Giedrius Balciunas - Academia.edu (original) (raw)

Papers by Giedrius Balciunas

Research paper thumbnail of Physical Properties of Building Blocks from Hemp Shives Aggregate and Cementitious Binder, Manufactured in the Expanded Clay (Vibro Pressing) Production Line

Materials Science Forum

Scientific literature mostly aims at investigation of composites with fibre hemp shives (FHS) agg... more Scientific literature mostly aims at investigation of composites with fibre hemp shives (FHS) aggregate and lime binder, although, such materials are characterised by pretty low mechanical properties. In order to obtain higher mechanical properties of a composite, it is appropriate to use cementitious binder. This work investigates physical properties of blocks from hemp shives aggregate and cementitious binder, manufactured in the expanded clay production line using vibro pressing technology. Following properties of the blocks are determined: freeze-thaw resistance, compressive strength, thermal conductivity and density. Thermal resistance according to EN ISO 6946 for the block with cavities is calculated as well. It is found that compressive strength of FHS-cement blocks may be up to 3.18 MPa when the density is of ~850 kg/m3 and thermal conductivity up to 0.135 W/(m∙K). It is found as well that the decrease of compressive strength is 8.7% after 25 freeze-thaw cycles.

Research paper thumbnail of Performance Analysis of Loose-Fill Thermal Insulation from Wood Scobs Coated with Liquid Glass, Tung Oil, and Expandable Graphite Mixture

Materials

The current study presents the results of monitoring the behavior of loose-fill thermal insulatin... more The current study presents the results of monitoring the behavior of loose-fill thermal insulating material for buildings made of wood scobs (WS), which were coated with one, two, and three component-based coatings from liquid glass (LG), tung oil (TO), and expandable graphite (EG). The thermal conductivity of samples in the dry state and under normal laboratory conditions, short-term water absorption by partial immersion, surface wettability, and water vapor permeability were evaluated, and regression equations describing the variations in numerical values of specified properties under different amounts of each coating component were presented. It was shown that LG and TO act as hydrophobic layers that, in conjunction, reduce water absorption by a maximum of 274%, have a contact angle equal to 86°, and lower thermal conductivity by 55% in the dry state due to the specifics of the layer formed on the surface of WS. The addition of EG to LG coating resulted in insignificantly changed...

Research paper thumbnail of Brushite mineralised Scots pine (Pinus sylvestris L.) sapwood – revealing mineral crystallization within a wood matrix by in situ XRD

RSC Advances

Brushite mineral shows potential in wood reinforcement and development of hybrid calcium phosphat... more Brushite mineral shows potential in wood reinforcement and development of hybrid calcium phosphate-based wood composites that could be particularly attractive in the construction sector as an environmentally friendly building material.

Research paper thumbnail of Impact of Cellulolytic Fungi on Biodegradation of Hemp Shives and Corn Starch-Based Composites with Different Flame-Retardants

Microorganisms

Biocomposite boards (BcBs) composed of hemp shives and corn starch are known as thermal insulatin... more Biocomposite boards (BcBs) composed of hemp shives and corn starch are known as thermal insulating or structural building materials. Therefore, they must be stable during exploitation. However, BcBs are exposed to microorganisms present in the environment, and it is of great interest to investigate the biodegradation behaviour of these materials. This work identified microorganisms growing on BcBs that contain either Flovan CGN or expandable graphite as flame retardants and selected fungi such as Rhizopus oryzae and Aspergillus fumigatus to test the way they affect the materials of interest. For this purpose, the enzymatic activity of cellulases and amylases produced by these organisms were determined. In addition, the apparent density as well as compressive strength of the affected boards were evaluated. The results showed that apparent density and compressive strength deteriorated in BcB composition with the Flovan CGN flame retardant. At the same time, the level of deterioration ...

Research paper thumbnail of The protective coatings of the bio-based composite boards formed using the drying and semi-drying oils

Proceedings of 1st Corrosion and Materials Degradation Web Conference

Research paper thumbnail of Influence of SiO2 microdust to gas cement concrete with mixed binding material strength characteristics

Autoklavinių akytųjų betonų (AAC) gamybos metu naudojant tam tikras gamybos atliekas galima pager... more Autoklavinių akytųjų betonų (AAC) gamybos metu naudojant tam tikras gamybos atliekas galima pagerinti jo stiprumines savybes. Gamybos atliekos naudojamos pakankamai mažais kiekiais ir jų kaina nėra didelė, todėl galima pagerinti AAC stiprumines savybes pakankamai mažomis išlaidomis. Šiame darbe tirtas SiO2 mikrodulkių (SM) poveikis AAC, su mišria rišamąja medžiaga, stipruminėms savybėms. Tirti keturių sudėčių bandiniai: kontrolinis (be SM priedo), su 0,5 % SM, su 1,0 % SM ir su 1,5 % SM. Darbe aprašyta sudėties skaičiavimo bei bandinių formavimo metodika. Pateikti gniuždymo stiprio rezultatai,gauti atlikus gniuždymo stiprio bandy-mą (buvo gniuždomi 70x70x70 mm bandiniai) presu. Pagal standartą LST 1469, naudojant gautus gniuždymo stiprio rezulta-tus, pagal empirines lygtis, apskaičiuotos lenkimo stiprio bei tempimo stiprio reikšmės. Gauti eksperimentiniai rezultatai apdoroti programa „STATISTICA“ ir gauta gniuždymo stiprio priklausomybė nuo tankio bei SM priedo kiekio.Santrauka angl...

