Browsing by Author "Pradena-Miquel, Mauricio"

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    Analysis of wood fly ash as sustainable alternative to cement replacement on concrete
    (2024) Ewert, Harold; Guinez, Felipe; Escribano, Daniella; Pradena-Miquel, Mauricio
    Supplementary cementitious materials (SCM) can contribute to reducing the carbon footprint of concrete. One of this SCM is the biomass fly ash (BFA) which is a waste of the wood production. Although different researchers have used BFA as SCM it is fundamental to know the concrete behaviour with local materials (including the available BFAs) to reduce the environmental impact of transportation. In particular, the Biobio region produces 57% of the Chilean wood, concentrated in Eucalyptus Globulus (E) and Pine Radiate (P) production. This paper describes the behaviour of concrete mixtures with replacements of BFAE or BFAP in 0%, 10% and 20% by weight of cement. Workability, compressive and flexural tests were performed, and the specimens were examined by scanning electronic microscopic (SEM) as well. The results show that BFAE reduced slump of fresh concrete and BFAP increased it on all cases due to their morphology. An increase in resistance at later ages is evident due to the increase in pozzolanic activity and BFAs morphology. The results indicate that BFAE and BFAP are suitable to replace at least 10% of cement, because those mixes present similar, and even higher, compressive and flexural strength than the control mix.
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    Efficient Bio-Based Insulation Panels Produced from Eucalyptus Bark Waste
    (2024) Fuentealba, Cecilia; Segovia, Cesar; Pradena-Miquel, Mauricio; Cesar, Andres G.
    Traditional thermal insulation panels consume large amounts of energy during production and emits pollutants into the environment. To mitigate this impact, the development of bio-based materials is an attractive alternative. In this context, the characteristics of the Eucalyptus fiber bark (EGFB) make it a candidate for insulation applications. However, more knowledge about the manufacturing process and in-service performance is needed. The present study characterized the properties that determine the in-service behavior of the EGFB insulation panel. The assessment involved two different manufacturing processes. The results indicated that the hot plates and the saturated steam injection manufacturing system can produce panels with similar target and bulk density. The thermal conductivity fluctuated between 0.064 and 0.077 W/mK, which indicated good insulation, and the values obtained for thermal diffusivity (0.10-0.37 m mm2/s) and water vapor permeability (0.032-0.055 m kg/GN s) are comparable with other commercially available panels. To guarantee a good in-service performance, the panels need to be treated with flame retardant and antifungal additive. The good performance of the panel is relevant because bio-based Eucalyptus bark panels generate less CO2 eq and require less energy consumption compared to traditional alternatives, contributing to the sustainability of the forestry and the construction industry.