Rubio-Aguinaga, A. (Andrea)
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- Enhancement of latent heat storage capacity of lime rendering mortars(University of Ljubljana, Slovenia, 2022-09-21) Alvarez-Galindo, J.I. (José Ignacio); Rubio-Aguinaga, A. (Andrea); Navarro-Blasco, I. (Iñigo); Fernandez-Alvarez, J.M. (José María)Microencapsulated Phase Change Materials (PCMs) were included in air lime rendering mortars in order to improve the thermal comfort of the inhabitants and the energy efficiency of buildings of the Architectural Heritage under the premises of mínimum intervention and maximum compatibility. Three different PCMs were tested and directly added during the mixing process to fresh air lime mortars in three different percentages: 5, 10 and 20 wt. %. Some chemical additives were also incorporated to improve the final performance of the renders: a starch derivative as an adhesion booster; metakaolin as pozzolanic addition to shorten the setting time and to increase the final strength; anda polycarboxylated ether as a superplasticizer to adjust the fluidity of the fresh renders avoiding an excess of mixing water. The specific heat Cp, the enthalpy ti.H ascribed to the phase change and the melting temperature of the PCMs were determined by Differential Scanning Calorimetry (DSC). The capacity of the renders to store/release heat was demonstrated at a laboratory scale. The favourable results proved the effect of these PCMs w ith respect to the thermal performance of these rendering mortars, offering a promising way of enhancement of the thermal efficiency of building materiaIs of the Cultural Heritage.
- Green way of improving the thermal efficiency of mortars by the addition of biobased phase change materials(MATEC Web of Conferences, 2024-09-16) Alvarez-Galindo, J.I. (José Ignacio); Rubio-Aguinaga, A. (Andrea); Navarro-Blasco, I. (Iñigo); Fernandez-Alvarez, J.M. (José María)The thermal efficiency of air lime-based mortars was improved by directly integrating varying amounts (5 wt. %, 10 wt. %, and 20 wt. %) of a biobased Phase Change Material (PCM) into the fresh mortars. The composition of this PCM is vegetable oils and other organic wastes from the agri-food sector. To optimise the mortar formulation, different chemical additives and mineral admixtures were added. The mortar formulation was meticulously designed to produce rendering mortars that are easily workable, crack-free, and fully adherent for use in building envelopes. Positive outcomes in thermal efficiency tests have demonstrated the ability of these materials to store thermal latent energy, offering an environmentally friendly alternative to enhance the thermal comfort of building inhabitants.
- Obtaining of repair lime renders with microencapsulated phase change materials: optimization of the composition, application, mechanical and microstructural studies(University of Ljubljana, Slovenia, 2022-09-21) Alvarez-Galindo, J.I. (José Ignacio); Rubio-Aguinaga, A. (Andrea); Navarro-Blasco, I. (Iñigo); Fernandez-Alvarez, J.M. (José María)Different batches of repair lime rendering mortars were designed by mixing microencapsulated Phase Change Materials (PCMs) and other additives. The final aim of these renders is to improve the thermal efficiency of the envelope of the Built Heritage, while allowing the practitioners to apply a render with positive final performance. The combinations of the PCMs in different weight percentages, a superplasticiser (to increase the fluidity of the render keeping constant the mixing water), an adhesion improver and a pozzolanic additive were studied. The adhesion of these renders onto bricks and limestone specimens and the shrinkage and cracking of the mortars were studied in detail. X-ray diffraction technique was used to study the composition and evolution of the carbonation process. Compressive strength measurements were studied in hardened specimens. In addition, the porous structure of the rendering mortars was studied by mercury intrusion porosimetry to assess the effect of the PCMs' addition. Samples underwent accelerated climatic ageing to study their durability and the preservation of the thermal efficiency. Results have shown that these thermally enhanced mortars are feasible materia Is for real-life application in the context of architectural heritage restoration and conservation.
- Obtaining and characterization of air lime renders with phase change materials(Itecons, 2023) Alvarez-Galindo, J.I. (José Ignacio); Rubio-Aguinaga, A. (Andrea); Navarro-Blasco, I. (Iñigo); Fernandez-Alvarez, J.M. (José María)To improve the thermal efficiency of the building envelope of the architectural heritage buildings, modified air lime-based rendering mortars were designed with the addition of various microencapsulated phase change materials (PCMs) in proportions of 5, 10 and 20% by weight of lime. In a first part, the composition of the various renders was optimised by means of various additives, such as adhesion improvers, dispersing agents and a pozzolanic admixture (metakaolin). The characteristics of the rendering mortars were evaluated, including their adhesion on absorbent substrates, cracking, etc. The microstructure of the mortars was studied by optical microscopy, scanning electron microscopy and mercury intrusion porosimetry. It was found that the optimised recipes achieved an adequate distribution of PCM within the binding matrix, and with reasonable compatibility. The thermal effect on the render was studied by measuring thermal conductivities and enthalpies attributed to phase changes. In addition, a hotbox demo model was designed for the evaluation of the thermal performance. The results have shown that the addition of PCM in air lime renders is a feasible option to improve thermal efficiency and increase the thermal comfort of building occupants.
