scholarly journals Smart Materials: Cementitious Mortars and PCM Mechanical and Thermal Characterization

Materials ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4163
Author(s):  
Federico Orsini ◽  
Paola Marrone ◽  
Silvia Santini ◽  
Lorena Sguerri ◽  
Francesco Asdrubali ◽  
...  

Climate change (CC) is predominantly connected to greenhouse gas (GHG) emissions from the construction sector. It is clear how it is necessary to rethink construction materials in order to reduce GHG emissions. Among the various strategies proposed, recent research has investigated the potential of smart materials. This study in particular aims to develop an innovative building component that combines high energy performance with reduced thickness and weight. For this reason, the potential of Phase Change Materials (PCM) in cement-based mixes is investigated, comparing the performance of a traditional mix with two innovative mixes made with the addition of 3% and 7% PCM. This work characterizes the new material, analyzing its mechanical and thermal performance, highlighting how the mix strength decreases as the PCM ratio increases; however, both mixes may be considered suitable for masonry structures and may be classified as M5 and M15. Furthermore, from the analysis of the thermal performance, it emerges that the mix presents good behavior in terms of insulating properties.

Proceedings ◽  
2020 ◽  
Vol 63 (1) ◽  
pp. 41
Author(s):  
Hanae El Fakiri ◽  
Lahoucine Ouhsaine ◽  
Abdelmajid El Bouardi

The thermal dynamic behavior of buildings represents an important aspect of the energy efficiency and thermal comfort of the indoor environment. For this, phase change material (PCM) wallboards integrated into building envelopes play an important role in stabilizing the temperature of the human comfort condition. This article provides an assessment of the thermal behavior of a “bi-zone” building cell, which was built based on high-energy performance (HEP) standards and heated by a solar water heater system through a hydronic circuit. The current study is based on studying the dynamic thermal behavior, with and without implantation of PCMs on envelope structure, using a simplified modeling approach. The evolution of the average air temperature was first evaluated as a major indicator of thermal comfort. Then, an evaluation of the thermal behavior’s dynamic profile was carried out in this study, which allowed for the determination of the PCM rate anticipation in the thermal comfort of the building cell.


Buildings ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 6
Author(s):  
Daniel Satola ◽  
Martin Röck ◽  
Aoife Houlihan-Wiberg ◽  
Arild Gustavsen

Improving the environmental life cycle performance of buildings by focusing on the reduction of greenhouse gas (GHG) emissions along the building life cycle is considered a crucial step in achieving global climate targets. This paper provides a systematic review and analysis of 75 residential case studies in humid subtropical and tropical climates. The study investigates GHG emissions across the building life cycle, i.e., it analyses both embodied and operational GHG emissions. Furthermore, the influence of various parameters, such as building location, typology, construction materials and energy performance, as well as methodological aspects are investigated. Through comparative analysis, the study identifies promising design strategies for reducing life cycle-related GHG emissions of buildings operating in subtropical and tropical climate zones. The results show that life cycle GHG emissions in the analysed studies are mostly dominated by operational emissions and are the highest for energy-intensive multi-family buildings. Buildings following low or net-zero energy performance targets show potential reductions of 50–80% for total life cycle GHG emissions, compared to buildings with conventional energy performance. Implementation of on-site photovoltaic (PV) systems provides the highest reduction potential for both operational and total life cycle GHG emissions, with potential reductions of 92% to 100% and 48% to 66%, respectively. Strategies related to increased use of timber and other bio-based materials present the highest potential for reduction of embodied GHG emissions, with reductions of 9% to 73%.


