Sustainable Concrete Pavement Incorporating RAP and Fly Ash with Self-Sensing Properties

Abstract

This research focuses on addressing the problem of utilizing high-value sustainable materials in the creation of self-sensing concrete pavement. The study specifically explores the incorporation of reclaimed asphalt pavement (RAP), fly ash, and silica fume in a single mix design to achieve sustainability objectives. In the previous work by the authors, laboratory experiments were conducted to determine the optimal proportions of RAP, fly ash, and silica fume, with a focus on achieving desired mechanical properties. Mechanical tests, encompassing compressive strength, flexural strength, and indirect tensile strength, were conducted within this framework to assess the performance of the concrete mixture. The selected concrete mix in this study incorporated 40 % RAP as a replacement for virgin aggregate, a fly ash-to-cement ratio of 0,8, and the addition of silica fume at 8 % relative to the weight of cementitious materials. Structural health and durability were monitored in real time by embedding two electrodes within the concrete matrix. The results highlighted the significant impact of adding RAP, fly ash, and silica fume on the mechanical properties of the hardened concrete. The optimized combination design indicated improved strength and self-sensing behavior, which was related to the beneficial impacts of silica fume and fly ash on mechanical and self-sensing capabilities. This research contributes to the advancement of sustainable and intelligent infrastructure by demonstrating the feasibility of integrating recycled materials and self-sensing technology into concrete pavement construction. Additionally, the study extended its investigation to evaluate the performance of sustainable concrete under dynamic loads using ANSYS analysis. The investigation, which was performed on a structure with dimensions of 21 meters in length and 3 meters in width, observed that the use of sustainable materials improved the mechanical behavior of the structure under moving loads