Concreto estructural liviano con agregados volcánicos del nevado del ruiz

Abstract

In order to produce a lightweight structural concrete using pyroclastic aggregates from the sector adjacent to the Nevado del Ruiz, the analysis of results of an experimental process is presented, based on a quantitative methodology that allowed the characterization of pyroclastic aggregates, their incorporation into concrete mixtures and analysis of the properties of concrete in fresh and hardened state. As a first approach to the ideal dosage, a first experimental phase was proposed, replacing the conventional aggregates with pyroclastic aggregates in proportions of 25%, 50% and 100% for the fine aggregate, and 25% and 50% for the coarse aggregate. In the process of characterizing the aggregates, it was found that the pyroclastic aggregates had an acidic pH, which an attempt was made to decrease with the incorporation of hydrated lime at 75% purity directly to the mixtures. It was identified that the use of pyroclastic materials decreases the workability of the concrete and that the mechanical properties of concrete in the hardened state with replacements of natural aggregates by pyroclastic aggregates decreased significantly with respect to the control mix. Starting from the results of the experimental phase one, the experimental phase two was proposed, in which a process of saturation of the pyroclastic aggregates with hydrated lime at 85% purity was carried out to control the acidity, the fine aggregate was replaced in proportions of 25%, 50%, 75% and 100%, seeking to improve resistance properties, 10% of silica fume was incorporated in 4 of the 9 mixtures. The results of the second experimental phase show that the mechanical properties of the concrete improved with respect to the results of phase one, reaching compression strengths higher than 17 MPa with equilibrium densities between 1804 kg / m3 and 2174 kg / m3. Finally, an analysis of the pyroclastic material deposits was carried out, which demonstrated the viability of mining in the area of influence of Nevado del Ruiz