Browsing by Keyword "Building and Construction"
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Item Analysis of life-cycle boundaries for environmental and economic assessment of building energy refurbishment projects(2017-02-01) Oregi, Xabat; Hernandez, Patxi; Hernandez, Rufino; Tecnalia Research & Innovation; PLANIFICACIÓN ENERGÉTICADespite the standardization of the life-cycle assessment methodology for the construction sector, analysts tend to apply some simplifications in relation to the system boundaries, omitting some of the life-cycle stages. In particular, for building energy refurbishment projects, there is a general focus on the operational stage, linked to the main objective of reducing operational energy use. This paper evaluates the relevance of each life-cycle stage in relation to the overall environmental and economic impact on residential building energy refurbishment projects. The results from the analysis of the refurbishment strategies at a case study in Spain show the relatively minor importance of the transport and end of life stages. The construction process stage is also of relatively minor importance regarding the environmental performance. The product, maintenance and replacement stages are generally of higher importance, particularly for economic evaluation. An extensive sensitivity analysis demonstrates the difficulties of simplifying the life-cycle boundaries, suggesting that potential simplifications should take into account various parameters, including the climate region, building typologies, and expected service life. As an example, the results have shown that for cold climate zones and buildings, where large energy savings from energy refurbishment strategies can be achieved, the other life-cycle phases are less important and, in most cases, represent less than 10% of life-cycle environmental impacts.Item An analysis of the potential of envelope-integrated solar heating and cooling technologies for reducing energy consumption in European climates(2018-06) Elguezabal, Peru; Arregi, Beñat; ECOEFICIENCIA DE PRODUCTOS DE CONSTRUCCIÓN; EDIFICACIÓN DE ENERGÍA POSITIVAThere is a clear trend towards the increased contribution of renewable energy at European level, and EU policies are oriented towards that direction. The building sector is no exception and presents an urgent necessity for increasing the share of renewable energy sources (RES) to reduce the impact on the environment. The aim of this paper is to examine the potential of solar heating and cooling technologies in reducing energy consumption by incorporating solar thermal and PV collectors within the building’s envelope. Although generally envisaged to be integrated in the roof, preferably oriented to the south, this study explores also their potential for integration into the façades. External climate influences both the demand for space heating and cooling (influenced by temperature) and the potential from solar renewable energy (incident global irradiation). However, a time lag exists since supply and demand peak at different times within the day as well as during the year. This study assesses the interplay of solar energy supply with heating and cooling energy demand. An analysis is performed over climate data files for five European locations, based on daily weather data. Besides the extent of incident solar irradiation, its seasonal usability is assessed with regard to the thermal demand. The impact of the inclination of solar collector devices is assessed by comparing their placement on a horizontal plane, on the inclination of maximum exposure for each climate, and on vertical planes for the four cardinal directions. As a conclusion, the utilization of solar energy for different scenarios is assessed and a discussion on the integration of solar thermal and PV collectors over façades is presented, building on the potential of these technologies for developing innovative solutions that could significantly upgrade the buildings’ energy performance in the near future.Item Applications of Models and Tools for Mesoscale and Microscale Thermal Analysis in Mid-Latitude Climate Regions—A Review(2021-11-10) Lobaccaro, Gabriele; De Ridder, Koen; Acero, Juan Angel; Hooyberghs, Hans; Lauwaet, Dirk; Maiheu, Bino; Sharma, Richa; Govehovitch, Benjamin; Tecnalia Research & InnovationUrban analysis at different spatial scales (micro- and mesoscale) of local climate conditions is required to test typical artificial urban boundaries and related climate hazards such as high temperatures in built environments. The multitude of finishing materials and sheltering objects within built environments produce distinct patterns of