Research paper thumbnail of Mechanical performance of biodegradable hemp shivs and corn starch-based biocomposite boards

Modern Building Materials, Structures and Techniques (MBMST), 2019

For the production of traditional building materials, excavated natural resources are used. The p... more For the production of traditional building materials, excavated natural resources are used. The production process of such materials requires high-energy demands, wherefore, high amounts of CO2 gases, which have a great impact on climate change, are emitted. Only a small part of such materials is effectively recycled and reused. Generally, they are transported to landfills, which rapidly expand and may pollute the soil, groundwater and air. Currently, a great attention is paid to the production of novel building materials. The aim is to use as less excavated materials as possible and replace them by natural renewable resources. Therefore, the recycling and utilisation at the end of life cycle of such materials would be easier and generation of waste would reduce. This way, the efforts of switching to circular economy are being put. One of the approaches – wider application of vegetable-based raw materials (cultivated and uncultivated agricultural plants). The usage of fibre hemp shi...

Research paper thumbnail of Isolation and Identification of Fungi Growing on Fibre Hemp Shive Based Thermal Insulation Materials

Proceedings of the 21th Conference for Junior Researchers „Science – Future of Lithuania“, 2018

Green thermal insulation materials are ecological materials with hemp, linen, jute, wood waste, m... more Green thermal insulation materials are ecological materials with hemp, linen, jute, wood waste, maize starch, and other types of waste added to polymer-based composites. Such kind of materials are susceptible to the microbial action which can lead to changes of physico-chemical properties of materials, their destruction and also health problems in humans. Here, we isolated and identified several fungal strains that grow on fibre hemp shive based materials. Three isolates were identified as belonging to Trichoderma (Hypocrea) genus. Our further experiments will be concentrated on the monitoring of growth of newly isolated fungi on and/or inside the materials of interest, isolation and characterisation of the hydrolytic enzymes as well as following the mode of material destruction caused by the fungal growth.

Research paper thumbnail of Termoizoliacinio Kompozito Iš Kanapiu Spaliu Šilumos Laidumo Tyrimai

Vienas is penkiu pagrindiniu tikslu, kuriu privalo siekti visos Europos Sajungos (ES) salys, yra ... more Vienas is penkiu pagrindiniu tikslu, kuriu privalo siekti visos Europos Sajungos (ES) salys, yra Klimato kaita ir energetikos tvarumas. ES salys, tame tarpe ir Lietuva turi sumažinti siltnamio efekta sukelianciu duju kieki 20 % (arba net 30 %, jei tam bus tinkamos salygos), palyginti su 1990 m. rodikliais; 20 % energijos turtu buti gaminama is atsinaujinanciuju saltiniu; energijos vartojimo efektyvumas turtu buti padidintas 20 %. Didžiausios energijos sanaudos tenka pastatu sildymui, kuris priklauso nuo pastatu atitvaru efektyvumo. Statybos sektoriaus energijos sanaudos apima 50 % viso energijos suvartojimo. Norint mažinti pastatu energijos sanaudas, reikia didinti atitvaru sudtiniu elementu energetini efektyvuma tiek ju gamyboje, tiek eksploatacinmis salygomis. Naudojant augalins kilms medžiagas, tokias, kaip kanapiu spaliai, kurie turi dideli portuma bei akyta struktura, didinamas atitvaru efektyvumas, mažinami gamybos kastai, salyginai mažinama CO2 duju emisija, nes augdami augal...

Research paper thumbnail of The cellulase activity of the fungi that grow on the bio-based thermal insulation composite materials

Proceedings of 1st International Electronic Conference on Microbiology, 2020

Research paper thumbnail of The Effect of Different Plant Oil Impregnation and Hardening Temperatures on Physical-Mechanical Properties of Modified Biocomposite Boards Made of Hemp Shives and Corn Starch

Materials, 2020

In this study, tung tree and linseed drying oils, as well as semi-drying hempseed oil, were analy... more In this study, tung tree and linseed drying oils, as well as semi-drying hempseed oil, were analyzed as the protective coatings for biocomposite boards (BcB) made of hemp shives, corn starch binder, and the performance-enhancing additives. The hydrophobization coatings were formed at 40, 90, and 120 °C temperatures, respectively. The physical-mechanical properties such as the compressive strength, thermal conductivity, dimensional stability, water absorption, and swelling were tested. In addition, scanning electron microscopy (SEM) was employed for the analysis of the board microstructure to visualize the oil fills and impregnation in pores and voids. It was demonstrated that the compressive strength of oil-modified BcBs compared to uncoated BcBs (at 10% of relative deformation) increased by up to 4.5-fold and could reach up to 14 MPa, water absorption decreased up to 4-fold (from 1.34 to 0.37 kg/m2), swelling decreased up to 48% (from 8.20% to 4.26%), whereas the thermal conductivi...

