This page has only limited features, please log in for full access.
The application of materials with high moisture storage capacity close to the interior surface presents a prospective passive method for improving indoor relative humidity conditions. In this paper, lime-cement plasters containing three different types of superabsorbent polymers (SAPs) in varying dosages are introduced and their mechanical, hygric, and thermal characteristics are analyzed in a relation to microstructure. The experimental results show a significant effect of both SAP amount and chemical composition on all functional properties of studied plasters. The incorporation of 1.5% of SAP may induce up to 2.5 better moisture buffering, thus significantly improving the passive humidity control capability. Considering overall functional parameters of SAP-modified plasters, the dosage of 1 wt.% can thus be viewed as a rational compromise between the moisture storage capability and mechanical properties. The obtained wide sets of parameters can be utilized directly as input data of computational models suitable for the assessment of the interior microclimate of residential and administrative buildings.
Jan Fořt; Magdaléna Doleželová; Václav Kočí; Robert Černý. Functional Properties of SAP-Based Humidity Control Plasters. Polymers 2021, 13, 2279 .
AMA StyleJan Fořt, Magdaléna Doleželová, Václav Kočí, Robert Černý. Functional Properties of SAP-Based Humidity Control Plasters. Polymers. 2021; 13 (14):2279.
Chicago/Turabian StyleJan Fořt; Magdaléna Doleželová; Václav Kočí; Robert Černý. 2021. "Functional Properties of SAP-Based Humidity Control Plasters." Polymers 13, no. 14: 2279.
Plaster has, from ancient times, been used as a decorative material. However, the advances in materials engineering such as thermal and moisture control provide new opportunities. Superabsorbent polymers (SAPs) have been found to possess passive moisture control that may find utilization in modern buildings. However, the main drawback is associated with a limited number of applicable SAPs due to mechanical strength loss. In this regard, concurrent utilization of cellulose fibers may provide additional benefits linked with the reinforcing of plaster structure and preservation of superior hygric properties. In this regard, this study investigates the combined effect of SAP and cellulose fibers on the material properties of cement-lime plaster in terms of its mechanic, thermal, and hygric properties. To access the capability of such modified plasters to control the interior moisture fluctuations, the moisture buffering value is determined. Obtained results show the effect of both applied admixtures on material performance, whilst the synergic effect was most obvious for humidity control accessed through the moisture buffer coefficient.
Jan Fořt; Jiří Šál; Jaroslav Žák. Combined Effect of Superabsorbent Polymers and Cellulose Fibers on Functional Performance of Plasters. Energies 2021, 14, 3679 .
AMA StyleJan Fořt, Jiří Šál, Jaroslav Žák. Combined Effect of Superabsorbent Polymers and Cellulose Fibers on Functional Performance of Plasters. Energies. 2021; 14 (12):3679.
Chicago/Turabian StyleJan Fořt; Jiří Šál; Jaroslav Žák. 2021. "Combined Effect of Superabsorbent Polymers and Cellulose Fibers on Functional Performance of Plasters." Energies 14, no. 12: 3679.
Ambient comfort maintenance accompanied by excessive energy consumption is hugely criticized concerning the limited sustainability of the building sector in the long-term. In this sense, the energy reduction strategies based on the employment of passive air-control techniques are viewed as a prospective solution for improved energy performance. In order to contribute to this significant issue, this paper is aimed at the design and material characterization of novel plaster with an improved thermal and humidity control performance. For this purpose, a form-stable diatomite/dodecanol-based phase change material together with superabsorbent polymer are used as admixtures for the passive moderation of indoor air quality by newly designed modified plasters. The experimental assessment of the functional properties by means of mechanical strength, thermal conductivity, and hygric properties is performed. Considering the goal of the paper, particular attention is paid to the characterization of water vapor storage and moisture buffering according to the Nordtest method. Differential scanning calorimetry is employed for the description of phase change intervals as well as the specific enthalpy of phase change. The obtained results point to significant improvements in the hygroscopic performance and increased thermal energy storage that can be used for passive moderation of the indoor temperature and reduction of the relative humidity swings.
Jan Fořt; Jan Kočí; Jaroslav Pokorný; Luboš Podolka; Michal Kraus; Robert Černý. Characterization of Responsive Plasters for Passive Moisture and Temperature Control. Applied Sciences 2020, 10, 9116 .
