geoenvironmental Engineering, 146(4), . https://doi.org/10.1061/(ASCE)GT.1943-5606.0002225