Precast alkali-activated concrete towards sustainable construction

Abstract

Currently, the development of durable eco-efficient materials is a priority for the construction sector. In this regard, the alkaline activation of fly ash is a promising solution: it allows ordinary Portland cement (OPC), responsible for 5% of carbon dioxide emissions worldwide, to be replaced by an industrial by-product. Moreover, the resulting alkali-activated concrete (AAC) also presents an advantage, compared to OPC-based concrete, in terms of enhanced durability. The project herein described combines the huge advantage of AAC for the sustainability of the construction sector with the intrinsic characteristics of AAC that make it most suitable for the precast industry. The prefabrication of AAC façade panels was defined as the main goal, which makes this project one of the very few studies that refer to the production and the structural behaviour of AAC elements of considerable size. The following objectives were defined: (a) to study the properties of the AAC; (b) to develop the industrial production process of the AAC panels, including heat curing; and (c) to study the structural behaviour of the panels.