Utilización de la ceniza volcánica, con diferentes métodos de activación puzolánica, para la estabilización de suelos con resistencia a compresión menor a 80 KN/m2.

Abstract

The purpose of this undergraduate final project is to stabilize soft soils (with simple compressive strength less than 80kN/m2), by adding pozzolans from three different volcanoes in Ecuador: Cotopaxi (VC), Guagua Pichincha (VP) and Tungurahua (VT); and three alkaline activators (cement, quicklime and sodium hydroxide) in several proportions. To stabilize the soils, volcanic ashes are used due to its great potential as a cementing material, even though nowadays, these types of ashes are rarely used in the field of soil stabilization. For the experimental part of this study, physical and mechanical tests were carried out in the laboratory, such as: standard Proctor compaction, simple compression resistance (Curing periods of 28 and 56 days) and direct shear. Those tests were conducted on natural soil, standard samples and on specimens stabilized with 3% and 6% of volcanic ash considering the soil weight in optimal humidity, combined with 2% and 3% of each activator. In addition, X-ray diffraction analysis (XRD) and thermogravimetric analysis (TGA) were performed on the volcanic ash and standard samples, to obtain a mineralogical characterization and quantification. Finally, based on the results, it is verified that the volcanic ashes with alkaline activation can improve the mechanical and physical properties of the soil, as they considerably increase its resistance to simple compression and direct shear, compared to the natural soil.