different climate conditions, particularly during the daytime. The combination of high temperatures and intense solar radiation strongly perturb the environment by increasing the thermal heat stress at the pedestrian level. Therefore, it is becoming common practice to use numerical models and tools that enable multiple design and planning alternatives to be quantitatively and qualitatively tested to inform urban planners and decision-makers. These models and tools can be used to compare the relationships between the micro-climatic environment, the subjective thermal assessment, and the social behaviour, which can reveal the attractiveness and effectiveness of new urban spaces and lead to more sustainable and liveable public spaces. This review article presents the applications of selected environmental numerical models and tools to predict human thermal stress at the mesoscale (e.g., satellite thermal images and UrbClim) and the microscale (e.g., mobile measurements, ENVI-met, and UrbClim HR) focusing on case study cities in mid-latitude climate regions framed in two European research projects.Item Assessment on the Efficiency of an Active Solar Thermal Facade: Study of the Effect of Dynamic Parameters and Experimental Analysis When Coupled/Uncoupled to a Heat Pump: Study of the effect of dynamic parameters and experimental analysis when coupled/uncoupled to a heat pump(2020) Elguezabal, Peru; Lopez, Alex; Blanco, Jesus Maria; Chica, Jose Antonio; ECOEFICIENCIA DE PRODUCTOS DE CONSTRUCCIÓN; SGThe building sector presents poor performance in terms of energy efficiency and is looking for effective alternatives aimed at reducing the use of fossil fuels. The facade is a key element able to harness renewable energy as an Active Solar Thermal Facade (ASTF). The main purpose of this study is the assessment of a novel design concept based on a steel sandwich panel technology. The performance of the active system will be first addressed by a parametric study in order to analyze its behavior and secondly, by describing a real case based on an experimental test by connecting the active panels to a heat pump. The study shows the impact of solar irradiation and mass flow on the thermal jump achieved, while ambient and fluid inlet temperatures are the most influencing parameters in the efficiency of the facade. When coupled to the heat pump, results from a measurement campaign demonstrate a remarkable improvement in the performance of the ASTF. The results presented provide significant proof about the benefits of a synergetic combination of both technologies—solar facades and heat pumps—as efficient alternatives for the building sector, aiming to improve energy efficiency as well as reduce their dependence on non-renewable sources.Item Automatised and georeferenced energy assessment of an Antwerp district based on cadastral data(2018-08-15) Oregi, Xabat; Hermoso, Nekane; Prieto, Iñaki; Izkara, Jose Luis; Mabe, Lara; Sismanidis, Panagiotis; Tecnalia Research & Innovation; PLANIFICACIÓN ENERGÉTICA; LABORATORIO DE TRANSFORMACIÓN URBANAMunicipalities play a key role in supporting Europe's energy transition towards a low-carbon economy. However, there is a lack of tools to allow municipalities to easily formulate a detailed energy vision for their city. Nevertheless, most municipalities have access to georeferenced cartographic and cadastre information, including that on basic building characteristics. This article describes an innovative method to calculate and display the current hourly thermal energy demand for each building in a district based on basic cartography, cadastre, and degree-day values. The method is divided into two main blocks: (1) input data processing to obtain geometric information (e.g. geolocation, building and facades’ dimensions) and semantic data (e.g. use, year of construction), and (2) district energy assessment to calculate the thermal energy demand using data obtained in block 1. The proposed method has been applied and tested in the historical district of Antwerp. The reliability and thoroughness of the results obtained using the method are demonstrated based on two different validations: (1) comparison of the results with those calculated using an existing dynamic energy simulation tool, and (2) comparison of the results with the real gas consumption of a partial sector of the selected district. The first validation shows that the average difference between the two methodologies is less than 11% for the heating demand, less than 11% for the cooling demand, and less than 15% for the domestic hot water demand. The second validation shows a 24% difference between the real natural gas consumption and