Research paper thumbnail of Evaluation of self-thermally treated wood plastic composites from wood bark and rapeseed oil-based binder

Construction and Building Materials, 2020

h i g h l i g h t s Dust in wood bark particles act as nucleation centres affecting polymer matri... more h i g h l i g h t s Dust in wood bark particles act as nucleation centres affecting polymer matrix. Favourable wood bark particles and rapeseed oil-based binder ratio is 0.85. Mechanical performance improves through sufficient interfacial adhesion. Self-thermally treated biocomposite is a cost-effective product.

Research paper thumbnail of Closed Cell Rigid Polyurethane Foams Based on Low Functionality Polyols: Research of Dimensional Stability and Standardised Performance Properties

Materials, 2020

Currently, polyurethane foam producers come across the several problems when petroleum-based poly... more Currently, polyurethane foam producers come across the several problems when petroleum-based polyols are replaced with low functionality biomass, or waste-based, polyols. In addition, the dilemma is intensified with regulations that require full or partial replacement of blowing agents that can cause high ozone depletion with alternatives like water, which causes the formation of CO2. Therefore, these gases diffuse out of the foam so quickly that the polymeric cell walls cannot withstand the pressure, consequently causing huge dimensional changes at ambient temperature and humidity. Even though the theoretical stoichiometric balance is correct, the reality shows that it is not enough. Therefore, polyethylene terephthalate waste-based polyol was chosen as a low functionality polyol which was modified with high functionality sucrose-based polyol in order to obtain dimensionally stable polyurethane foams in the density range of 30–40 kg/m3. These more stable foams are characterized by ...

Research paper thumbnail of Long-term curing impact on properties, mineral composition and microstructure of hemp shive-cement composite

Construction and Building Materials, 2018

h i g h l i g h t s Mechanical properties of composite during long-term hardening period increase... more h i g h l i g h t s Mechanical properties of composite during long-term hardening period increase. Changes of properties are caused by continuing hydration and carbonation procesess. Hydration and carbonisation depends from Al 2 (SO 4) 3 and Ca(OH) 2 ratio with cement. Qualitative analysis of the composite composition is conducted using X-ray and DTA.

Research paper thumbnail of Assessment of Structure Influence on Thermal Conductivity of Hemp Shives Composite

Environmental Engineering and Management Journal, 2016

In past ten years area of green technologies and materials was the most growing industry sector i... more In past ten years area of green technologies and materials was the most growing industry sector in the world. It is related with global warming, air pollution and energy saving. Building sector intensively increased air pollution and is related with high energy consumptions. The use of renewable or recyclable materials can reduce these problems. In current work, thermal insulating materials from hemp shives and corn starch were investigated. Structures of various shives fractions were analyzed. Different sized shives by two indicators bulk density and thermal conductivity were compared. Composite materials with various shives fractions and corn starch were prepared. Different thermal treatment for composite hardening was used. Thermal conductivity and compressive strength of composites were determined. Thermal insulating composites with a high compressive strength and low thermal conductivity were developed.

Research paper thumbnail of Investigation of the Influence of Paraffin Production Wastes on the Properties of Ceramic Articles

Glass and Ceramics, 2019

The possibility of using paraffin production wastes (PPW; 2.5-10 wt.%) in the production of porou... more The possibility of using paraffin production wastes (PPW; 2.5-10 wt.%) in the production of porous ceramic was investigated. The addition of 2.5% PPW increases the strength of the ceramic in compression. Increasing PPW to 10% significantly increases the apparent porosity of the ceramic.

Research paper thumbnail of Effect of propylene glycol, rapeseed glycerine, and corn starch modified polyol blends parameters on the properties of thermal insulating polyurethane foams

Journal of Cellular Plastics, 2019

Water-blown polyurethane foams have some drawbacks such as intensive shrinkage, relatively high d... more Water-blown polyurethane foams have some drawbacks such as intensive shrinkage, relatively high density, skin peeling phenomena post blowing, and longer demold time. These drawbacks can be partially or fully eliminated by varying the characteristics of the main components. Therefore, aliphatic polyester rapeseed polyol produced via fermentation was mixed with common modifiers, such as propylene glycol, rapeseed glycerine, and corn starch. The impact of molecular weight and hydroxyl values of their mixtures was evaluated by testing the obtained bio-based polyurethane foams for reaction kinetics, some structural parameters, density, compressive strength, structure morphology, the change in thermal conductivity, dimensional stability, and long-term water absorption by total immersion. Keeping in mind the generation of carbon dioxide during foaming, it was interesting to study the change in the thermal conductivity after 1 day and 30 days after foam production. Propylene-glycol-modified foams had competing dimensional stability, reduced density, faster foam curing capability, lowest water absorption, and shortest demold time due to the obtained open cell structure.