AMA StyleJan Fořt, Jan Kočí, Jaroslav Pokorný, Luboš Podolka, Michal Kraus, Robert Černý. Characterization of Responsive Plasters for Passive Moisture and Temperature Control. Applied Sciences. 2020; 10 (24):9116.
Chicago/Turabian StyleJan Fořt; Jan Kočí; Jaroslav Pokorný; Luboš Podolka; Michal Kraus; Robert Černý. 2020. "Characterization of Responsive Plasters for Passive Moisture and Temperature Control." Applied Sciences 10, no. 24: 9116.
The functional properties of composites modified by superabsorbent polymers (SAPs) strongly depend on the swelling capacity of applied SAPs. In this sense, three types of commercially available SAPs namely Cablock CT, Hydropam, and Creasorb SIS with different chemical composition and particle size distribution were studied in this manuscript to reveal the differences in absorptivity as can be viewed as pretests for their utilization in concrete composites. In addition, absorptivity in distilled water, tap water, and 0.1 M NaCl solution are examined for determining the SAPs response for the change of the solution pH. To overcome problems with the teabag method inaccuracy, the new method is introduced. Besides to quantitative evaluation of the SAPs absorptivity, the correlation for the absorption and desorption period as the function of SAPs residence time within the examined solution is proposed. To access the effect of selected SAPs on functional properties, optimization based on the flow table test is employed and mechanical parameters are determined after 7, 14, 28, and 90 days of curing. Obtained results refer to substantial differences between particular SAPs and contribute to the understanding of the effect of SAP on the functional properties of cement-based materials.
Jan Fořt; Przemysław Migas; Robert Černý. Effect of Absorptivity of Superabsorbent Polymers on Design of Cement Mortars. Materials 2020, 13, 5503 .
AMA StyleJan Fořt, Przemysław Migas, Robert Černý. Effect of Absorptivity of Superabsorbent Polymers on Design of Cement Mortars. Materials. 2020; 13 (23):5503.
Chicago/Turabian StyleJan Fořt; Przemysław Migas; Robert Černý. 2020. "Effect of Absorptivity of Superabsorbent Polymers on Design of Cement Mortars." Materials 13, no. 23: 5503.
The abandonment of coal energy plants in the near future will result in a substantially reduced availability of the coal fly ash broadly used as an efficient supplementary material. In line with the growth of alternative and renewable energy resources, the amount of biomass-based ash rises substantially. Nevertheless, a diverse chemical composition prevents a broader utilization of biomass-based fly ash compared to coal ash on an industrial scale. On this account, the present work is aimed at investigating the basic physical and mechanical properties of concrete mortars modified by a high volume of biomass fly ash (BFA) from wood combustion. Delivered results confirm a significant potential of BFA in the building industry. Experimental analysis of concrete mortars with BFA reveals preservation or even improvement of compressive and bending strength up to 30 wt.% cement replacement. On the contrary, higher dosages induce a gradual decrease in mechanical performance. The performed Life Cycle Assessment analysis reveals the perspective of BFA incorporation taking into account environmental issues considering the ratio between preservation of mechanical performance per normalized endpoint environmental score that allows a direct comparison with other alternatives.
Jan Fořt; Jiří Šál; Jaroslav Žák; Robert Černý. Assessment of Wood-Based Fly Ash as Alternative Cement Replacement. Sustainability 2020, 12, 9580 .
AMA StyleJan Fořt, Jiří Šál, Jaroslav Žák, Robert Černý. Assessment of Wood-Based Fly Ash as Alternative Cement Replacement. Sustainability. 2020; 12 (22):9580.
Chicago/Turabian StyleJan Fořt; Jiří Šál; Jaroslav Žák; Robert Černý. 2020. "Assessment of Wood-Based Fly Ash as Alternative Cement Replacement." Sustainability 12, no. 22: 9580.
The tightening of environmental standards in the EU including the presupposed abatement of coal combustion power plants presents an important impulse towards the transition to a circular economy. However, the achievement of this challenging goal requires a solution to a number of problems. One of the downstream problems consists in the fact that the application of fly ash originating in coal combustion (CFA) as a partial cement replacement might be gradually abandoned in future decades. The first reason may be economical as the increasing environmental regulations will probably result in its more costly processing. The second one is related to the increasing use of alternative energy sources which can lead to the decreasing availability of CFA. Biomass fly ash (BFA) originating from wood combustion can be considered as one of the prospective environmentally more friendly candidates for a partial replacement of CFA as supplementary cementitious material (SCM). In this paper, functional aspects of a possible replacement of CFA by BFA in blended cements are analyzed. Complex characterization of BFA performed prior to the other investigations reveals very good prerequisites for its use as SCM. The experimental analysis of functional properties of Portland cement-BFA based composites after 28-days curing shows the suitability of BFA as SCM for the cement replacement up to 30% by mass. The data collected after 90 and 180 days of curing indicate a substantial improvement of strength of all analyzed composites. The significantly lower content of hazardous elements in BFA in a comparison with CFA presents another benefit; it can be used in blended cements without any further processing or treatment.
