Journal of Science and Transport Technology University of Transport Technology JSTT 2022, 2 (1), 23-35 https://jstt.vn/index.php/vn Investigation of thermal stress in concrete pavement based on the finite element method Tran Nam Hung*, Pham Duc Tiep Military Techincal Academy, 236 Hoang-Quoc-Viet Street, Hanoi, Vietnam Article info Type of article: Original research paper *Corresponding author: E-mail address: tranhung@lqdtu.edu.vn Received: November 23, 2021 Accepted: Fabruary 14, 2022 Published: March 2, 2022 Abstract: The variation of ambient temperature in days causes thermal stress in the cement concrete slabs of the road rigid pavement. There have been many studies on this issue in the literature. However, because the thermal stress in the pavement depends a lot on the climatic condition of the region where the road is located, so this topic is still being interested by scientific community. In the technical standards of rigidpavement calculations of some countries, thermal stress is calculated from the temperature gradient between the concrete slab surface and slab bottom and this quantity is usually taken as a constant value. In fact, the temperature gradient varies continuously with depth from the slab surface. This paper presents the analysis of thermal stress state of concrete pavement caused by the nonlinear distribution of temperature in the slab. Ho Chi Minh City area temperature conditions were used. Numerical calculations in this study were based on the finite element method. The obtained results showed that the concrete pavement slab is continuously subjected to convex and concave bendings and the tensile and compressive thermal stresses occur at all positions in the slab depending on the time of day that could result in thermal fatigue damage of the pavement. Keywords: concrete pavement; thermal stress; temperature gradient; convex bending; concave bending.