Research paper thumbnail of Mechanical Performance of Biodegradable Thermoplastic Polymer-Based Biocomposite Boards from Hemp Shivs and Corn Starch for the Building Industry

Materials, 2019

Bio-sourced materials combined with a polymer matrix offer an interesting alternative to traditio... more Bio-sourced materials combined with a polymer matrix offer an interesting alternative to traditional building materials. To contribute to their wider acceptance and application, an investigation into the use of wood-polymer composite boards is presented. In this study, biocomposite boards (BcB) for the building industry are reported. BcB are fabricated using a dry incorporation method of corn starch (CS) and hemp shiv (HS) treatment with water at 100 °C. The amount of CS and the size of the HS fraction are evaluated by means of compressive bending and tensile strength, as well as microstructure. The results show that the rational amount of CS independently of HS fraction is 10 wt.%. The obtained BcB have compressive stress at 10% of deformation in the range of 2.4–3.0 MPa, bending of 4.4–6.3 MPa, and tensile strength of 0.23–0.45 MPa. Additionally, the microstructural analysis shows that 10 wt.% of CS forms a sufficient amount of contact zones that strengthen the final product.

Research paper thumbnail of Rapeseed-based polyols and paper production waste sludge in polyurethane foam: Physical properties and their prediction models

Industrial Crops and Products, 2018

Intervention into the present building industry is the main strategy of the European Commission i... more Intervention into the present building industry is the main strategy of the European Commission in order to achieve one of its planned aims regarding the reduction of greenhouse gas emissions up to 20% up by 2020 and up to 80% by 2050. Therefore, it is necessary to develop not only energetically efficient but also more environmentally friendly materials. This work presents bio-based propylene glycol and paper waste sludge particles modified polyurethane foams, their physical properties and their prediction models. The conducted research has revealed that paper waste sludge particles negatively affect dimensional changes. In order to eliminate the negative impact of paper waste sludge, bio-based propylene glycol is used. The obtained results have shown that this raw material allows development of dimensionally and structurally stable polyurethane foams used as a thermal insulating layer having the following properties: density in the range of 40-50 kg/m 3 , compressive strength in the range of 193-243 kPa, thermal conductivity in the range of 0.0349-0.0359 W/(m•K), long-term water absorption in the range of 6-11 vol.% and water vapour transmission factor in the range of 26.2-40.9. On the basis of the results, prediction models are suggested for the most important physical properties of propylene glycol and paper production waste sludge particles modified polyurethane foams.

Research paper thumbnail of Statybinių kompozitų su pluoštinių kanapių spaliais tyrimai

Disertacijoje nagrinėjama ekologiškų kompozitų, kuriuose kaip užpildai naudojami pluoštinių kanap... more Disertacijoje nagrinėjama ekologiškų kompozitų, kuriuose kaip užpildai naudojami pluoštinių kanapių (Canabis Sativa L) spaliai (PKS), savybės. Pagrindiniai tyrimo objektai yra pluoštinių kanapių spaliai, rišikliai tokie kaip cementas, molis, kalkės, krakmolas, sapropelis, taip pat kompozito, susidedančio iš PKS ir minėtųjų rišiklių savybės. Pagrindinis disertacijos tikslas sukurti formavimo mišinio sudėtį bei technologiją ekologiškam daugiafunkciniam kompozitui. Disertaciją sudaro įvadas, trys skyriai, bendrosios išvados, naudotos literatūros ir autoriaus publikacijų disertacijos tema sąrašai. Pirmasis skyrius skirtas literatūros apžvalgai. Jame pateikta bendra informacija apie kompozitus, pluoštinių kanapių perdirbimo, panaudojimo galimybių analizė. Šiame skyriuje pateikta bendra informacija apie pluoštinę kanapę, jos panaudojimas pramonėje, konkrečiai statybos sektoriuje, apžvelgtos jos savybės. Apžvelgta literatūra susijusi su tyrimams naudotais rišikliais, detaliau išanalizuota cementinis rišiklis, bei procesai vykstantys jo rišimosi metu. Šiame skyriuje išanalizuotos kompozitų, kuriuose kaip užpildas naudoti pluoštinių kanapių spaliai, savybės. Skyriaus pabaigoje pateiktos literatūrinės apžvalgos išvados ir disertacijos uždaviniai Antrajame skyriuje aprašytos tyrimams naudotos medžiagos, pateiktos pagrindinės jų charakteristikos. Taip pat aprašyti taikyti tyrimų metodai ir naudota įranga. Trečiajame skyriuje pateikta pluoštinių kanapių spalių (PKS) užpildo savybių tyrimų rezultatai bei struktūros analizė. Ištirtas kompozitas su sapropelio rišikliu, nustatyta rišiklio kiekio, užpildo granuliometrijos, technologinių parametrų, tokių kaip formavimo mišinio apspaudimo lygis, priedų (armuojančiojo priedo bei hidrofobizuojančiojo priedo) poveikis kompozito fizikinėms bei mechaninėms savybėms bei ištirta kompozito mikro struktūra. Ištirtos kompozito su cementiniu rišikliu fizikinės mechaninės savybės bei struktūra, parinkti racionalūs mineralizuojančiojo bei plastifikuojančiojo priedų kiekiai, atlikti rentgentografiniai tyrimai. Disertacijos tema paskelbti 5 straipsniai: vienas Thomson Reuters Web of Science duomenų bazėje bei turintis cituojamumo rodiklį, du-straipsnių rinkiniuose, įtrauktuose į Thomson Reuters duomenų bazę, vienas-recenzuojamoje tarptautinės konferencijos medžiagoje bei vienas-respublikinės konferencijos medžiagoje. Disertacijos tema perskaityti 8 pranešimai Lietuvos bei kitų šalių konferencijose.