that obtained by new methodology. Finally, the results have been presented to the municipality of Antwerp, which plans to use the method to design the district heating expansion within the city centre. Furthermore, sensitivity assessment was used to determine the relevance of the main input parameters considered in this method, such as the base temperature, energy system schedules, window-to-wall ratio, and solar gains.Item BIM4Ren: Barriers to BIM Implementation in Renovation Processes in the Italian Market: Barriers to BIM implementation in renovation processes in the Italian market(2019-09-01) Elagiry, M.; Marino, V.; Lasarte, N.; Elguezabal, P.; Messervey, T.; E&I SEGURAS Y RESILIENTES; ECOEFICIENCIA DE PRODUCTOS DE CONSTRUCCIÓNAs a part of BIM4REN (Building Information Modelling based tools & technologies for fast and efficient RENovation of residential buildings) H2020 project, an analysis of the barriers of the renovation process, the potential of digitalization to overcome those barriers, and the requirements to ensure a successful digital workflow. This paper focuses on the Italian market where surveys, interviews, and a workshop were conducted, and then a diagnosis was made on the results obtained. Results show that technological innovation on BIM tools cannot be a stand-alone action to reach a full digitalization of the renovation sector, but it shall be supported by a major awareness of the actors involved, improved skills, and competences, as well as an important change of approach in the current construction practice.Item Bonding strength of stainless steel rebars in concretes exposed to marine environments(2018-05-30) Calderon-Uriszar-Aldaca, I.; Briz, E.; Larrinaga, P.; Garcia, H.; Tecnalia Research & InnovationMany studies have corroborated the use of Stainless Steel Reinforcements (SSR) for structures in corrosive environments. However, even though the conditions for their employment are specified in different standards, their use is always tied to the same requirements for standard carbon steel rebars (B500SD), among which an equivalent carbon content for weldability that is inappropriate for SSR. Further studies are therefore needed to develop suitable standards that will focus on addressing not only the content, but also the technical advantages of SSR for structural engineering under specific conditions. The results of this study show improvements in the maximum bond strength behaviour of different SSRs in simulated marine environments, in comparison with B500SD, in terms of several variables: Bond index, curing time, w/c ratio, and corrosion. Specifically, the test results showed that: (a) the Bond index was not a suitable parameter for the evaluation of the bonding strength of SSR; (b) the curing time increased the bonding strength of Lean Duplex Stainless Steel (LDSS); (c) a higher w/c ratio tended to decrease bond strength, although less so in LDSS; and, (d) corrosion reduced bond strength, especially in B500SD.Item Cable-driven parallel robot for curtain wall module installation(2022-06) Iturralde, K.; Feucht, M.; Illner, D.; Hu, R.; Pan, W.; Linner, T.; Bock, T.; Eskudero, I.; Rodriguez, M.; Gorrotxategi, J.; Izard, J.B.; Astudillo, J.; Cavalcanti Santos, J.; Gouttefarde, M.; Fabritius, M.; Martin, C.; Henninge, T.; Nornes, S.M.; Jacobsen, Y.; Pracucci, A.; Cañada, J.; Jimenez-Vicaria, J.D.; Alonso, R.; Elia, L.; Normes, S. M.; DIGITALIZACIÓN Y AUTOMATIZACIÓN DE LA CONSTRUCCIÓN; ROBOTICA_AUTOMA; Tecnalia Research & InnovationA cable-driven parallel robot (CDPR) was developed for the installation of curtain wall modules (CWM). The research addressed the question of whether the CDPR was capable installing CWMs with sufficient accuracy while being competitive compared to conventional manual methods. In order to develop and test such a system, a conceptual framework that consisted of three sub-systems was defined. The tests, carried out in two close-to-real demonstration buildings, revealed an absolute accuracy of the CWM installation of 4 to 23 mm. The working time for installing a CWM was reduced to 0.51 h. The results also show that the system is competitive for a workspace greater than 96 m2 compared to conventional manual methods. However, improvements such as reducing the hours for setting up the CDPR on the one hand and achieving a faster and more robust MEE on the other hand will be still necessary in the future.Item Carbon-Free Electricity Generation in Spain with PV–Storage Hybrid Systems(2022-06-29) Fraile Ardanuy, Jesús; Alvaro-Hermana, Roberto; Castano-Solis, Sandra; Merino, Julia; Tecnalia Research & InnovationClimate change motivated by human activities constitutes