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Circular Economy
The mortars were made with Portland cement type CEM II/A-V 42.5 R and the water relation (W/C) was 0.6 by weight. The cement was replaced in weight by fly ashes and GeoSilex®. The mixing procedure used was defined by the standard EN 1015-3 (1999). Two series of three prismatic specimens were prepared for each mortar mixture, 40 x 40 x 160 mm size, by casting them in steel forms. They were cured in a climatic chamber at 22 oC and 80 % of humidity up to 7 and 28 days; dried before testing.
Physical and mechanical properties after 7 and 28 days of curing time were determined. Apparent density and capillary water absorption determinations were carried out according to the standard EN 1015-10 (2000) and EN 1015-18 (2003) respectively. The compressive and flexural strength were determined using the Universal Testing Machine MTS 810, according to EN 1015-11 (2007).
3. Results and conclusions
The results show that the bulk density, compressive and flexion strength decrease as the Portland cement is replaced by fly ashes and GeoSilex® for both ratios (FA/GX =1/1 and FA/GX =2/1. However, the water absorption by capillarity is increased. The physical and mechanical properties are much more influenced for the FA / GX ratio = 2/1.
The mortars that incorporate 20% and 40% of residues for a FA/GX =1/1 ratio have suitable physical and mechanical properties, achieving important environmental benefits with their manufacture.
4. References
Velasco, J. G. (2009). Energías renovables. Editorial Reverte.
Criado Sanz, M., Palomo Sánchez, A., & Fernández Jiménez, A. (2006). Nuevos materiales cementales basados en cenizas volantes. Influencia de los aditivos en las propiedades reológicas. Madrid: Consejo Superior de Investigaciones Científicas.
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