Research paper thumbnail of Physical Properties of Building Blocks from Hemp Shives Aggregate and Cementitious Binder, Manufactured in the Expanded Clay (Vibro Pressing) Production Line

Materials Science Forum

Scientific literature mostly aims at investigation of composites with fibre hemp shives (FHS) agg... more Scientific literature mostly aims at investigation of composites with fibre hemp shives (FHS) aggregate and lime binder, although, such materials are characterised by pretty low mechanical properties. In order to obtain higher mechanical properties of a composite, it is appropriate to use cementitious binder. This work investigates physical properties of blocks from hemp shives aggregate and cementitious binder, manufactured in the expanded clay production line using vibro pressing technology. Following properties of the blocks are determined: freeze-thaw resistance, compressive strength, thermal conductivity and density. Thermal resistance according to EN ISO 6946 for the block with cavities is calculated as well. It is found that compressive strength of FHS-cement blocks may be up to 3.18 MPa when the density is of ~850 kg/m3 and thermal conductivity up to 0.135 W/(m∙K). It is found as well that the decrease of compressive strength is 8.7% after 25 freeze-thaw cycles.

Research paper thumbnail of Performance Analysis of Loose-Fill Thermal Insulation from Wood Scobs Coated with Liquid Glass, Tung Oil, and Expandable Graphite Mixture

Materials

The current study presents the results of monitoring the behavior of loose-fill thermal insulatin... more The current study presents the results of monitoring the behavior of loose-fill thermal insulating material for buildings made of wood scobs (WS), which were coated with one, two, and three component-based coatings from liquid glass (LG), tung oil (TO), and expandable graphite (EG). The thermal conductivity of samples in the dry state and under normal laboratory conditions, short-term water absorption by partial immersion, surface wettability, and water vapor permeability were evaluated, and regression equations describing the variations in numerical values of specified properties under different amounts of each coating component were presented. It was shown that LG and TO act as hydrophobic layers that, in conjunction, reduce water absorption by a maximum of 274%, have a contact angle equal to 86°, and lower thermal conductivity by 55% in the dry state due to the specifics of the layer formed on the surface of WS. The addition of EG to LG coating resulted in insignificantly changed...

Research paper thumbnail of Brushite mineralised Scots pine (Pinus sylvestris L.) sapwood – revealing mineral crystallization within a wood matrix by in situ XRD

RSC Advances

Brushite mineral shows potential in wood reinforcement and development of hybrid calcium phosphat... more Brushite mineral shows potential in wood reinforcement and development of hybrid calcium phosphate-based wood composites that could be particularly attractive in the construction sector as an environmentally friendly building material.

Research paper thumbnail of Impact of Cellulolytic Fungi on Biodegradation of Hemp Shives and Corn Starch-Based Composites with Different Flame-Retardants

Microorganisms

Biocomposite boards (BcBs) composed of hemp shives and corn starch are known as thermal insulatin... more Biocomposite boards (BcBs) composed of hemp shives and corn starch are known as thermal insulating or structural building materials. Therefore, they must be stable during exploitation. However, BcBs are exposed to microorganisms present in the environment, and it is of great interest to investigate the biodegradation behaviour of these materials. This work identified microorganisms growing on BcBs that contain either Flovan CGN or expandable graphite as flame retardants and selected fungi such as Rhizopus oryzae and Aspergillus fumigatus to test the way they affect the materials of interest. For this purpose, the enzymatic activity of cellulases and amylases produced by these organisms were determined. In addition, the apparent density as well as compressive strength of the affected boards were evaluated. The results showed that apparent density and compressive strength deteriorated in BcB composition with the Flovan CGN flame retardant. At the same time, the level of deterioration ...

Research paper thumbnail of The protective coatings of the bio-based composite boards formed using the drying and semi-drying oils

Proceedings of 1st Corrosion and Materials Degradation Web Conference

Research paper thumbnail of Influence of SiO2 microdust to gas cement concrete with mixed binding material strength characteristics

Autoklavinių akytųjų betonų (AAC) gamybos metu naudojant tam tikras gamybos atliekas galima pager... more Autoklavinių akytųjų betonų (AAC) gamybos metu naudojant tam tikras gamybos atliekas galima pagerinti jo stiprumines savybes. Gamybos atliekos naudojamos pakankamai mažais kiekiais ir jų kaina nėra didelė, todėl galima pagerinti AAC stiprumines savybes pakankamai mažomis išlaidomis. Šiame darbe tirtas SiO2 mikrodulkių (SM) poveikis AAC, su mišria rišamąja medžiaga, stipruminėms savybėms. Tirti keturių sudėčių bandiniai: kontrolinis (be SM priedo), su 0,5 % SM, su 1,0 % SM ir su 1,5 % SM. Darbe aprašyta sudėties skaičiavimo bei bandinių formavimo metodika. Pateikti gniuždymo stiprio rezultatai,gauti atlikus gniuždymo stiprio bandy-mą (buvo gniuždomi 70x70x70 mm bandiniai) presu. Pagal standartą LST 1469, naudojant gautus gniuždymo stiprio rezulta-tus, pagal empirines lygtis, apskaičiuotos lenkimo stiprio bei tempimo stiprio reikšmės. Gauti eksperimentiniai rezultatai apdoroti programa „STATISTICA“ ir gauta gniuždymo stiprio priklausomybė nuo tankio bei SM priedo kiekio.Santrauka angl...

