Análisis comparativo de las cenizas volcánicas provenientes de los volcanes Cotopaxi, Pululahua, Chalupas, Guagua Pichincha y Tungurahua para su uso en la fabricación de concreto.

Abstract

The purpose of this research project is to carry out a comparative analysis of nine types of volcanic ash from five volcanoes in Ecuador for use in concrete, based on the parameters of the ASTM C618-19 standard; using chemical analysis and physical tests described in the ASTM C311-18 standard. The research project allows obtaining detailed information on the chemical composition of nine volcanic ash samples, parameters that allow describing the differences between the percentages of oxides, moisture content, loss on ignition, available alkalis, and the percentage of ammonia. of each sample. Besides, based on the information obtained, an analysis of the concrete behavior can be achieved, when the cement is replaced by a percentage of volcanic ash, providing benefits in its chemical composition and the development of physical properties. The physical properties, analyzed in the project, were developed and evaluated using physical tests, such as the execution of the volcanic ash density test, the elaboration of mortar cubes, with a 20% replacement of cement by volcanic ash. , compression tested at 28, 56, and 90 days respectively, and the preparation of mortar bars with the same replacement percentage for the determination of shrinkage. From the results of the physical tests, which allow the classification and evaluation of volcanic ash, the pozzolanic activity index stands out, which is the variable that allows classifying volcanic ash to be used in the manufacture of concrete. The pozzolanic activity index or degree of reactivity is defined as the capacity and speed of reaction that a pozzolan has with calcium hydroxide to form cementitious compounds, giving rise to stable compounds with insoluble characteristics.