Guía para determinar la reacción álcali – agregado y su posible solución, como mecanismo de patología preventiva en la construcción de proyectos

Abstract

Concrete is a fundamental material in construction, but its durability is compromised by pathologies such as the alkali-aggregate reaction (AAR), an expansive process that causes cracking and loss of mechanical properties. Known as the “cancer of concrete” due to its irreversible damage and high repair costs, this pathology has driven the development of mitigation strategies, such as the addition of supplementary cementitious materials (SCM), including pozzolans. Although the effectiveness of these measures has been validated in laboratory settings, their validation under prolonged real service conditions remains limited, leaving a significant knowledge gap. This article addresses this gap through a 12-year (2014–2026) retrospective analysis of concrete in the parapet wall of the Hydroelectric Dam of a Colombian Electric Sector Company, where a 20% pozzolan addition was employed as a mitigation measure. The objective is to verify the efficiency of this strategy in preserving the mechanical properties and durability of concrete. The methodology compares historical construction data with current results from compressive strength tests, petrographic analysis, and scanning electron microscopy (SEM). This case study in critical infrastructure exposed to high humidity and thermal variability provides a unique opportunity to contribute empirical evidence on the long-term effectiveness of preventive measures against AAR.