Production of Geopolymeric Mortars Containing Forest Biomass Ash as Partial Replacement of Metakaolin
AbstractGeopolymers are a new class of binders based on alkali activation of natural and by-products raw materials. Their properties and eco-compatibility highly depends on the reaction system. The (Na,K)2O-Al2O3-SiO2-H2O system shows a distinguishing pseudo-zeolitic network structure, but reaction requires a high amount of activators. The aim of this work is to investigate how the use of forest biomass ash (FBA), as partial replacement material in the production of metakaolin (MK) based geopolymeric mortar, and affect its properties. FBA is a by-product of the combustion process of forest biomass in thermal power plants. Mortars with a FBA content of 0%, 10%, 20%, and 30% wt have been tested for workability, flexural, and compressive strength. Capillary absorption, micro-morphological features, thermal, and shrinkage behavior have been investigated. The addition of FBA allowed for a decrease in the use of alkaline activator up to 20%, while preserving the characteristic broad hump centered at approximately 28° 2θ Mechanical properties of the geopolymeric mortars decrease proportionally with metakaolin replacement, even if a compression strength of more than 35 MPa is still obtained with a FBA content of 30% wt. After thermal cycles of up to 700 °C, all of the mortars still retain their cohesiveness, with an overall loss of mechanical strength of about 80% of the initial value that can be attributed to the formation of microcracks as a consequence of the network strain and distortion due to dehydration and shrinkage. View Full-Text
Share & Cite This Article
Candamano, S.; De Luca, P.; Frontera, P.; Crea, F. Production of Geopolymeric Mortars Containing Forest Biomass Ash as Partial Replacement of Metakaolin. Environments 2017, 4, 74.
Candamano S, De Luca P, Frontera P, Crea F. Production of Geopolymeric Mortars Containing Forest Biomass Ash as Partial Replacement of Metakaolin. Environments. 2017; 4(4):74.Chicago/Turabian Style
Candamano, Sebastiano; De Luca, Pierantonio; Frontera, Patrizia; Crea, Fortunato. 2017. "Production of Geopolymeric Mortars Containing Forest Biomass Ash as Partial Replacement of Metakaolin." Environments 4, no. 4: 74.
Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.