Alkali-activated binary concrete based on a natural pozzolan: physical, mechanical and microstructural characterization

• Main Authors: R. Robayo-Salazar, R. Mejía de Gutiérrez, F. Puertas
• Format: Article
• Language: English
• Published: Consejo Superior de Investigaciones Científicas 2019-09-01
• Series: Materiales de Construccion
• Subjects: alkali-activated concrete; binary concrete; natural volcanic pozzolan; granulated blast furnace slag; mechanical and physical properties
• Online Access: http://materconstrucc.revistas.csic.es/index.php/materconstrucc/article/view/2255
• ISSN: 0465-2746; 1988-3226

This article presents the physical, mechanical and microstructural characterization of an alkali-activated binary concrete (AABC) based on a natural pozzolan (NP) of volcanic origin (70%) and granulated blast furnace slag (GBFS) (30%) cured at room temperature (25°C). A solution based on the combination of NaOH and waterglass (Na2SiO3·5H2O) was employed as an alkaline activator. The concrete design was obtained using a modified version of the “absolute volume” method (ACI 211.1). The performance of the AABC was similar and even superior to that of the reference concrete (OPC); e.g., it exhibited a compressive strength of up to 43.4 MPa at 360 days. These results demonstrate that the NP has potential for use in the industrial-scale production of these types of materials in the foreseeable future.