Synthesis and characterization of Alkali Activated Cements based on Bottom Ash and Paval

Abstract

One of the most important challenges of European Union (EU) is to reduce the amount of municipal waste and industrial by-products generated since they are one of the main threats to the environment. For this reason, the valorisation of this waste and by-products has emerged, to produce compatible and viable products. If we focus on construction materials, some of these waste and by-products that have a large SiO2, Al2O3 and CaO content can be used to produce cements. Alkali Activated Cements (AAC) stands out as one of the best choices to produce this cements, since they can compete with Portland cements and they are also more sustainable. The main purpose of this project is to synthetize and study AAC based in two by-products: municipal waste incineration bottom ash and Paval, an industrial by-product generated in aluminium production, by using as alkaline activators NaOH and Na2SiO3. The results obtained in this project demonstrate that with this two by-products it is possible to synthetize AAC, and that their mechanical properties are good enough to study them in more detail to make them a real alternative to Portland cements. Different formulations have been considered by changing the proportions of this by-products and the alkali activators to determine which formulation gives rise to best results. It has been concluded that the AAC synthetized with bottom ash and 10% of Paval and activated with NaOH 6M are the formulations that give rise to better properties