Buildings ◽  
2019 ◽  
Vol 9 (2) ◽  
pp. 49 ◽  
Author(s):  
Lars Gullbrekken ◽  
Steinar Grynning ◽  
Jørn Gaarder

Buildings that are designed to meet high-energy performance requirements, e.g., passive houses, require well-insulated building envelopes, with increased insulation thicknesses for roof, wall and floor structures. We investigate whether there are differences in the efficiency of thermal insulation materials at different moisture levels in the insulation and if there is a larger or smaller risk of natural convection in wood-fibre based insulation than in mineral wool. The work has mainly been performed by use of laboratory measurements included permeability properties and full-scale measurements of thermal transmittance of mineral wool and wood-fibre insulated constructions. In addition, calculations have been used to calculate resulting effects on the thermal performance of constructions. Results showed that the thermal conductivity was unaffected by moisture in the hygroscopic range. The air permeability was found to be approximately 50% higher for the wood-fibre insulation compared to mineral wool insulation. Measurements showed that the largest U-values and Nusselt numbers were found for the wall configuration. Calculation of the U-value of walls showed that in order to achieve the same U-value for the wood-fibre insulated wall as the mineral wool, it is necessary to add 20 mm insulation to the 250 mm wall and approximately 30 mm for the 400 mm wall.


2021 ◽  
Vol 3 (2) ◽  
pp. 173-182
Author(s):  
Javier Ascanio Villabona ◽  
Jon Terés Zubiaga ◽  
Yesid Alfonso Muñoz Maldonado ◽  
Omar Lengerke Pérez ◽  
Luis Alfonso Del Portillo Valdés

In this article, we present the results of the evaluation of the thermal performance of a conventional home in a dry warm climate, a case study in Bucaramanga, Colombia. This simulation, evaluation, and analysis make it necessary since currently in the case study area there is no thermal assessment of the dwellings, which are old houses built with resistive and mechanical analyses, but without regard to thermal behavior or thermal housing comfort. This evaluation is done by means of software simulation. Thus, a valid simulation identifies the weather data present in a dry warm climate zone and determines the geographical location and behavior in the solar diagram. Likewise, the thermal characterization of the soil and the construction materials of support and envelopes of the architecture is performed, to establish its thermal transmittance, thermal resistance, and thermal capacity. As a result of the research, the thermal behavior of the house is presented by means of the calculations made that determine the thermal behavior of the envelopes, energy load balancing, and housing thermal comfort based on the ASHRAE 55 standard by Fanger's method. Consequently, with the above, the results of the simulation and a detailed analysis of the recorded data are presented in the document.


Author(s):  
Etienne MALBILA ◽  
Fati ZOMA ◽  
David Y. K. TOGUYENI ◽  
Chris-veenem Methushael COMPAORE ◽  
Dieudonné Joseph BATHIEBO

This paper deals with building envelope thermal performance through a comparative study of the use of two types of construction materials, such as CEB and cement blocks, in order to introduce the use of double walls in sustainable buildings' construction. The building envelope participates in providing thermal comfort to users and in the optimal management of building energy consumption. This study begins with a survey of public preferences for building materials used in Burkina Faso. The results indicate that 76% of the people surveyed opt for cement blocks over local materials.  Concerning the thermal and specific energy performance, three variants of building envelope were studied: CEB walls, cement blocks and the double-wall (CEB + Cement blocks). It appears that the CEB walls are more efficient than the cement block walls. The introduction of double envelopes leads to the thermal resistance of 357.37m².K/W and reduces the heat flow from 85.32% to 90.24% compared to the wall made with CEB and cement blocks. This approach, which consists in mixing construction materials for good thermal insulation, allows improving the envelope thermal performance and the overall building energy performance.


Author(s):  
Vlatka Rajčić

Façade elements are a building component that satisfies multiple performance parameters. Among other things, “advanced façades” take advantage of hybrid solutions, such as assembling laminated materials. In addition to the enhanced mechanical properties that are typical of optimally composed hybrid structural components, these systems are energy-efficient, durable, and offer lighting comfort and optimal thermal performance, an example of which is the structural solution developed in collaboration with the University of Zagreb and the University of Ljubljana within the Croatian Science Foundation VETROLIGNUM project. The design concept involves the mechanical interaction of timber and glass load-bearing members without sealing or bonding the glass-to-timber surfaces. Following earlier research efforts devoted to the structural analysis and optimization of thus-assembled hybrid Cross-Laminated Timber (CLT)-glass façade elements, in this paper, special focus is given to a thermal and energy performance investigation under ordinary operational conditions. A simplified numerical model representative of a full-size building is first presented by taking advantage of continuous ambient records from a Live-Lab mock-up facility in Zagreb. Afterwards, a more detailed Finite Element (FE) numerical analysis is carried out at the component level to further explore the potential of CLT–glass façade elements. The collected numerical results show that CLT–glass composite panels can offer stable and promising thermal performance for façades similar to national and European standard requirements.


