Comparative analysis between properties and microstructures of geopolymeric concrete and portland concrete

High energy consumption and elevated emission of carbon dioxide are relevant problems of the Portland cement industry related to environmental issues. With the purpose of reducing such problems, geopolymerics cements constitute a new class of materials used as mineral binder capable to replace Portland cement owing to technical and environmental advantages. These advantages, particularly the “ecologically friendly” aspect, have been questioned and are currently the subject of research works. As possible applications, geopolymeric cements are known to rapidly develop mechanical strength with aging while maintaining dimensional stability. By also considering the excellent adherence to aggregates make geopolymer cements potential materials for civil construction. Indeed, they are currently being investigated for the production of geopolymeric concrete as possible substitute for Portland cement concrete. In this work a combined comparison between mechanical, thermal and microstructure characteristics of concretes made with geopolymeric and high performance Portland cements is presented. Results of compressive strength, X-ray diffraction (XRD), scanning electron microscopy (SEM) and thermal analysis (DSC/TGA) are discussed, in order to gather information for a better understanding of the relation between properties and microstructure of both geopolymeric and Portland cements in the performance of concretes.