- Vaterite Calcined Clay Cement (VC3) as a Low-Carbon Solution(2024-10-21) Alvarez-Galindo, J.I. (José Ignacio); Kyriakou; Rubio-Aguinaga, A. (Andrea); Navarro-Blasco, I. (Iñigo); Nofalah, M.H. (Mohammad Hossein); Fernandez-Alvarez, J.M. (José María)Climate change, driven by rising CO2 levels, is a critical global challenge. Portland cement production, exceeding 4 Gt/year with demand projected to rise by 50%, significantly contributes to this issue. Consequently, there's growing interest in developing low-carbon cementitious binders to reduce the construction industry's environmental impact. This study explores vaterite, a metastable calcium carbonate polymorph, for its potential to enhance cementitious materials' sustainability and performance. Vaterite Calcined Clay Cement (VC3) is investigated as a lowCO2 alternative to traditional cement. Vaterite can sequester approximately 0.44 kg CO2 per kg produced and potentially has a lower manufacturing carbon footprint. Recent advancements have made large-scale vaterite production economically viable, contributing to significant CO2 emission reductions. A scalable vaterite production method was applied utilizing a rapid precipitation technique involving mixing at a 2:1:1 molar ratio of K2CO3, CaCl2, and NH4Cl solutions, followed by filtration and ethanol treatment. This method yields high-purity vaterite making it well-suited for cement applications. The study investigated the effects of varying vaterite content, cement reduction levels, and Metakaolin-to-Vaterite (MK/V) ratios on the compressive strength, and fresh state characteristics of VC3 formulations. Results demonstrated an enhancement of long-term compressive strength (ca. 60% to 80%) of OPC mortar at 28 days when replacing calcite with vaterite up to 15%. Reduction in cement content to 45% and 40% of the total binder proportion, resulted in average compressive strength decreases of 17% and 23%, respectively. Furthermore, results demonstrated that by decreasing MK/V ratio from 3 to 1, compressive strength increases from 20MPa to ca. 27 MPa, that indicates potential pathways for more sustainable formulations. Rheological analysis demonstrated that vaterite improves flowability about 5% compared to calcite, addressing a challenging aspect of traditional Limestone Calcined Clay Cement (LC3) systems. By increasing MK/V ratios from 1 to 3 a decrease in workability of ca. 6% is observed. The effectiveness of polycarboxylate ether (PCE) superplasticizer in enhancing rheology was confirmed across various mix designs. This comprehensive approach to VC3 optimization offers promising pathways for developing high-performance, low-carbon cementitious materials, contributing to the sustainable future of the construction industry and potentially enabling carbon capture at gigaton scales.
- Obtaining of repair lime renders with microencapsulated phase change materials: optimization of the composition, application, mechanical and microstructural studies(University of Ljubljana, Slovenia, 2022-09-21) Alvarez-Galindo, J.I. (José Ignacio); Rubio-Aguinaga, A. (Andrea); Navarro-Blasco, I. (Iñigo); Fernandez-Alvarez, J.M. (José María)Different batches of repair lime rendering mortars were designed by mixing microencapsulated Phase Change Materials (PCMs) and other additives. The final aim of these renders is to improve the thermal efficiency of the envelope of the Built Heritage, while allowing the practitioners to apply a render with positive final performance. The combinations of the PCMs in different weight percentages, a superplasticiser (to increase the fluidity of the render keeping constant the mixing water), an adhesion improver and a pozzolanic additive were studied. The adhesion of these renders onto bricks and limestone specimens and the shrinkage and cracking of the mortars were studied in detail. X-ray diffraction technique was used to study the composition and evolution of the carbonation process. Compressive strength measurements were studied in hardened specimens. In addition, the porous structure of the rendering mortars was studied by mercury intrusion porosimetry to assess the effect of the PCMs' addition. Samples underwent accelerated climatic ageing to study their durability and the preservation of the thermal efficiency. Results have shown that these thermally enhanced mortars are feasible materia Is for real-life application in the context of architectural heritage restoration and conservation.
- Green way of improving the thermal efficiency of mortars by the addition of biobased phase change materials(MATEC Web of Conferences, 2024-09-16) Alvarez-Galindo, J.I. (José Ignacio); Rubio-Aguinaga, A. (Andrea); Navarro-Blasco, I. (Iñigo); Fernandez-Alvarez, J.M. (José María)The thermal efficiency of air lime-based mortars was improved by directly integrating varying amounts (5 wt. %, 10 wt. %, and 20 wt. %) of a biobased Phase Change Material (PCM) into the fresh mortars. The composition of this PCM is vegetable oils and other organic wastes from the agri-food sector. To optimise the mortar formulation, different chemical additives and mineral admixtures were added. The mortar formulation was meticulously designed to produce rendering mortars that are easily workable, crack-free, and fully adherent for use in building envelopes. Positive outcomes in thermal efficiency tests have demonstrated the ability of these materials to store thermal latent energy, offering an environmentally friendly alternative to enhance the thermal comfort of building inhabitants.