Jan Fořt; Jiří Šál; Radek Ševčík; Magdaléna Doleželová; Martin Keppert; Miloš Jerman; Martina Záleská; Vojtěch Stehel; Robert Černý. Biomass fly ash as an alternative to coal fly ash in blended cements: Functional aspects. Construction and Building Materials 2020, 271, 121544 .
AMA StyleJan Fořt, Jiří Šál, Radek Ševčík, Magdaléna Doleželová, Martin Keppert, Miloš Jerman, Martina Záleská, Vojtěch Stehel, Robert Černý. Biomass fly ash as an alternative to coal fly ash in blended cements: Functional aspects. Construction and Building Materials. 2020; 271 ():121544.
Chicago/Turabian StyleJan Fořt; Jiří Šál; Radek Ševčík; Magdaléna Doleželová; Martin Keppert; Miloš Jerman; Martina Záleská; Vojtěch Stehel; Robert Černý. 2020. "Biomass fly ash as an alternative to coal fly ash in blended cements: Functional aspects." Construction and Building Materials 271, no. : 121544.
The extensive exploitation of natural resources, together with an inefficient use of end-of-life materials, results in the generation of vast amounts of waste. The current material streams are to be reconsidered to mitigate the environmental burdens and achieve the sustainability goals. However, these intentions usually lead to material downcycling, which does not provide significant environmental benefits. In this paper, the potential of waste brick recycling is assessed from the environmental point of view as the recycling options of waste bricks attract an eminent attention due to rationalization and optimization of material streams, including transformation to the circular economy model according to the EU commitments. Three different scenarios are taken into account in that respect: replacement of natural aggregate, partial replacement of cement binder, and alkaline activation. The life cycle methodology is used at the assessment and the obtained results are presented on both midpoint and endpoint levels. The analysis of environmental impacts shows only minor improvements resulting from the replacement of natural aggregates by recycled waste bricks. The partial replacement of cement by waste bricks in powdered form can provide the most substantial benefits including decarbonization of the construction sector. The application of alkaline activators can harm the potential of alkali-activated materials considerably due to their negative effects on human health. A complex assessment of recycling scenarios is found to preferable to one-sided analyses aimed at carbon dioxide emission reduction only if a real sustainability without any hidden risks is to be achieved.
Jan Fořt; Robert Černý. Transition to circular economy in the construction industry: Environmental aspects of waste brick recycling scenarios. Waste Management 2020, 118, 510 -520.
AMA StyleJan Fořt, Robert Černý. Transition to circular economy in the construction industry: Environmental aspects of waste brick recycling scenarios. Waste Management. 2020; 118 ():510-520.
Chicago/Turabian StyleJan Fořt; Robert Černý. 2020. "Transition to circular economy in the construction industry: Environmental aspects of waste brick recycling scenarios." Waste Management 118, no. : 510-520.
The level of indoor humidity has to meet several criteria according to the preservation of a healthy indoor climate for building inhabitants. On top of that, the undesired moisture content is associated with a proliferation of various organisms which results in an adverse effect on the durability of building materials. Facing the impact of climate change and excessive energy consumption associated with building maintenance, the employment of passive moderation techniques takes place to avoid the usage of energy-demanding HVAC devices. The application of advanced materials such as superabsorbent polymers (SAPs), commonly used in diapers or other hygiene products, can bring a very effective solution for this issue overcoming. In this paper, the effect of 0.5; 0.1 and 1.5 wt.% dosages of SAPs incorporated into a cement-lime plaster are studied to evaluate the material performance in the sense of moisture moderation. First, the basic material properties, moisture transport and storage properties, thermal conductivity and specific heat capacity are determined to access the influence of SAP admixtures on the functional performance of studied plasters. Consequently, the experimentally accessed results are further employed for the computational modeling analysis which evaluates the capability of studied plasters for the moderation of moisture content in constructions.
