La investigación estudia experimentalmente las propiedades mecánicas de materiales granulares marginales, con el fin de determinar si son aptos para su utilización como subbases granulares en Colombia. El material de estudio es una subbase granular con tamaño máximo de 38 mm, en la cual se harán reemplazos de material pasa tamiz #200 por caolín y/o bentonita, cuyas características permiten crear una dosificación que sobrepasa los límites de plasticidad de las especificaciones. La primera parte de la investigación consistió en caracterizar los materiales que conforman la subbase granular SBG-38 (granulometría, hidrometría, equivalente de arena, peso específico de finos y gruesos, desgaste MicroDeval, desgaste en la Máquina de los Ángeles), posteriormente se definieron reemplazos de 5%, 10%, 15% y 20% de caolín y/o bentonita por el material pasa tamiz #200, estableciendo dos tipos diferentes de muestras, aquellas donde el reemplazo del material pasa tamiz #200 se hizo por 100% de caolín, y aquellas donde el reemplazo se llevó a cabo con un 90% de caolín y un 10% de bentonita, buscando cambiar el índice de plasticidad del material fino de la subbase granular. Después, mediante el ensayo de Proctor modificado se obtuvo la humedad óptima y el peso específico seco de los distintos tipos de muestras. Seguido, se fabricaron probetas para los distintos reemplazos con el fin de determinar su comportamiento mecánico mediante el ensayo CBR, ensayo de compresión simple (CS) y ensayo de resistencia a la tracción indirecta (RTI). Finalmente, se realizó la comparación de los valores de resistencia obtenidos con los requisitos de la norma vigente colombiana para la construcción de subbases granulares del INVIAS y se correlacionó el contenido de caolín y/o bentonita en las muestras, con los resultados de los ensayos de resistencia monotónica. Por último, se analizaron y compararon los resultados obtenidos, se determinó que los materiales granulares marginales son aptos, en términos de resistencia porcentual, para la construcción de subbases, siempre y cuando, el reemplazo de material pasa tamiz #200 por caolín y/o bentonita sea bajo. A pesar de esto, es importante resaltar que en términos de límites de consistencia el material de estudio no cumple con los mínimos establecidos en la normativa colombiana para subbases granulares, por lo cual, el drenaje se convierte en un parámetro de vital importancia para la aplicación de estos. The research experimentally studies the mechanical properties of marginal granular materials in order to determine their suitability for use as granular sub-bases for to determine if they are suitable for use as granular sub-bases in Colombia. Colombia. The study material is a granular subbase with a maximum size of 38 mm, in which replacements will be made of material passing sieve #200. The study material is a granular subbase with a maximum size of 38 mm, in which sieve #200 will be replaced by kaolin and/or bentonite, the characteristics of which allow for the creation of a dosage that exceeds characteristics allow creating a dosage that exceeds the plasticity limits of the specifications. The first part of the research consisted of characterizing the materials that make up the granular subbase SBG-38 granular subbase (granulometry, hydrometry, sand equivalent, specific weight of fines and coarse, fines and coarse specific weight of fines and coarse materials, MicroDeval wear, wear in the Angels Machine), later, replacements of 5%, 10%, 15% and 20% of kaolin and/or bentonite were defined for the material passing sieve #200, stable material passing sieve #200, establishing two different types of samples, those where the replacement of the sieve replacement of the #200 sieve-passing material was done with 100% kaolin, and those where the replacement was carried out with 90% kaolin. was carried out with 90% of kaolin and 10% of bentonite, seeking to change the plasticity index of the fine material of the plasticity of the fine material of the granular subbase. Then, by means of the modified Proctor The optimum moisture and dry specific weight of the different types of samples were obtained by the modified Proctor test samples. The optimum moisture content and dry specific weight of the different types of samples were then obtained using the modified Proctor test their mechanical behavior by means of the CBR test, simple compression test (CS) and indirect indirect tensile strength test (RTI). Finally, the strength values obtained were compared with the Finally, the strength values obtained were compared with the requirements of the current Colombian standard for the construction of granular sub-bases of the requirements of the current Colombian standard for the construction of granular subbases of the INVIAS and the kaolin and/or bentonite content in the samples was correlated, as well as the bentonite content in the samples was correlated with the results of the monotonic strength tests. Finally, the results of the monotonic strength tests were analyzed and compared, the results obtained were analyzed and compared, and it was determined that the marginal granular materials were suitable Finally, the results obtained were analyzed and compared, and it was determined that the marginal granular materials are suitable, in terms of percentage strength, for the construction of subbases, provided that the replacement of material passing sieve #200 by kaolin and/or bentonite is low. A Despite this, it is important to point out that in terms of consistency limits, the material under study does not meet the minimums established in the study material does not meet the minimums established in the Colombian standards for granular subbases. the drainage becomes a parameter of vital importance for the application of these materials. Pregrado