Karakteristik Campuran Beton Aspal (AC-WC) Menggunakan Pasir Pantai sebagai Pengganti Agregat Halus

Abstract

Massive road infrastructure development requires a large supply of fine aggregate (sand), which often comes from conventional sources such as river or land quarries. Excessive exploitation of these sources leads to environmental problems, including ecosystem damage and changes in river morphology. This study aims to evaluate the characteristics of asphalt concrete wearing course (AC-WC) mixtures by utilizing beach sand as an alternative fine aggregate, while also identifying its potential as an eco-friendly solution. The research employed an experimental laboratory method. Beach sand from Binuang was used as a 100% substitute for standard fine aggregate. The quality of both coarse and fine aggregates was tested in accordance with SNI (Indonesian National Standard) standards. Subsequently, AC-WC mixtures were prepared at a predetermined optimum asphalt content (OAC) of 6.5%, and their Marshall characteristics were tested, including stability, flow, voids in the mix (VIM), voids filled with asphalt (VFA), and voids in mineral aggregate (VMA). The results indicate that the use of beach sand as a fine aggregate substitute to a certain percentage can meet the AC-WC mixture specifications required by Bina Marga (the Directorate General of Highways). The mixture with this optimal substitution percentage demonstrated the best Marshall characteristics, which remained within the specified range. At this percentage, the stability value reached 842 kg, flow 3.67 mm, VIM 4.12%, VMA 17.97%, VFA 77.23%, and Marshall Quotient (MQ) 233 kg/mm. These values demonstrate that the mixture has adequate performance. In conclusion, beach sand has the potential to be used as a partial substitute for fine aggregate in AC-WC mixtures, particularly at an optimal replacement percentage. The utilization of beach sand not only provides an abundant alternative material but also contributes to reducing the exploitation of conventional aggregates, making it a more economical and environmentally friendly solution for road infrastructure development. The novelty of this research lies in the identification of the optimum conditions for the use of beach sand as a substitute for fine aggregate in AC-WC mixtures based on a comprehensive evaluation of Marshall parameters. The results of the study indicate that although some mixtures meet stability, failure in volumetric parameters such as VIM and Marshall Quotient can still cause the mixture to be unsuitable. This study confirms that beach sand can be used as an alternative fine aggregate if used in certain proportions that are able to produce a balance between strength, flexibility, and density of the mixture