Jan Fořt; Petr Hotěk; Jan Kočí; Robert Černý. Utilization plasters with superabsorbent admixture to moderate moisture level in constructions. E3S Web of Conferences 2020, 172, 11009 .
AMA StyleJan Fořt, Petr Hotěk, Jan Kočí, Robert Černý. Utilization plasters with superabsorbent admixture to moderate moisture level in constructions. E3S Web of Conferences. 2020; 172 ():11009.
Chicago/Turabian StyleJan Fořt; Petr Hotěk; Jan Kočí; Robert Černý. 2020. "Utilization plasters with superabsorbent admixture to moderate moisture level in constructions." E3S Web of Conferences 172, no. : 11009.
Moisture loads in building interiors are accompanied by a deterioration of the indoor air quality. Such a phenomenon may induce serious health risks for building inhabitants as well as degradation of furnishing. Unfortunately, the employment of additional heat, ventilation and air conditioning (HVAC) devices does not comply with the sustainability principle due to increased energy consumption, thus cannot be viewed as an efficient solution. This study deals with the use of superabsorbent polymers (SAP) in cement-lime plasters, thus extends the current state of knowledge and outlines further possible development of novel moisture responsive plasters since lightweight aggregates do not provide the desired performance. To be specific, this paper contemplates the experimental analysis of novel plasters modified by 0.5, 1 and 1.5 wt. % of SAP to obtain input parameters for computational modeling. Based on the obtained outputs, the incorporation of SAP admixture resulted in a substantial increase in moisture transport properties including the water absorption coefficient and water vapor diffusion properties. The performed computational modeling revealed a considerable reduction of relative humidity fluctuations, thus mitigation of potential health issues associated with undesired moisture content in building interiors. Achieved results indicate that the SAP enhanced plasters have substantial passive moisture buffering performance and thus may contribute to the improvement of indoor air quality.
Jan Fořt; Jan Kočí; Jaroslav Pokorný; Robert Černý. Influence of Superabsorbent Polymers on Moisture Control in Building Interiors. Energies 2020, 13, 2009 .
AMA StyleJan Fořt, Jan Kočí, Jaroslav Pokorný, Robert Černý. Influence of Superabsorbent Polymers on Moisture Control in Building Interiors. Energies. 2020; 13 (8):2009.
Chicago/Turabian StyleJan Fořt; Jan Kočí; Jaroslav Pokorný; Robert Černý. 2020. "Influence of Superabsorbent Polymers on Moisture Control in Building Interiors." Energies 13, no. 8: 2009.
Facing the consequences of climate change and fuel price rises, the achievement of the requirements for low-energy consumption of buildings has become a challenging issue. On top of that, increased demands on indoor hygrothermal conditions usually require the utilization of additional heating, ventilation, and air-conditioning (HVAC) systems to maintain a comfortable environment. On this account, several advanced and modern materials are widely investigated as a promising way for reduction of the buildings’ energy consumption including utilization of passive heating/cooling energy. However, the efficiency and suitability of passive strategies depending on several aspects including the influence of location, exterior climatic conditions, load-bearing materials used, and insulation materials applied. The main objective of this study consists of the investigation of the energy performance benefits gained by the utilization of advanced materials in plasters by computational modeling. Results obtained from a computational simulation reveal the capability of the studied passive cooling/heating methods on the moderation of indoor air quality together with the reduction of the diurnal temperature fluctuation. Achieved results disclose differences in terms of energy savings for even small variation in outdoor climate conditions. Additionally, the effectivity of passive cooling/heating alters considerably during the summer and winter periods. Based on the analysis of simulated heat fluxes, the potential energy savings related to improved thermal properties of the applied plaster layer reached up to 12.08% and thus represent an interesting passive solution towards energy sustainability to meet the criteria on modern buildings.
Jan Fořt; Jiří Šál; Jan Kočí; Robert Černý. Energy Efficiency of Novel Interior Surface Layer with Improved Thermal Characteristics and Its Effect on Hygrothermal Performance of Contemporary Building Envelopes. Energies 2020, 13, 2012 .
AMA StyleJan Fořt, Jiří Šál, Jan Kočí, Robert Černý. Energy Efficiency of Novel Interior Surface Layer with Improved Thermal Characteristics and Its Effect on Hygrothermal Performance of Contemporary Building Envelopes. Energies. 2020; 13 (8):2012.
