Promoting the Circular Economy of Concrete Through Innovation in Asphalt Pavements

The circular economy is seeking to maximize the use of resources and reduceing the consumption of raw materials as well as waste generation. In a circular economy, the producer takes responsibility, directly or indirectly, for the waste generated by the production process and for their products at the end of their life cycle. This concept is being integrated in most countries to achieve an environmental and economic balance. This paper presents a work in which this concept is used, where the waste generated in a concrete research project (waste aggregates) were drawn on asphalt mixtures. This project consisted of using the fine aggregates as a total or partial replacement of raw aggregates to manufacture asphalt mixtures. These fine aggregates are generated in the production process of high-quality recycled concrete aggregates. In this research, an IV-A 12 semi-dense gradation size and a CA-24 asphalt binder were used, where four different percentages of natural aggregate replacement were evaluated (0%, 25%, 75% and 100%). These asphalt mixtures were evaluated in their compliance of Chilean standards, as well as their performance in different properties such as cracking and water sensitivity. The results obtained show that the mixtures with total replacement of raw aggregates can be used, since they fulfill the Chilean standards. However, taking into account the water sensitivity results, the percentage of suitable replacement would be 50% for the same binder content. According to the cracking results, it is noted that increasing the replacement content of the aggregates in the mixture increases the fracture resistance compared to the conventional hot mix asphalt.