Research paper thumbnail of Mechanical performance of biodegradable hemp shivs and corn starch-based biocomposite boards

Modern Building Materials, Structures and Techniques (MBMST), 2019

For the production of traditional building materials, excavated natural resources are used. The p... more For the production of traditional building materials, excavated natural resources are used. The production process of such materials requires high-energy demands, wherefore, high amounts of CO2 gases, which have a great impact on climate change, are emitted. Only a small part of such materials is effectively recycled and reused. Generally, they are transported to landfills, which rapidly expand and may pollute the soil, groundwater and air. Currently, a great attention is paid to the production of novel building materials. The aim is to use as less excavated materials as possible and replace them by natural renewable resources. Therefore, the recycling and utilisation at the end of life cycle of such materials would be easier and generation of waste would reduce. This way, the efforts of switching to circular economy are being put. One of the approaches – wider application of vegetable-based raw materials (cultivated and uncultivated agricultural plants). The usage of fibre hemp shi...

Research paper thumbnail of Isolation and Identification of Fungi Growing on Fibre Hemp Shive Based Thermal Insulation Materials

Proceedings of the 21th Conference for Junior Researchers „Science – Future of Lithuania“, 2018

Green thermal insulation materials are ecological materials with hemp, linen, jute, wood waste, m... more Green thermal insulation materials are ecological materials with hemp, linen, jute, wood waste, maize starch, and other types of waste added to polymer-based composites. Such kind of materials are susceptible to the microbial action which can lead to changes of physico-chemical properties of materials, their destruction and also health problems in humans. Here, we isolated and identified several fungal strains that grow on fibre hemp shive based materials. Three isolates were identified as belonging to Trichoderma (Hypocrea) genus. Our further experiments will be concentrated on the monitoring of growth of newly isolated fungi on and/or inside the materials of interest, isolation and characterisation of the hydrolytic enzymes as well as following the mode of material destruction caused by the fungal growth.

Research paper thumbnail of Termoizoliacinio Kompozito Iš Kanapiu Spaliu Šilumos Laidumo Tyrimai

Vienas is penkiu pagrindiniu tikslu, kuriu privalo siekti visos Europos Sajungos (ES) salys, yra ... more Vienas is penkiu pagrindiniu tikslu, kuriu privalo siekti visos Europos Sajungos (ES) salys, yra Klimato kaita ir energetikos tvarumas. ES salys, tame tarpe ir Lietuva turi sumažinti siltnamio efekta sukelianciu duju kieki 20 % (arba net 30 %, jei tam bus tinkamos salygos), palyginti su 1990 m. rodikliais; 20 % energijos turtu buti gaminama is atsinaujinanciuju saltiniu; energijos vartojimo efektyvumas turtu buti padidintas 20 %. Didžiausios energijos sanaudos tenka pastatu sildymui, kuris priklauso nuo pastatu atitvaru efektyvumo. Statybos sektoriaus energijos sanaudos apima 50 % viso energijos suvartojimo. Norint mažinti pastatu energijos sanaudas, reikia didinti atitvaru sudtiniu elementu energetini efektyvuma tiek ju gamyboje, tiek eksploatacinmis salygomis. Naudojant augalins kilms medžiagas, tokias, kaip kanapiu spaliai, kurie turi dideli portuma bei akyta struktura, didinamas atitvaru efektyvumas, mažinami gamybos kastai, salyginai mažinama CO2 duju emisija, nes augdami augal...

Research paper thumbnail of The cellulase activity of the fungi that grow on the bio-based thermal insulation composite materials

Proceedings of 1st International Electronic Conference on Microbiology, 2020

Research paper thumbnail of The Effect of Different Plant Oil Impregnation and Hardening Temperatures on Physical-Mechanical Properties of Modified Biocomposite Boards Made of Hemp Shives and Corn Starch

Materials, 2020

In this study, tung tree and linseed drying oils, as well as semi-drying hempseed oil, were analy... more In this study, tung tree and linseed drying oils, as well as semi-drying hempseed oil, were analyzed as the protective coatings for biocomposite boards (BcB) made of hemp shives, corn starch binder, and the performance-enhancing additives. The hydrophobization coatings were formed at 40, 90, and 120 °C temperatures, respectively. The physical-mechanical properties such as the compressive strength, thermal conductivity, dimensional stability, water absorption, and swelling were tested. In addition, scanning electron microscopy (SEM) was employed for the analysis of the board microstructure to visualize the oil fills and impregnation in pores and voids. It was demonstrated that the compressive strength of oil-modified BcBs compared to uncoated BcBs (at 10% of relative deformation) increased by up to 4.5-fold and could reach up to 14 MPa, water absorption decreased up to 4-fold (from 1.34 to 0.37 kg/m2), swelling decreased up to 48% (from 8.20% to 4.26%), whereas the thermal conductivi...

