Effect of Thermal Freeze/Thaw Cycles on the Rheological Behaviour of Limestone-Modified Bituminous Concrete

Abstract

The purpose of this article is to expand knowledge on the rheology of asphalt concrete with different percentages of limestone fines that have been affected by freeze-thaw thermal cycles. Freeze-thaw cycles cause swelling and settling in pavements, resulting in degradation of the pavement structure. Deformations start with small cracks and then develop parallel or perpendicular to the road axis. The sequence and frequency of freeze-thaw cycles lead to pavement deterioration, which can be transmitted to other layers of the road in the absence of prompt intervention measures. Degradation can take various forms, including deformations, cracks, detachment, and potholes. To simulate the freeze-thaw cycle phenomenon of asphalt concrete in the laboratory, a freezer and a temperature-controlled chamber were used to generate the real freeze-thaw cycle conditions in winter. The obtained results demonstrate that the addition of limestone filler proved to be highly significant as it ensured an increase in the dissipated energy based on the percentage of filler added to the mixture. After the application of freeze-thaw cycles, higher values of dissipated energy were obtained compared to the control sample. Freeze-thaw cycles have an effect on increasing the dissipated energy, which leads to improved resistance to cracking.