%0 Journal Article
%A Caneda-Martínez, Laura
%A Monasterio, Manuel
%A Moreno-Juez, Jaime
%A Martínez-Ramírez, Sagrario
%A García, Rosario
%A Frías, Moisés
%T Behaviour and Properties of Eco-Cement Pastes Elaborated with Recycled Concrete Powder from Construction and Demolition Wastes
%D 2021
%U http://hdl.handle.net/11556/1101
%X This work analyses the influence of fine concrete fractions (<5 mm) of different natures—calcareous (HcG) and siliceous (HsT)—obtained from construction and demolition waste (C&DW)on the behaviour of blended cement pastes with partial replacements between 5 and 10%. The twoC&DW fractions were characterised by different instrumental techniques. Subsequently, their limefixingcapacity and the physico-mechanical properties of the blended cement pastes were analysed.Lastly, the environmental benefits of reusing these fine wastes in the manufacture of future ecoefficientcement pastes were examined. The results show that HsT and HcG exhibit weak pozzolanicactivity, owing to their low reactive silica and alumina content. Despite this, the new cement pastesmeet the physical and mechanical requirements of the existing regulations for common cements. Itshould be highlighted that the blended cement pastes initially showed a coarser pore network, butthen they underwent a refinement process between 2 and 28 days, along with a gain in compressivestrength, possibly due to the double pozzolanic and filler effect of the wastes. The environmentalviability of the blended cements was evaluated in a Life Cycle Assessment (LCA) concluding that theoverall environmental impact could be reduced in the same proportion of the replacement rate. Thisis in line with the Circular Economy goals and the 2030 Agenda for Sustainable Development.
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