Chicago/Turabian StyleJan Fořt; Jiří Šál; Jan Kočí; Robert Černý. 2020. "Energy Efficiency of Novel Interior Surface Layer with Improved Thermal Characteristics and Its Effect on Hygrothermal Performance of Contemporary Building Envelopes." Energies 13, no. 8: 2012.
Measurements of quantities by differential scanning calorimetry (DSC) are influenced by intrinsic factors given by the construction limits of particular DSC devices. The position of temperature sensors outside the samples causes the produced experimental outputs to suffer from signal delay or partial signal consumption. Differences in sample mass and heating rate belong to other typical sources of errors which cannot be fully eliminated even by the experimental calibration. In this paper, a computational method involving detailed modeling of thermal phenomena in the calorimeter-sample system is used for the correction of inaccuracies in DSC measurements. The applied model is able to extract pure data related to the sample itself that is free of distortion. In a practical application of the method, lime hydrate samples of various mass are analyzed at first experimentally while several different heating rates are used, and the influence of varying parameters on the obtained outputs is recorded. The experimental data are then reconstructed using computational modeling of thermal phenomena in the calorimeter-sample system. The corrected specific heat power values are found to be up to 9% higher and can be attributed to the heat capacity of inner parts of the device that consume a part of the heat. The highest agreement between experimental and computational outputs is achieved when a sample filling one half of the crucible’s volume is heated at 7 K·min-1. Such a parameter choice shows a low temperature shift (<5 °C) and the specific heat power difference is only 0.09 mW·mg-1 (3.4 %).
Vaclav Koci; Jan Fort; Jiri Madera; Lenka Scheinherrova; Anton Trnik; Robert Cerny. Correction of Errors in DSC Measurements Using Detailed Modeling of Thermal Phenomena in Calorimeter-Sample System. IEEE Transactions on Instrumentation and Measurement 2020, 69, 8178 -8186.
AMA StyleVaclav Koci, Jan Fort, Jiri Madera, Lenka Scheinherrova, Anton Trnik, Robert Cerny. Correction of Errors in DSC Measurements Using Detailed Modeling of Thermal Phenomena in Calorimeter-Sample System. IEEE Transactions on Instrumentation and Measurement. 2020; 69 (10):8178-8186.
Chicago/Turabian StyleVaclav Koci; Jan Fort; Jiri Madera; Lenka Scheinherrova; Anton Trnik; Robert Cerny. 2020. "Correction of Errors in DSC Measurements Using Detailed Modeling of Thermal Phenomena in Calorimeter-Sample System." IEEE Transactions on Instrumentation and Measurement 69, no. 10: 8178-8186.
Geopolymerization of waste products can contribute to the solution of current environmental issues related to depletion of natural resources. In this paper, several geopolymer mixes are prepared using waste brick in powdered form, while different alkaline activators and curing conditions are applied. Experimental results show that the reaction rate at early age decreases with the increasing silicate modulus as well as with the rise of curing temperature; the reaction is though significantly slower than, e.g., for metakaolin-based geopolymers because of the low content of amorphous phase in the brick. The most compact microstructure is observed for geopolymers with highest reaction rate at early age; with increasing silicate modulus of the activator and decreasing curing temperature the compactness gradually decreases and the specific pore volume increases. Thermal analysis shows a decreasing weight loss with increasing silicate modulus for all temperatures, while dehydration of N-A-S-H and C-A-S-H gels are identified as the most important factors. Dehydroxylation of muscovite is found for the mixtures cured at temperatures up to 60 °C only, and decomposition of calcium carbonate just for 20 °C curing. Most crystalline phases detected by X-ray diffraction analysis in designed geopolymers are identical to those found in the raw precursor, which indicates only a partial geopolymerization and presence of a significant amount of unreacted particles. For geopolymers cured at 60 °C and 80 °C, formation of zeolitic phases is observed. While sodalite and chabazite are found only in mixtures with higher reaction rate, gismondine appears in geopolymers with higher silicate modulus.
Jan Fořt; Radimír Novotný; Eva Vejmelková; Anton Trník; Pavla Rovnaníková; Martin Keppert; Vojtěch Pommer; Robert Černý. Characterization of geopolymers prepared using powdered brick. Journal of Materials Research and Technology 2019, 8, 6253 -6261.
AMA StyleJan Fořt, Radimír Novotný, Eva Vejmelková, Anton Trník, Pavla Rovnaníková, Martin Keppert, Vojtěch Pommer, Robert Černý. Characterization of geopolymers prepared using powdered brick. Journal of Materials Research and Technology. 2019; 8 (6):6253-6261.