Research paper thumbnail of Evaluation of self-thermally treated wood plastic composites from wood bark and rapeseed oil-based binder

Construction and Building Materials, 2020

h i g h l i g h t s Dust in wood bark particles act as nucleation centres affecting polymer matri... more h i g h l i g h t s Dust in wood bark particles act as nucleation centres affecting polymer matrix. Favourable wood bark particles and rapeseed oil-based binder ratio is 0.85. Mechanical performance improves through sufficient interfacial adhesion. Self-thermally treated biocomposite is a cost-effective product.

Research paper thumbnail of Closed Cell Rigid Polyurethane Foams Based on Low Functionality Polyols: Research of Dimensional Stability and Standardised Performance Properties

Materials, 2020

Currently, polyurethane foam producers come across the several problems when petroleum-based poly... more Currently, polyurethane foam producers come across the several problems when petroleum-based polyols are replaced with low functionality biomass, or waste-based, polyols. In addition, the dilemma is intensified with regulations that require full or partial replacement of blowing agents that can cause high ozone depletion with alternatives like water, which causes the formation of CO2. Therefore, these gases diffuse out of the foam so quickly that the polymeric cell walls cannot withstand the pressure, consequently causing huge dimensional changes at ambient temperature and humidity. Even though the theoretical stoichiometric balance is correct, the reality shows that it is not enough. Therefore, polyethylene terephthalate waste-based polyol was chosen as a low functionality polyol which was modified with high functionality sucrose-based polyol in order to obtain dimensionally stable polyurethane foams in the density range of 30–40 kg/m3. These more stable foams are characterized by ...

Research paper thumbnail of Long-term curing impact on properties, mineral composition and microstructure of hemp shive-cement composite

Construction and Building Materials, 2018

h i g h l i g h t s Mechanical properties of composite during long-term hardening period increase... more h i g h l i g h t s Mechanical properties of composite during long-term hardening period increase. Changes of properties are caused by continuing hydration and carbonation procesess. Hydration and carbonisation depends from Al 2 (SO 4) 3 and Ca(OH) 2 ratio with cement. Qualitative analysis of the composite composition is conducted using X-ray and DTA.

Research paper thumbnail of Assessment of Structure Influence on Thermal Conductivity of Hemp Shives Composite

Environmental Engineering and Management Journal, 2016

In past ten years area of green technologies and materials was the most growing industry sector i... more In past ten years area of green technologies and materials was the most growing industry sector in the world. It is related with global warming, air pollution and energy saving. Building sector intensively increased air pollution and is related with high energy consumptions. The use of renewable or recyclable materials can reduce these problems. In current work, thermal insulating materials from hemp shives and corn starch were investigated. Structures of various shives fractions were analyzed. Different sized shives by two indicators bulk density and thermal conductivity were compared. Composite materials with various shives fractions and corn starch were prepared. Different thermal treatment for composite hardening was used. Thermal conductivity and compressive strength of composites were determined. Thermal insulating composites with a high compressive strength and low thermal conductivity were developed.

Research paper thumbnail of Investigation of the Influence of Paraffin Production Wastes on the Properties of Ceramic Articles

Glass and Ceramics, 2019

The possibility of using paraffin production wastes (PPW; 2.5-10 wt.%) in the production of porou... more The possibility of using paraffin production wastes (PPW; 2.5-10 wt.%) in the production of porous ceramic was investigated. The addition of 2.5% PPW increases the strength of the ceramic in compression. Increasing PPW to 10% significantly increases the apparent porosity of the ceramic.

Research paper thumbnail of Effect of propylene glycol, rapeseed glycerine, and corn starch modified polyol blends parameters on the properties of thermal insulating polyurethane foams

Journal of Cellular Plastics, 2019

Water-blown polyurethane foams have some drawbacks such as intensive shrinkage, relatively high d... more Water-blown polyurethane foams have some drawbacks such as intensive shrinkage, relatively high density, skin peeling phenomena post blowing, and longer demold time. These drawbacks can be partially or fully eliminated by varying the characteristics of the main components. Therefore, aliphatic polyester rapeseed polyol produced via fermentation was mixed with common modifiers, such as propylene glycol, rapeseed glycerine, and corn starch. The impact of molecular weight and hydroxyl values of their mixtures was evaluated by testing the obtained bio-based polyurethane foams for reaction kinetics, some structural parameters, density, compressive strength, structure morphology, the change in thermal conductivity, dimensional stability, and long-term water absorption by total immersion. Keeping in mind the generation of carbon dioxide during foaming, it was interesting to study the change in the thermal conductivity after 1 day and 30 days after foam production. Propylene-glycol-modified foams had competing dimensional stability, reduced density, faster foam curing capability, lowest water absorption, and shortest demold time due to the obtained open cell structure.