one of the main challenges of this century. To cut carbon emissions in order to mitigate carbon’s dangerous effects, the current energy generation mix should be shifted to renewable sources. The main drawback of these technologies is their intermittency, which will require energy storage systems to be fully integrated into the generation mix, allowing them to be more controllable. In recent years, great progress to develop an effective and economically feasible energy storage systems, particularly motivated by the recent rise of demand for electric transportation, has been made. Lithium-ion (Li-ion) battery prices have fallen near 90% over the past decade, making possible the affordability of electric vehicles and transforming the economics of renewable energy. In this work, a study on storage capacity demand previously presented as conference paper is expanded, including a deep analysis of the Spanish generation mix, the evaluation of the energy storage requirements for different low-carbon and carbon-free scenarios in Mainland Spain, and the calculation of the CO2 emissions’ reduction and the associated storage costs.Item Characterisation of cement pastes with innovative self-healing system based in epoxy-amine adhesive(2015-07-01) Perez, G.; Gaitero, J. J.; Erkizia, E.; Jimenez, I.; Guerrero, A.; Tecnalia Research & Innovation; ECOEFICIENCIA DE PRODUCTOS DE CONSTRUCCIÓNTwo innovative additions are considered for the development of self-healing concrete: epoxy-containing silica microcapsules and amine-functionalized nanosilica. The effect of two concentrations of the additions on the microstructure of a cement paste with silica fume is studied. The results indicate a proper dispersion of the additions within the matrix, a pozzolanic reaction induced by nanosilica and the stability of the microcapsules that reliably isolate the epoxy from the paste. As the concentration of additions increases, a preferential orientation of the portlandite phase is observed, together with a decrease of the compressive strength due to the presence of a minor content of macropores and to the low strength of the capsules. The self-healing efficiency is confirmed in concrete specimens for 150 μm wide cracks and a particular concentration of the additions. These results will be essential for the subsequent development of a reliable self-healing concrete based in the epoxy-amine adhesive.Item Characterization and thermal performance evaluation of infrared reflective coatings compatible with historic buildings(2018-04-15) Becherini, Francesca; Lucchi, Elena; Gandini, Alessandra; Casado Barrasa, Maria; Troi, Alexandra; Roberti, Francesca; Sachini, Maria; Di Tuccio, Maria Concetta; Garmendia Arrieta, Leire; Pockelé, Luc; Bernardi, Adriana; Tecnalia Research & Innovation; LABORATORIO DE TRANSFORMACIÓN URBANATwo infrared reflective coatings recently developed as part of the EFFESUS European research project are characterized and evaluated in this paper. Thermal performance, durability, compatibility with historic fabric, and reversibility are all analysed. The results of extensive research that include laboratory analysis of selected substrates, measurements on a large-scale traditional masonry mock-up, thermodynamic simulations, and finally application in to a real historic building in Istanbul, all support the potential of the new coatings to improve the thermal performance of historic buildings, in keeping with their visual integrity and cultural value. Besides their reflective properties, proven by the thermal stress reductions on the treated surfaces, the new coatings are characterized by low visual impact, easy application, material compatibility, and reversibility after application, as well as durability over time.Item Comparison between Energy Simulation and Monitoring Data in an Office Building(2021-12-30) Martin-Escudero, Koldobika; Atxalandabaso, Garazi; Erkoreka, Aitor; Uriarte, Amaia; Porta, Matteo; EDIFICACIÓN DE ENERGÍA POSITIVA; Tecnalia Research & InnovationOne of the most important steps in the retrofitting process of a building is to understand its pre-retrofitting stage energy performance. The best choice for carrying this out is by means of a calibrated building energy simulation (BES) model. Then, the testing of different retrofitting solutions in the validated model allows for quantifying the improvements that may be obtained, in order to choose the most suitable solution. In this work, based on the available detailed building drawings, constructive details, building operational data and the data sets obtained on a minute basis (for a whole year) from a dedicated energy monitoring system, the calibration of an