Chicago/Turabian StyleJan Fořt; Radimír Novotný; Eva Vejmelková; Anton Trník; Pavla Rovnaníková; Martin Keppert; Vojtěch Pommer; Robert Černý. 2019. "Characterization of geopolymers prepared using powdered brick." Journal of Materials Research and Technology 8, no. 6: 6253-6261.
Concrete despite many performed studies still requires further research on material optimization towards its improvements. On this account the superabsorbent polymers can be viewed as very promising materials with a positive influence on various properties of cementitious materials. The beneficial effect of SAPs on mitigation of autogenous shrinkage or rapid cracks self-healing. However, the absorption capability of SAPs also poses a risk for the formation of dense structure and loss in material durability. The performed study contemplating the influence of two grades of SAP admixtures on mechanical parameters of designed concrete. Obtained results revealed an adverse effect of SAPs on compressive strength. This finding can be assigned to a rapid swelling capability of SAPs, thus a formation of voids in material structure and a significant increase in the total open porosity. Incorporation of about 1.5 wt.% of SAP admixture decreased compressive strength about almost 50% compared to the reference sample.
Jan Fořt; Jiří Maděra; Martin Mildner. Mechanical parameters of cementitious materials with superabsorbent polymer admixture. MATEC Web of Conferences 2019, 282, 02063 .
AMA StyleJan Fořt, Jiří Maděra, Martin Mildner. Mechanical parameters of cementitious materials with superabsorbent polymer admixture. MATEC Web of Conferences. 2019; 282 ():02063.
Chicago/Turabian StyleJan Fořt; Jiří Maděra; Martin Mildner. 2019. "Mechanical parameters of cementitious materials with superabsorbent polymer admixture." MATEC Web of Conferences 282, no. : 02063.
Excessive production of carbon dioxide is viewed as one of the most threat to the current generation. While the industry and transportation sector significantly improve energy efficiency and more actions are awaited, the building sector still lacking similar progress. European member states committed a decrease in produced carbon emissions which emphasis energy retrofitting of current obsolete building stock. The complex assessment of used applied materials poses an important task and searching for an advanced approach is still a big challenge. On this account, the performed study contemplates the monetarization of all negative environmental externalities to support method towards acceptance of solution with long-term perspectives. Considering responsible attitude to environmental issues accompanied by whole service life of used materials. Obtained results revealed environmental costs of mineral wool production as a supporting tool for complex building retrofit assessment.
Jan Fořt; Jiří Maděra; Robert Černý. Monetized environmental assessment of interior thermal insulation. MATEC Web of Conferences 2019, 282, 02106 .
AMA StyleJan Fořt, Jiří Maděra, Robert Černý. Monetized environmental assessment of interior thermal insulation. MATEC Web of Conferences. 2019; 282 ():02106.
Chicago/Turabian StyleJan Fořt; Jiří Maděra; Robert Černý. 2019. "Monetized environmental assessment of interior thermal insulation." MATEC Web of Conferences 282, no. : 02106.
Thermal energy storage systems based on latent heat utilization represent a promising way to achieve building sustainability and energy efficiency. The application of phase change materials (PCMs) can substantially improve the thermal performance of building envelopes, decrease the energy consumption, and support the thermal comfort maintenance, especially during peak periods. On this account, the newly formed form-stable PCM (FSPCM) based on diatomite impregnated by dodecanol is used as an admixture for design of interior plasters with enhanced thermal storage capability. In this study, the effect of FSPCM admixture on functional properties of plasters enriched by 8, 16 and 24 wt.% is determined. On this account, the assessment of physical, thermal, hygric, and mechanical properties is done in order to correlate obtained results with applied FSPCM dosages. Achieved results reveal only a minor influence of applied FSPCM admixture on material properties when compared to negative impacts of commercially produced PCMs. The differential scanning calorimetry discloses variations of the phase change temperature, which ranging from 20.75 °C to 21.68 °C and the effective heat capacity increased up to 15.38 J/g accordingly to the applied FSPCM dosages.
Jan Fořt; Radimír Novotný; Anton Trník; Robert Černý. Preparation and Characterization of Novel Plaster with Improved Thermal Energy Storage Performance. Energies 2019, 12, 3318 .
