ACI SP-320

Abstract

INTRODUCTION Alternative materials to reduce the carbon footprint of the cement and concrete industries have been widely studied in recent years [1-15]. Among the alternatives, the inclusion of high volume fly ash concretes, or 100% slag or fly ash concretes are some of the most viable options [3-4]. This work is focused on a hybrid system with 50% normal portland cement, 50% fly ash and sodium sulfate as an activator. Although in most research studies this system is seen to be technically viable, there are still questions about what really affects its performance, from the material technology to the concrete mixture proportion. Different fly ashes and activators including sodium sulfate, quicklime and lime are evaluated. Fly ash fineness and composition are related to mortar microstructure using X-ray fluorescence, X-ray diffraction and scanning electron microscopy analyses. The final objective is to identify the parameters influencing material performance and finding the most viable system.