Research paper thumbnail of Mechanical Performance of Biodegradable Thermoplastic Polymer-Based Biocomposite Boards from Hemp Shivs and Corn Starch for the Building Industry

Materials, 2019

Bio-sourced materials combined with a polymer matrix offer an interesting alternative to traditio... more Bio-sourced materials combined with a polymer matrix offer an interesting alternative to traditional building materials. To contribute to their wider acceptance and application, an investigation into the use of wood-polymer composite boards is presented. In this study, biocomposite boards (BcB) for the building industry are reported. BcB are fabricated using a dry incorporation method of corn starch (CS) and hemp shiv (HS) treatment with water at 100 °C. The amount of CS and the size of the HS fraction are evaluated by means of compressive bending and tensile strength, as well as microstructure. The results show that the rational amount of CS independently of HS fraction is 10 wt.%. The obtained BcB have compressive stress at 10% of deformation in the range of 2.4–3.0 MPa, bending of 4.4–6.3 MPa, and tensile strength of 0.23–0.45 MPa. Additionally, the microstructural analysis shows that 10 wt.% of CS forms a sufficient amount of contact zones that strengthen the final product.

Research paper thumbnail of Rapeseed-based polyols and paper production waste sludge in polyurethane foam: Physical properties and their prediction models

Industrial Crops and Products, 2018

Intervention into the present building industry is the main strategy of the European Commission i... more Intervention into the present building industry is the main strategy of the European Commission in order to achieve one of its planned aims regarding the reduction of greenhouse gas emissions up to 20% up by 2020 and up to 80% by 2050. Therefore, it is necessary to develop not only energetically efficient but also more environmentally friendly materials. This work presents bio-based propylene glycol and paper waste sludge particles modified polyurethane foams, their physical properties and their prediction models. The conducted research has revealed that paper waste sludge particles negatively affect dimensional changes. In order to eliminate the negative impact of paper waste sludge, bio-based propylene glycol is used. The obtained results have shown that this raw material allows development of dimensionally and structurally stable polyurethane foams used as a thermal insulating layer having the following properties: density in the range of 40-50 kg/m 3 , compressive strength in the range of 193-243 kPa, thermal conductivity in the range of 0.0349-0.0359 W/(m•K), long-term water absorption in the range of 6-11 vol.% and water vapour transmission factor in the range of 26.2-40.9. On the basis of the results, prediction models are suggested for the most important physical properties of propylene glycol and paper production waste sludge particles modified polyurethane foams.

Research paper thumbnail of Statybinių kompozitų su pluoštinių kanapių spaliais tyrimai

Disertacijoje nagrinėjama ekologiškų kompozitų, kuriuose kaip užpildai naudojami pluoštinių kanap... more Disertacijoje nagrinėjama ekologiškų kompozitų, kuriuose kaip užpildai naudojami pluoštinių kanapių (Canabis Sativa L) spaliai (PKS), savybės. Pagrindiniai tyrimo objektai yra pluoštinių kanapių spaliai, rišikliai tokie kaip cementas, molis, kalkės, krakmolas, sapropelis, taip pat kompozito, susidedančio iš PKS ir minėtųjų rišiklių savybės. Pagrindinis disertacijos tikslas sukurti formavimo mišinio sudėtį bei technologiją ekologiškam daugiafunkciniam kompozitui. Disertaciją sudaro įvadas, trys skyriai, bendrosios išvados, naudotos literatūros ir autoriaus publikacijų disertacijos tema sąrašai. Pirmasis skyrius skirtas literatūros apžvalgai. Jame pateikta bendra informacija apie kompozitus, pluoštinių kanapių perdirbimo, panaudojimo galimybių analizė. Šiame skyriuje pateikta bendra informacija apie pluoštinę kanapę, jos panaudojimas pramonėje, konkrečiai statybos sektoriuje, apžvelgtos jos savybės. Apžvelgta literatūra susijusi su tyrimams naudotais rišikliais, detaliau išanalizuota cementinis rišiklis, bei procesai vykstantys jo rišimosi metu. Šiame skyriuje išanalizuotos kompozitų, kuriuose kaip užpildas naudoti pluoštinių kanapių spaliai, savybės. Skyriaus pabaigoje pateiktos literatūrinės apžvalgos išvados ir disertacijos uždaviniai Antrajame skyriuje aprašytos tyrimams naudotos medžiagos, pateiktos pagrindinės jų charakteristikos. Taip pat aprašyti taikyti tyrimų metodai ir naudota įranga. Trečiajame skyriuje pateikta pluoštinių kanapių spalių (PKS) užpildo savybių tyrimų rezultatai bei struktūros analizė. Ištirtas kompozitas su sapropelio rišikliu, nustatyta rišiklio kiekio, užpildo granuliometrijos, technologinių parametrų, tokių kaip formavimo mišinio apspaudimo lygis, priedų (armuojančiojo priedo bei hidrofobizuojančiojo priedo) poveikis kompozito fizikinėms bei mechaninėms savybėms bei ištirta kompozito mikro struktūra. Ištirtos kompozito su cementiniu rišikliu fizikinės mechaninės savybės bei struktūra, parinkti racionalūs mineralizuojančiojo bei plastifikuojančiojo priedų kiekiai, atlikti rentgentografiniai tyrimai. Disertacijos tema paskelbti 5 straipsniai: vienas Thomson Reuters Web of Science duomenų bazėje bei turintis cituojamumo rodiklį, du-straipsnių rinkiniuose, įtrauktuose į Thomson Reuters duomenų bazę, vienas-recenzuojamoje tarptautinės konferencijos medžiagoje bei vienas-respublikinės konferencijos medžiagoje. Disertacijos tema perskaityti 8 pranešimai Lietuvos bei kitų šalių konferencijose.