AMA StyleJan Fořt, Radimír Novotný, Anton Trník, Robert Černý. Preparation and Characterization of Novel Plaster with Improved Thermal Energy Storage Performance. Energies. 2019; 12 (17):3318.
Chicago/Turabian StyleJan Fořt; Radimír Novotný; Anton Trník; Robert Černý. 2019. "Preparation and Characterization of Novel Plaster with Improved Thermal Energy Storage Performance." Energies 12, no. 17: 3318.
The excessive energy consumption by the building sector poses an important task for the energy sustainability. On this account, the European regulatory framework established several strategies in order to reach the EU target for nearly zero-energy new buildings and retrofitting of outdated existing buildings. The application of the thermal insulation panel is perceived as the efficient way towards thermal stability of buildings. From the environmental point of view, an increased thermal performance of buildings is strongly connected with the consumption of fossil fuel and this step represents a significant progress. However, the initial environmental loads accompanied with the production of various thermal insulation materials is usually neglected within these considerations, despite their energy demanding manufacturing. This paper summarizes the environmental burden related to the production of mineral wool as a very often used building insulation material with emphasis on carbon dioxide emissions. Enumerated carbon dioxide emissions related to the material production are helpful for the total environmental assessment of retrofitting of building envelopes.
Jan Fořt; Robert Černý. Environmental assessment of mineral wool manufacturing. AIP Conference Proceedings 2018, 2040, 040008 .
AMA StyleJan Fořt, Robert Černý. Environmental assessment of mineral wool manufacturing. AIP Conference Proceedings. 2018; 2040 (1):040008.
Chicago/Turabian StyleJan Fořt; Robert Černý. 2018. "Environmental assessment of mineral wool manufacturing." AIP Conference Proceedings 2040, no. 1: 040008.
Alkali activated aluminosilicates present a promising way for future advances in materials engineering towards environmental sustainability. In this paper, the mechanical, thermal and hygric properties of aluminosilicates designed using waste brick powder from insulation blocks are investigated. The applied waste material is alkali activated by the mixtures of sodium hydroxide and sodium silicate with the silicate modulus ranging from 0.8 to l.4. The obtained results reveal a significant influence of increased silicate modulus on the properties of analyzed aluminosilicates. The more dense and compact material structure observed for higher silicate moduli leads to an improvement of mechanical properties of designed materials. The thermal and hygric properties are found to be influenced by the occurrence of cracks in the material structure. The experimental results indicate a good potential of alkali activated aluminosilicates for design of new building materials in terms of sustainable development principles.
Eva Vejmelková; Jan Fořt; Aneta Junková; Monika Čáchová; Pavla Rovnanikova; Robert Černý. Thermal and hygric properties of alkali activated aluminosilicates. AIP Conference Proceedings 2018, 2040, 040002 .
AMA StyleEva Vejmelková, Jan Fořt, Aneta Junková, Monika Čáchová, Pavla Rovnanikova, Robert Černý. Thermal and hygric properties of alkali activated aluminosilicates. AIP Conference Proceedings. 2018; 2040 (1):040002.
Chicago/Turabian StyleEva Vejmelková; Jan Fořt; Aneta Junková; Monika Čáchová; Pavla Rovnanikova; Robert Černý. 2018. "Thermal and hygric properties of alkali activated aluminosilicates." AIP Conference Proceedings 2040, no. 1: 040002.
A novel shape-stabilized phase change material (PCM) is prepared as an energy-efficient solution aimed at the improvement of thermal stability of building materials. Dodecanol having a suitable temperature interval of phase transition and high latent heat is selected as the PCM medium. Diatomite powder used as the PCM core material is impregnated by dodecanol using the vacuum impregnation method. The particle size distribution of the prepared PCM is analyzed at first to find the possible agglomeration of particles. A detailed characterization of mutual material compatibility is performed by scanning electron microscopy and Fourier transform infrared spectroscopy. The melting and solidification temperatures of the developed PCM are found at 23.3 °C and 21.2 °C, respectively; the measurement of corresponding latent heats shows 71.4 J·g−1 and 72.6 J·g−1. The incorporation of the novel PCM into cement–lime plaster does not significantly affect its phase change behavior and confirms its good potential for applications in building practice.
Jan Fořt; Anton Trník; Milena Pavlíková; Zbyšek Pavlík; Robert Černý. Fabrication of Dodecanol/Diatomite Shape-Stabilized PCM and Its Utilization in Interior Plaster. International Journal of Thermophysics 2018, 39, 137 .