Energies ◽  
2019 ◽  
Vol 12 (12) ◽  
pp. 2373 ◽  
Author(s):  
Ioannis Atsonios ◽  
Ioannis Mandilaras ◽  
Maria Founti

Advanced building envelopes targeting high energy performance should combine high thermal performance with easy and fast installation. The combination of lightweight steel-framed building systems with vacuum insulation panels (VIPs) form an attractive solution toward this requirement. In the present study, a lightweight metal frame drywall building insulated with VIPs is constructed and experimentally/theoretically investigated, focusing on the impact of every type of thermal bridges on the thermal performance of the envelope and its upgrade due to the presence of the VIPs at the walls. Temperature measurements obtained at several locations of the envelope, over a period of one year, are presented and analyzed. The results are in agreement with the theoretical values and demonstrate that the VIPs can reduce the thermal transmittance of the central part of the wall by ca. 50%, limiting the impact of metal studs. The paper discusses the impact of dimensional inaccuracies and damaged panels on the thermal performance of the envelope. It is shown that VIP decreases the impact of thermal bridges and reduces the risk of condensation inside the walls.


Energies ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 3311
Author(s):  
Víctor Pérez-Andreu ◽  
Carolina Aparicio-Fernández ◽  
José-Luis Vivancos ◽  
Javier Cárcel-Carrasco

The number of buildings renovated following the introduction of European energy-efficiency policy represents a small number of buildings in Spain. So, the main Spanish building stock needs an urgent energy renovation. Using passive strategies is essential, and thermal characterization and predictive tests of the energy-efficiency improvements achieving acceptable levels of comfort for their users are urgently necessary. This study analyzes the energy performance and thermal comfort of the users in a typical Mediterranean dwelling house. A transient simulation has been used to acquire the scope of Spanish standards for its energy rehabilitation, taking into account standard comfort conditions. The work is based on thermal monitoring of the building and a numerical validated model developed in TRNSYS. Energy demands for different models have been calculated considering different passive constructive measures combined with real wind site conditions and the behavior of users related to natural ventilation. This methodology has given us the necessary information to decide the best solution in relation to energy demand and facility of implementation. The thermal comfort for different models is not directly related to energy demand and has allowed checking when and where the measures need to be done.


2021 ◽  
Vol 13 (13) ◽  
pp. 7025
Author(s):  
Shiva Gorjian ◽  
Behnam Hosseingholilou ◽  
Laxmikant D. Jathar ◽  
Haniyeh Samadi ◽  
Samiran Samanta ◽  
...  

The food industry is responsible for supplying the food demand of the ever-increasing global population. The food chain is one of the major contributors to greenhouse gas (GHG) emissions, and global food waste accounts for one-third of produced food. A solution to this problem is preserving crops, vegetables, and fruits with the help of an ancient method of sun drying. For drying agricultural and marine products, several types of dryers are also being developed. However, they require a large amount of energy supplied conventionally from pollutant energy sources. The environmental concerns and depletion risks of fossil fuels persuade researchers and developers to seek alternative solutions. To perform drying applications, sustainable solar power may be effective because it is highly accessible in most regions of the world. Greenhouse dryers (GHDs) are simple facilities that can provide large capacities for drying agricultural products. This study reviews the integration of GHDs with different solar technologies, including photovoltaic (PV), photovoltaic-thermal (PVT), and solar thermal collectors. Additionally, the integration of solar-assisted greenhouse dryers (SGHDs) with heat pumps and thermal energy storage (TES) units, as well as their hybrid configuration considering integration with other renewable energy sources, is investigated to improve their thermal performance. In this regard, this review presents and discusses the most recent advances in this field. Additionally, the economic analysis of SGHDs is presented as a key factor to make these sustainable facilities commercially available.


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