Evaluation of soil insulation effect on thermal behavior of drilled shafts as mass concrete

• Main Authors: Sangyoung Han, Sanghyun Chun, Kukjoo Kim, Adrian M. Lawrence, Mang Tia
• Format: Article
• Language: English
• Published: Taylor & Francis Group 2018-01-01
• Series: Cogent Engineering
• Subjects: mass concrete; drilled shaft; soil’s thermal properties; moisture content; maximum temperature difference
• Online Access: http://dx.doi.org/10.1080/23311916.2018.1468202

This study focused on investigating the early-age thermal behavior of drilled shafts under different surrounding soil’s thermal properties. Four 1.8 m (6 ft) diameter drilled shafts were constructed using two different concrete mixes and two different soil conditions. A finite element (FE) model was developed to estimate the temperature development of drilled shafts at early-age and validated using temperatures measured from full-scale drilled shafts constructed in the field. The validated analytical model was then used to perform a parametric analysis to evaluate the effects of the surrounding soils at different moisture conditions on change in thermal behavior of drilled shafts at early-age. Results indicated that the FE model developed was capable of accurately predicting temperature development of drilled shafts at early-age. A drier surrounding soil (i.e., gravimetric moisture content of 0% through 6%) was able to serve as a better insulating material that leads to reduced temperature difference in the drilled shafts. Also, it was identified the use of high-volumefly ash concrete mix in conjunction with relatively low heat of hydration can reduce the temperature difference in the drilled shaft.