Case study of the dynamics of thermal expansion of concrete in pavements of South Kazakhstan

• Temperature, humidity, and free lime influence polymorphic transformations in cement minerals, affecting concrete's temperature expansion behavior. • The expansion coefficient can vary along different axes within the concrete volume, showing that thermal response is not uniform across a concrete slab. • The quantity of cement in concrete impacts expansion rates. This article explores the behaviour of concrete samples from road sections that have experienced warping due to temperature fluctuations. Warping refers to the curling of concrete slabs. The paper presents a novel approach to tracking the expansion and contraction of concrete joints over time. It analyses how the size and shape of concrete samples from cement-concrete (hereafter referred to as concrete) roads change under varying temperatures. Additionally, this study investigates the impact of temperature on concrete deformation. It was assumed that as the concrete's density and compressive strength increased, the linear expansion coefficient also increased. Furthermore, research has shown that this coefficient can vary along different axes within the concrete volume. This article describes the mechanism behind the deformations observed during the thermal expansion of concrete slabs and identifies the key factors influencing the buckling of concrete slabs as the air temperature rises. The temperature expansion may vary depending on the material's structure, as well as the constant polymorphic transformations of cement minerals within the concrete. These transformations are influenced by ambient temperature, humidity, and the presence of free lime. The factors affecting temperature expansion were determined to be the mineralogical composition of the cement, the concrete's strength class, and the cement content within the concrete.