Early hydration calorimetric study of the sewage sludge incinerated waste streams Portland cement-based binders: technological implications

The research study forms a part of the “Management of municipal water waste treatment plants potential by-products of sewage sludge ash type, as active or non-active additions to Portland cement-based binders” project’s outcomes (H2020-MSCA-IF-2016-746830). Based on the applied techniques characteristics (non-isothermal and non-adiabatic differential micro-calorimeter, SEM/EDS and XRF analysis), this study comprises the very first stage for a sustainable conversion of each of the considered 190114 and 190107* waste streams into a value-added by-product for specific constructive applications. Provided technical requirements regarding the designed cementitious products handling and suggested industrial application are focused on the early performance of the tested for quality and consistency, pastes, mortars and concretes. In detail, the obtained physical–chemical parameters show substantial differences of the original waste streams regarding their technological origin, seasonability and geographical localisation. Consequently, the calorimetric curves exhibit diverse early chemistry of the produced cements, showing the considerable variations in mineral nature (siliceous, aluminous) or hydraulic factor contents (reactive silica, SiO2r−, and reactive alumina, Al2O3r−) of the observed pozzolanic activities. Setting retarding phenomenon and shrinkage reducing effects are also carefully discussed. All the calorimetric and pozzolanic activity related data is contrasted with two other reference materials, fly ash and granulated blast furnace slag, standard behaviour.