Evaluación del comportamiento de las propiedades mecánicas del asfalto utilizando ceniza de cáscara de nuez con asfalto reciclado

Abstract

The incorporation of recycled materials in asphalt mixtures represents an innovative and sustainable alternative to reduce global pollution, aiming to offer benefits both in pavement quality and environmental preservation. This approach also contributes to waste reduction, optimizes the use of natural resources, and promotes more environmentally friendly and responsible construction practices in the long term. This process was developed in three stages. In the first, the appropriate site for collecting materials was selected. In the second, the materials were subjected to various tests, such as granulometry, abrasion, the Rice test, and the Marshall method, in order to evaluate their properties of stability, flow, air voids, and asphalt-filled voids. For the design, walnut shell ash and RAP were added, using optimal asphalt contents of 5.5, 6.0, and 6.5 percent. The walnut shell ash partially replaced the fine aggregate passing through the No. 4 sieve, while RAP partially replaced the intermediate aggregate of 3/8, passing through the half-inch sieve and being retained on the No. 4 sieve. Thus, walnut shell ash and RAP were incorporated in proportions of 7 percent ash – 10 percent RAP, 10 percent ash – 20 percent RAP, and 13 percent ash – 30 percent RAP. In the third phase, a comparative analysis of the modified asphalt mixtures and the conventional mixture was conducted using the Marshall method criteria.

The results showed that, by incorporating walnut shell ash and RAP in the mentioned proportions, most of the tests did not meet the mechanical property ranges of the mixture compared to the traditional one, concluding that the modified mixture does not outperform the conventional one in terms of resistance, durability, and environmental sustainability.