in-use office building energy model has been carried out. It has been possible to construct a detailed white box model based on Design Builder software. Then, comparing the model output for indoor air temperature, lighting consumption and heating consumption against the monitored data, some of the building envelope parameters and inner building inertia of the model were fine tuned to obtain fits fulfilling the ASHRAE criteria. Problems found during this fitting process and how they are solved are explained in detail. The model calibration is firstly performed on an hourly basis for a typical winter and summer week; then, the whole year results of the simulation are compared against the monitored data. The results show a good agreement for indoor temperature, lighting and heating consumption compared with the ASHRAE criteria for the mean bias error (MBE).Item A comparison of thermal comfort conditions in four urban spaces by means of measurements and modelling techniques(2015-11-01) Acero, Juan A.; Herranz-Pascual, Karmele; Tecnalia Research & Innovation; CALIDAD Y CONFORT AMBIENTALMicroclimatic conditions inside urban areas depend on the result of the interaction of the regional climate with the whole urban area and on the local characteristics of the urban development. Inadequate human thermal comfort conditions can affect quality of life and the use of public open spaces. In this study, outdoor thermal conditions are examined through three field campaigns in Bilbao in the north of the Iberian Peninsula. Climate variables are measured in four different areas of the city in different regional climate conditions. Thermal comfort evaluation is undertaken by means of the thermal index PET (Physiological Equivalent Temperature). Measurements are compared with estimated values derived from ENVI-met model. Results show that the differences between modelled and measured climatic variables can imply a relevant deviation in PET (i.e. difference between modelled and measured values). Regression and correlation analyses account for the importance of the deviation of each climatic variable in the deviation of PET values. Deviation of PET appears to be highly conditioned by the deviation of mean radiant temperature values especially during clear sky days. Under overcast conditions deviation of wind speed also becomes a relevant aspect. Consequently, reliable estimation of these variables is required if modelling techniques are to be used in the assessment of thermal comfort in outdoor urban spaces.Item Comprehensive study on the most sustainable concrete design made of recycled concrete, glass and mineral wool from C&D wastes(2021-03-01) Gebremariam, Abraham T.; Vahidi, Ali; Di Maio, Francesco; Moreno-Juez, J.; Vegas-Ramiro, I.; Łagosz, Artur; Mróz, Radosław; Rem, Peter; TRAZABILIDAD CIRCULAR; GENERALThis study focuses on formulating the most sustainable concrete by incorporating recycled concrete aggregates and other products retrieved from construction and demolition (C&D) activities. Both recycled coarse aggregates (RCA) and recycled fine aggregates (RFA) are firstly used to fully replace the natural coarse and fine aggregates in the concrete mix design. Later, the cement rich ultrafine particles, recycled glass powder and mineral fibres recovered from construction and demolition wastes (CDW) are further incorporated at a smaller rate either as cement substituent or as supplementary additives. Remarkable properties are noticed when the RCA (4–12 mm) and RFA (0.25–4 mm) are fully used to replace the natural aggregates in a new concrete mix. The addition of recycled cement rich ultrafines (RCU), Recycled glass ultrafines (RGU) and recycled mineral fibres (RMF) into recycled concrete improves the modulus of elasticity. The final concrete, which comprises more than 75% (wt.) of recycled components/materials, is believed to be the most sustainable and green concrete mix. Mechanical properties and durability of this concrete have been studied and found to be within acceptable limits, indicating the potential of recycled aggregates and other CDW components in shaping sustainable and circular construction practices.Item Contact angle measurement for LiBr aqueous solutions on different surface materials used in absorption systems(2018-11) Martinez-Urrutia, Asier; Fernández de Arroiabe, Peru; Ramirez, Miguel; Martinez-Agirre, Manex; Mounir Bou-Ali, M.; Tecnalia Research & Innovation; SISTEMAS TÉRMICOS EFICIENTESWetting surface is a very important issue for the design of absorption applications and heat exchangers. The contact angle is deemed essential in wettability studies; However, LiBr aqueous solution contact angle studies