Alkali-activated concretes based on fly ash and blast furnace slag: Compressive strength, water absorption and chloride permeability

Autor: Daniela Eugenia Angulo-Ramírez, William Gustavo Valencia-Saavedra, Ruby Mejía de Gutiérrez
Jazyk: angličtina
Rok vydání: 2020
Předmět:
Zdroj: Ingeniería e Investigación, Vol 40, Iss 2, Pp 72-80 (2020)
Druh dokumentu: article
ISSN: 0120-5609
2248-8723
DOI: 10.15446/ing.investig.v40n2.83893
Popis: Concretes based on alkaliactivated binders have attracted considerable attention as new alternative construction materials, which can substitute Portland Cement (OPC) in several applications. These binders are obtained through the chemical reaction between an alkaline activator and reactive aluminosilicate materials, also named precursors. Commonly used precursors are fly ash (FA), blast furnace slag (GBFS), and metakaolin. The present study evaluated properties such as compressive strength, rate of water absorption (sorptivity), and chloride permeability in two types of alkaliactivated concretes (AAC): FA/GBFS 80/20 and GBFS/OPC 80/20. OPC and GBFS/OPC* concretes without alkaliactivation were used as reference materials. The highest compressive strength was observed in the FA/GBFS concrete, which reported 26,1% greater strength compared to OPC concrete after 28 days of curing. The compressive strength of alkaliactivated FA/GBFS 80/20 and GBFS/OPC 80/20 was 61 MPa and 42 MPa at 360 days of curing, respectively. These AAC showed low permeability to the chloride ion and a reduced water absorption. It is concluded that these materials have suitable properties for various applications in the construction sector.
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