Evaluación técnico–normativa y socioambiental del aprovechamiento de estériles auríferos como sustituto de recebo en la construcción y mejoramiento de vías terciarias en marmato (Caldas, Colombia)

Abstract

The insufficient transitability of the tertiary road network in Colombia limits rural economic integration and raises logistical costs, partly due to dependence on conventional granular materials (subgrade) whose extraction and transport increase the cost of interventions in territories with complex topography. At the same time, the Marmato gold mining district (Caldas) generates significant volumes of waste rock, the improper management of which can increase the risk of instability and potential environmental impacts. Under a circular economy approach, the hypothesis arises that this waste rock could constitute a technically and environmentally viable substitute for subgrade in the roadbed layers of tertiary roads, provided it meets regulatory criteria and does not introduce geochemical risks. This study develops a systematic documentary evaluation (primarily sources ≤ 5 years old) to: identify applicable technical and regulatory parameters; Compile and organize reported data on the geotechnical and environmental properties of gold-bearing waste rock and analogous mining materials; compare their performance against required limits (liquid limit [LL], plasticity index [PI], California Bearing Ratio [CBR], durability, fines removal, and chemical parameters); and analyze socio-environmental benefits and risks (reduction in virgin aggregate extraction, mitigation of liabilities, rural accessibility, and potential geochemical impacts). Expected results include comparative matrices of compliance with particle size distribution, LL, PI, and CBR limits, sulfate soundness, and micro-DEVAL; identification of gaps between obtained and required parameters; and recommendations for tests and controls for a potential pilot phase. This provides an evaluative baseline to guide decisions on the sustainable management of mining waste and the improvement of rural road infrastructure within the framework of materials circularity.