are limited. This work analyses the contact angle of LiBr aqueous solution in the range of 0–55% mass fraction on different material surfaces: copper, aluminum, stainless-steel and polytetrafluoroethylene (PTFE) under atmospheric conditions. A sessile drop technique was used for measuring the contact angles, and a linear relation between solution surface tension and contact angle is observed in the tested materials. The study of three metals show hydrophilic performance (θ < 90°), whereas the PTFE shows hydrophobic performance. Additionally, the effect of the selection of the material, and consequent effect on the contact angle, on the minimum wetting rate and film thicknesses is presented under the working conditions of the absorption technologies. From the wettability point of view, the results show that using stainless-steel and aluminum leads to a slightly better performance than a copper made heat exchanger.Item Control Room Requirements for Voltage Control in Future Power Systems(2018) Coelho, António; Soares, Filipe; Merino, Julia; Riaño, Sandra; Peças Lopes, João; Tecnalia Research & Innovation; SISTEMAS FOTOVOLTAICOSIn future power grids, a large integration of renewable energy sources is foreseen, which will impose serious technical challenges to system operators. To mitigate some of the problems that renewable energy sources may bring, new voltage and frequency control strategies must be developed. Given the expected evolution of technologies and information systems, these new strategies will benefit from increasing system observability and resources controllability, enabling a more efficient grid operation. The ELECTRA IRP project addressed the new challenges that future power systems will face and developed new grid management and control functionalities to overcome the identified problems. This work, implemented in the framework of ELECTRA, presents an innovative functionality for the control room of the cell operator and its application in assistance with the voltage control designed for the Web-of-Cells. The voltage control method developed uses a proactive mode to calculate the set-points to be sent to the flexible resources, each minute, for a following 15-min period. This way, the voltage control method developed is able to mitigate voltage problems that may occur, while, at the same time, contributes to reduce the energy losses. To enable a straightforward utilization of this functionality, a user interface was created for system operators so they can observe the network state and control resources in a forthright manner accordingly.Item Data driven model for heat load prediction in buildings connected to District Heating by using smart heat meters(2022-01-15) Lumbreras, Mikel; Garay-Martinez, Roberto; Arregi, Beñat; Martin-Escudero, Koldobika; Diarce, Gonzalo; Raud, Margus; Hagu, Indrek; Tecnalia Research & Innovation; EDIFICACIÓN DE ENERGÍA POSITIVAAn accurate characterization and prediction of heat loads in buildings connected to a District Heating (DH) network is crucial for the effective operation of these systems. The high variability of the heat production process of DH networks with low supply temperatures and derived from the incorporation of different heat sources increases the need for heat demand prediction models. This paper presents a novel data-driven model for the characterization and prediction of heating demand in buildings connected to a DH network. This model is built on the so-called Q-algorithm and fed with real data from 42 smart energy meters located in 42 buildings connected to the DH in Tartu (Estonia). These meters deliver heat consumption data with a 1-h frequency. Heat load profiles are analysed, and a model based on supervised clustering methods in combination with multiple variable regression is proposed. The model makes use of four climatic variables, including outdoor ambient temperature, global solar radiation and wind speed and direction, combined with time factors and data from smart meters. The model is designed for deployment over large sets of the building stock, and thus aims to forecast heat load regardless of the construction characteristics or final use of the building. The low computational cost required by this algorithm enables its integration into machines with no special requirements due to the equations governing the model. The data-driven model is evaluated both statistically and from an engineering or energetic point of view. R2 values from 0.70 to 0.99 are obtained for daily data resolution and R2 values up to 0.95 for hourly data resolution. Hourly results are very promising for more than 90% of the buildings under study.Item Design