- Study on the interaction of polymeric chemical additives with phase change materials in air lime renders(MDPI, 2024) Alvarez-Galindo, J.I. (José Ignacio); Rubio-Aguinaga, A. (Andrea); Navarro-Blasco, I. (Iñigo); Fernandez-Alvarez, J.M. (José María)The interaction of microencapsulated phase change materials (PCMs) with polymeric chemical additives in an air lime binding matrix was studied. These polymer-based additives included an adhesion booster (derived from starch) and a superplasticizer (polycarboxylate ether). Two different PCMs with melting points of 18 ◦C and 24 ◦C were assayed. The microcapsules were composed of melamine, with paraffin-based PCM cores. Measurements of zeta potential, particle size distribution, adsorption isotherms, and viscosity analyses were performed to comprehend the behavior of the polymer-based additives within the air lime matrix and their compatibility with PCMs. Zeta potential experiments pointed to the absence of a strong interaction between the lime particles and the microcapsules of PCMs. At the alkaline pH of the lime mortar, the negative charge resulting from the deprotonation of the melamine shell of the microcapsules was shielded by cations, yielding high positive zeta potential values and stable dispersions of lime with PCMs. The polycarboxylate ether demonstrated the ability to counteract the increase in mixing water demand caused by the PCM addition in the lime matrix. The dispersing action of the superplasticizer on the lime particles was seen to exert a collateral dispersion of the PCMs. Conversely, despite the positive values of zeta potential, the addition of the starch-based additive resulted in the formation of large PCM-lime clumps. Air lime renders incorporating 5, 10, and 20% PCMs by weight with various dosages of these chemical additives were experimented with until the optimal formulation for the specific application of the mortars as renderings was achieved. This fine-tuned formulation effectively tackled issues commonly associated with the addition of PCMs to mortars, such as poor adhesion, crack formation, and reduced fluidity.
- Incorporación de materiales de cambio de fase(2024-09-27) Alvarez-Galindo, J.I. (José Ignacio); Rubio-Aguinaga, A. (Andrea); Navarro-Blasco, I. (Iñigo); Fernandez-Alvarez, J.M. (José María)El mortero de cal se utiliza desde la antigüedad por sus propiedades mecánicas y durabilidad, lo que lo ha convertido en un material fundamental para la construcción de edificios históricos. Sin embargo, en las últimas décadas, su aplicación ha evolucionado. Hoy en día, no solo se utilizan en la restauración del patrimonio arquitectónico, sino también en proyectos que buscan sostenibilidad y eficiencia energética. Esta evolución ha abierto el camino a nuevas investigaciones, como la incorporación de materiales avanzados, como los materiales de cambio de fase (PCMs a partir de ahora por sus siglas en inglés), para mejorar su rendimiento térmico sin perder las características tradicionales del mortero.
- Air lime renders with microencapsulated phase change materials: assessment of microstructural and thermal properties(Elsevier, 2024-11-22) Alvarez-Galindo, J.I. (José Ignacio); Rubio-Aguinaga, A. (Andrea); Navarro-Blasco, I. (Iñigo); Fernandez-Alvarez, J.M. (José María)Microencapsulated phase change materials (PCMs) have been successfully integrated into air lime-based rendering mortars to enhance thermal properties, aiming to boost the thermal efficiency of the buildings in which are applied. Two microencapsulated PCMs, with melting points at 18℃ and 24℃, were seamlessly introduced into fresh rendering mortars in varying proportions (5%, 10%, and 20% by weight of lime), in formulations that include different chemical additives, such as a superplasticizer (polycarboxylate ether) and an adhesion enhancer (starch-based additive). In some mixes, metakaolin (MK) was also added as a mineral admixture. Starch addition was seen to promote the formation of aragonite and vaterite (calcium carbonate polymorphs), facilitating the smooth integration of microcapsules within the lime matrix. Hotbox simulations with tested materials containing as low as 0.01 - 0.04 g of PCM per gram of dry mortar, yielded outstanding energy efficiency values (822.4 and 732.8 kJ/m2, respectively, for PCMs with melting points at 18℃ and 24℃). Temperature attenuations of up to 6.1°C during the heating stage and up to 3.9°C during the cooling stages were observed. This outcome not only emphasizes the potential for enhancing thermal efficiency through PCM incorporation into air lime renders but also hints at a remarkable future for energy-efficient construction materials.