AMA StyleJan Fořt, Anton Trník, Milena Pavlíková, Zbyšek Pavlík, Robert Černý. Fabrication of Dodecanol/Diatomite Shape-Stabilized PCM and Its Utilization in Interior Plaster. International Journal of Thermophysics. 2018; 39 (12):137.
Chicago/Turabian StyleJan Fořt; Anton Trník; Milena Pavlíková; Zbyšek Pavlík; Robert Černý. 2018. "Fabrication of Dodecanol/Diatomite Shape-Stabilized PCM and Its Utilization in Interior Plaster." International Journal of Thermophysics 39, no. 12: 137.
Energy demands of current buildings present an important problem for building designers and engineers. However, the necessity to retrofit building envelopes and achieve a better thermal performance is substantially limited by the economic viability. Despite of the environmental benefits accompanied with enhanced thermal stability, a complex evaluation of the impact of reconstruction works from various perspectives is still needed. In this paper, a quantification of physical, social, economic, and environmental benefits resulting from the application of exterior thermal insulation system to an institutional building is presented. The temperature profiles in the wall cross-section are used for the assessment of the effect of expanded polystyrene boards. The annual energy consumption and carbon emission production is found to decrease by 46 % as the result of better thermal performance. The improved social comfort is confirmed by the evaluation of predicted mean vote characterizing the average heat sensation of building occupants. The carbon payback of 3.24 years refers to low initial environmental burden in proportion to obtained energy savings. However, full investments recovery rate varying from 43 to 60 years in dependence on applied economic scenarios reaches almost the lifetime of used materials, which presents a substantial barrier despite of the discounted cost savings of 180,000 Euros during the 60-year lifespan.
Jan Fořt; Pavel Beran; Zbyšek Pavlík; Robert Černý. Complex assessment of reconstruction works on an institutional building: A case study. Journal of Cleaner Production 2018, 202, 871 -882.
AMA StyleJan Fořt, Pavel Beran, Zbyšek Pavlík, Robert Černý. Complex assessment of reconstruction works on an institutional building: A case study. Journal of Cleaner Production. 2018; 202 ():871-882.
Chicago/Turabian StyleJan Fořt; Pavel Beran; Zbyšek Pavlík; Robert Černý. 2018. "Complex assessment of reconstruction works on an institutional building: A case study." Journal of Cleaner Production 202, no. : 871-882.
Inverse analysis of experimental accessed moisture profiles is presented in the paper as an effective tool for the determination of moisture diffusivity of hybrid fiber reinforced Ultra High Performance Concrete (UHPC) exposed to high temperatures. The UHPC was provided with fiber reinforcement based on polyvinyl alcohol (PVA) and steel fibers. Analyzed material was characterized by its bulk density, matrix density, and total open porosity. Moisture profiles were measured on prismatic samples in 1-D vertical arrangement of water suction experiment. For moisture content measurement, gravimetric method was used. In order to analyze effect of high-temperature load on concrete performance, all the realized experiments were done for concrete samples exposed to laboratory temperature and to the temperatures of 800 °C and 1000 °C respectively. For calculation of moisture dependent moisture diffusivity, inverse analysis method based on the Boltzmann-Matano treatment was used.
Jan Fořt; Lucie Zemanová; Zbyšek Pavlík; Robert Černý. Inverse analysis of moisture profiles for the assessment of moisture diffusivity of hybrid fiber reinforced UHPC. INTERNATIONAL CONFERENCE OF NUMERICAL ANALYSIS AND APPLIED MATHEMATICS (ICNAAM 2017) 2018, 1978, 250008 .
AMA StyleJan Fořt, Lucie Zemanová, Zbyšek Pavlík, Robert Černý. Inverse analysis of moisture profiles for the assessment of moisture diffusivity of hybrid fiber reinforced UHPC. INTERNATIONAL CONFERENCE OF NUMERICAL ANALYSIS AND APPLIED MATHEMATICS (ICNAAM 2017). 2018; 1978 (1):250008.
Chicago/Turabian StyleJan Fořt; Lucie Zemanová; Zbyšek Pavlík; Robert Černý. 2018. "Inverse analysis of moisture profiles for the assessment of moisture diffusivity of hybrid fiber reinforced UHPC." INTERNATIONAL CONFERENCE OF NUMERICAL ANALYSIS AND APPLIED MATHEMATICS (ICNAAM 2017) 1978, no. 1: 250008.