Compaction Properties of Alkali-Activated Fly Ash and Slag Blends with Demolition Wastes

Rapid growth in infrastructure development has been occurring for many years as a result of urbanization and rise in global population, especially in road construction, where natural virgin aggregate and cement binder have been used heavily. Such growth is considered unsustainable due to the steep decline of natural resources in the past decades, as well as the excessive carbon dioxide coming from the production of cement. This study focuses on solving such problems by replacing natural virgin aggregate with demolition wastes such as crushed brick, recycled concrete, and reclaimed asphalt and substituting cement with geopolymer binder. While demolition wastes as replacement materials is not a new idea, one-part geopolymer, however, is a completely novel and better technology when compared to traditional methods of binding aggregates, especially in terms of sustainability, quick preparation time, and potential strength improvement in pavement base. One-part geopolymer technology involves the incorporation of fly ash and slag as precursor mixture as well as an alkali activator (sodium hydroxide) to develop the structural bond among the main aggregates for the majority of its strength. This study will investigate the effectiveness of this technology while being used in pavement base application. Evaluation of compaction properties will be carried out using different extensive geotechnical laboratory tests in combination with some compressive strength tests so that a conclusion can be reached. As a major benefit, the adoption of demolition wastes and one-part geopolymer will reduce the carbon dioxide output significantly, making them sustainable for generations.