of knowledge-based systems for automated deployment of building management services(2020-11) Schneider, Georg F.; Kontes, Georgios D.; Qiu, Haonan; Silva, Filipe J.; Bucur, Mircea; Malanik, Jakub; Schindler, Zdenek; Andriopolous, Panos; de Agustin-Camacho, Pablo; Romero-Amorrortu, Ander; Grün, Gunnar; Tecnalia Research & Innovation; LABORATORIO DE TRANSFORMACIÓN URBANA; EDIFICACIÓN DE ENERGÍA POSITIVADespite its high potential, the building's sector lags behind in reducing its energy demand. Tremendous savings can be achieved by deploying building management services during operation, however, the manual deployment of these services needs to be undertaken by experts and it is a tedious, time and cost consuming task. It requires detailed expert knowledge to match the diverse requirements of services with the present constellation of envelope, equipment and automation system in a target building. To enable the widespread deployment of these services, this knowledge-intensive task needs to be automated. Knowledge-based methods solve this task, however, their widespread adoption is hampered and solutions proposed in the past do not stick to basic principles of state of the art knowledge engineering methods. To fill this gap we present a novel methodological approach for the design of knowledge-based systems for the automated deployment of building management services. The approach covers the essential steps and best practices: (1) representation of terminological knowledge of a building and its systems based on well-established knowledge engineering methods; (2) representation and capturing of assertional knowledge on a real building portfolio based on open standards; and (3) use of the acquired knowledge for the automated deployment of building management services to increase the energy efficiency of buildings during operation. We validate the methodological approach by deploying it in a real-world large-scale European pilot on a diverse portfolio of buildings and a novel set of building management services. In addition, a novel ontology, which reuses and extends existing ontologies is presented.Item The deterioration and environmental impact of binary cements containing thermally activated coal mining waste due to calcium leaching(2018-05-10) Arribas, I.; Vegas, I.; García, V.; Vigil de la Villa, R.; Martínez-Ramírez, S.; Frías, M.; TRAZABILIDAD CIRCULAR; GENERALCalcium-leaching processes can potentially degrade the structure of a concrete matrix. This problem is studied here through the progressive dissolution of Ca2+ in both ordinary Portland cement pastes (C-0) and binary cement blends (C-20) containing 20% thermally Activated Coal Mining Waste (ACMW).1 A series of accelerated tests are conducted that involve the immersion of these cement pastes in a 6 M ammonium nitrate solution at a temperature of 20 C for 7 and for 21 days. A rise in paste porosity was observed, due to increased capillary pore sizes of between 5 and 0.1 μm. In the case of the 20% ACMW pastes (C-20), calcium leaching decreased, probably as a consequence of the pozzolanic effect of the ACMW, while potassium and magnesium leaching increased, due to the presence of the phyllosilicates in the ACMW. The paste compounds most affected by leaching were Ca(OH)2, C6AS3H32, and C4AC¯H12. In general terms, it can be concluded that the incorporation of ACMW into binary cements slightly reduces the calcium leaching phenomena. Concerning the environmental impact assessment, the substitution of 20% OPC by ACMW reduced CO2 emissions by as much as 12% and improved energy efficiency by using approximately 19% fewer fossil resources.Item Development of ultra-high performance concretes with self-healing micro/nano-additions(2017-05-01) García Calvo, J. L.; Pérez, G.; Carballosa, P.; Erkizia, E.; Gaitero, J. J.; Guerrero, A.; Gerrero, A.; ECOEFICIENCIA DE PRODUCTOS DE CONSTRUCCIÓN; Tecnalia Research & InnovationUHPC are developed in present paper incorporating an innovative self-healing system based on two micro/nano-additions: silica microcapsules containing epoxy sealing compound (CAP) and amine functionalised silica nanoparticles. Although CAP are well integrated within the cementitious matrix, their inclusion promotes a reduction in the mechanical performance so CAP could act as weak points. However, the inclusion of these additions refines pore distribution thus increasing the expected durability in aggressive media. An effective autonomous self-healing capacity is assessed/confirmed which is unexpectedly higher in the concretes with the lower healing additions content studied. This capacity depends on the crack width and the healing period considered.