Page 69 - New Trends in Green Construction

STUDY OF THE APPLICABILITY OF FLY ASHES FROM OLIVE POMACE COMBUSTION AND GEOSILEX® IN SUSTAINABLE CONSTRUCTION MATERIALS
Jose L. Sánchez-Jiménez, Sofía Jurado-Contreras, M. Dolores La Rubia Dolores Eliche-Quesada
Keywords: Pomade fly ashes, GeoSilex®, mortars 1. Introduction
The Portland cement production is carried out at high temperature, which requires high energy and fossil fuels consumption. This process is considered very polluting due to the high emission of CO2 into the atmosphere, increasing greenhouse effect (Velasco, 2009). This situation leads to the search for new siliceous materials to replace cement, so the use of industrial wastes is a beneficial option for environmental and economic sustainability (Criado et al., 2006).
GeoSilex® is an additive that is obtained from the industrial waste generated in the acetylene production, whose energy and environmental cost has practically been amortized in the production phase of the waste by the product main (acetylene).
The main objective of this study is to analyze the use of fly ashes (FA) from the combustion of olive pomace and GeoSilex® (GX) as partial substitutes of Portland cement (CP) in the manufacture of mortars.
2. Materials and methods
The raw materials used in this investigation were Portland cement type CEM II/A-V 42.5 R (Holcim, Spain), sand CEN DIN-EN-196-1 from Instituto Torroja (Madrid, Spain), fly ashes from the olive pomace combustion supplied by the biomass Plant “La Loma” (Jaén, Spain) and GeoSilex® from Trenza Metal S.L. (Madrid, Spain). The fly ashes and the GeoSilex® were used in different percentages to partial replacement of cement.
The chemical composition of the raw materials was determined by X-ray fluorescence (XRF) by a spectrometer Philips Magix Pro (PW-2440). Crystalline phases were evaluated in a X-ray diffractometry with a X’Pert Pro MPD automated diffractometer (PANanalytical) equipped with Ge (111) primary monochromator, using monochromatic Cu Kα radiation (λ = 1.5406 Å) and an X’Celerator detector. The content of carbonates was determined by calcimetry. Blaine method. The relative density value was obtained by the Le Chatelier`s volumetric method. The pH was determined by a solid pH-meter PCE-PH20S, (PCE Instrument).
This work studied the effect of the addition of different proportions of wastes (20-60% wt), ratios fly ashes/GeoSilex® (1/1 and 2/1) and the curing time (7 and 28 days) on the final properties of mortars. The mortars obtained have been tested in accordance with the different international standards to obtain physical properties (apparent density and water absorption by capillarity) and mechanical properties (flexural and compressive strength). Likewise, the mineralogical composition of the samples has been analyzed by X-ray diffraction (XRD) and Infrared Spectroscopy (FT-IR) techniques.
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New Trends in Green Construction