| 1. |
- Balksten, Kristin, et al.
(author)
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Internal Retrofitting with Hemp-Lime on Brick Masonry : a Study to Prevent Damage Caused by Sodium Sulphate
- 2021
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In: Proceedings of SWBSS 2021 : Fifth International Conference on Salt Weathering of Buildings and Stone Sculptures - Fifth International Conference on Salt Weathering of Buildings and Stone Sculptures. - 9789463664394 ; , s. 277-286
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Conference paper (peer-reviewed)abstract
- In Sweden there are a great number of neo-gothic churches built in brick masonryaround 1870-1910. They are constructed as massive masonry walls with façadebricks attached to a core of massive red bricks. In the majority of these churchesthere is a presence of sodium sulphate causing salt damages. The source of the salts is known to be the red masonry bricks and the damage occurs both internally and externally on the walls. Damages occurred already after a couple of years after the churches were built and ever since they caused expensive renovations with little or no durability. As the sodium sulphate crystallizes inside the plaster the damages cause spalling of the surface.Since 2016 a method to prevent or delay salt damages has been studied and evaluated. By adding a layer of insulation on the internal wall the microclimate on and nearby the plaster surface can be changed and the damages caused by crystallization decrease. When adding an insulating layer made by hemp-lime plaster before adding the lime plaster the salts cause less visible damage to the internal plaster.Full-scale test surfaces have been made both in the laboratory and inside twochurches. After two and three years respectively, there are no visible salts causingdamages inside the churches, where salts previously came back directly after eachrenovation. In the wall in the laboratory at Lund University the bricks where contaminated with sodium sulphate and internally rendered with hemp-lime plaster with a lime plaster surface finish. Even though there are lots of salt-related damages externally there are thus far, more than two years after construction, no signs of any damage internally.
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| 2. |
- Balksten, Kristin, 1977-, et al.
(author)
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Understanding Deterioration due to Salt and Ice Crystallization in Scandinavian Massive Brick Masonry
- 2021
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In: Heritage. - : MDPI. - 2571-9408. ; 4:1, s. 349-370
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Journal article (peer-reviewed)abstract
- Extensive durability problems such as weathering and degradation are found in historic Scandinavian brick masonry buildings, especially from the neo-Gothic period. These are largely due to the crystallization of salts and frost action in the bricks and mortars. This article aims to show and illustrate which salts and crystals are found in historic brick masonry buildings and to describe their appearance and behavior. An additional aim is to explore possibilities of preventing salt-related damage on internal masonry wall surfaces, such as using hemp-lime sacrificial plaster beneath the plaster. The objective is to show the mechanisms behind salt-related problems and to perform a case study and a laboratory study on salt-damaged brick masonry containing sodium sulphate. In order to prevent and stop damage to the masonry, it is important to be able to identify the nature of the salt damage and the type of salt that caused the damage. Neo-Gothic brick masonry buildings require well-planned, continuous maintenance of the masonry. It is therefore of the utmost importance to have an understanding of the complex functions of the masonry and of the salts that can cause damage to these historic buildings.
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| 3. |
- Farsäter, Karin, et al.
(author)
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Building status obtained before renovating multifamily buildings in Sweden
- 2019
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In: Journal of Building Engineering. - : Elsevier BV. - 2352-7102.
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Journal article (peer-reviewed)abstract
- The aim of this study was to analyse how energy use, building physics properties and indoor environment data have been obtained in the initial evaluation phases of multifamily building renovations in Sweden. Between 1964 and 1975, approximately one million homes were built in Sweden. These buildings are now in need of renovation. To perform proper status assessment of a building before a renovation is important both to make decisions on renovation measures on correct information as well as to be able to perform follow-ups of renovation projects. The analyses in this study was performed with questionnaires in eight case studies. Studied data included energy use, building physics properties and indoor environmental factors. The study shows that information about a building's status, and the subsequent renovation process, is often linked to one or just a few people involved in the project without any systematic documentation. When they leave their employment, due to changing jobs or retirement, documentation about the condition of the building, material choices and decision processes is often lost.
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| 4. |
- Farsäter, Karin, et al.
(author)
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Erfarenhetsåterföring vid renovering
- 2017
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In: Bygg och teknik. - 0281-658X. ; :2, s. 38-39
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Journal article (pop. science, debate, etc.)abstract
- Nationellt Renoveringscentrum (NRC) bildades 2013 för att arbeta med kunskapshöjning och informationsspridning om en effektiv renoveringsprocess. Centret siktar på att samla och föra vidare kunskap om hur renovering av befintlig bebyggelse kan genomföras både effektivt för involverade aktörer såväl som socialt, ekonomiskt och miljömässigt hållbart för samhället. Kunskap från både akademi och näringsliv samlas och sprids på en bred front. Renoveringsbehovet i Sverige idag sträcker sig över hela landet och över hela det byggda beståndet (offentliga lokaler, kontorsbyggnader, villor samt inte minst flerbostadshus.)
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| 5. |
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Hampakalk : Tilläggsisolering på reveterade trähus och saltskadat tegelmurverk - Slutrapport
- 2019
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Editorial collection (other academic/artistic)abstract
- Historiska byggnaders energiprestanda behöver hållbart förbättras samtidigt som kulturhistoriska värden bevaras. Ett byggnadsmaterial som hampakalk skulle kunna uppfylla en ny funktion i renovering av historiska byggnader. Syftet var att finna en effektiv och resurssnål metod för tilläggsisolering av reveterade och putsade historiska trä- och tegelhus som är kompatibel med stommen, ökar energieffektiviteten, skapar en hälsosam och god inomhusmiljö samt bidrar till att bevarade kulturhistoriska värden. Målet med projektet var att utreda lämplighet och användbarhet av hampakalk som tilläggsisoleringsmaterial i ett kallt svenskt klimat med svåra fuktförhållanden. Det var väsentligt att klargöra förutsättningarna för eventuell mikrobiell påverkan på materialet. Ett delmål med projektet var därför att utvärdera risken för mikrobiell påväxt på hampakalk och att ta fram nyckeltal för dess kritiska fuktnivåer. Huruvida hampakalk skulle kunna fungera som tilläggsisolering på saltvittrande tegelmurverk har också undersökts. Här har det dels handlat om att förstå salternas beteende och skadeverkan samt vad som kan bidra till ett minimerande av skador. Där har hampakalk som invändigt tilläggsisoleringsmaterial provats och utvärderats för att se om det kan bidra med ändrat mikroklimat och ändrad salttransport och därigenom minskade saltskador på putsytan. Det finns ett stort bestånd av hållbara byggnader, företrädesvis från perioden 1700-tal till 1930-tal, som uppförts dels med trästomme som putsats, dels av tegel. Framförallt blev båda dessa byggtekniker allt vanligare under 1800-talet då städerna började byggas med ett utökat krav på brandskydd och termisk komfort. Idag är dessa byggnader ofta i behov av underhåll eller renovering och i samband med detta behöver de kunna anpassas efter moderna krav på termisk komfort och energieffektivisering. Samtidigt besitter de höga kulturhistoriska värden och skall därmed förändras/underhållas/renoveras med stor varsamhet, med traditionella material och metoder och med kompatibla lösningar. Resultatet av projektet har visat att hampakalk fungerar utmärkt för att tilläggsisolera historiska trä eller tegelbyggnader. Uppmätt minskning av energianvändning för uppvärmning var 33-53 % i fallstudierna jämfört med originalkonstruktionen. Tilläggsisolering av hampakalk gav en bra fuktbalans i såväl murverket som trästommen, förutsatt att det kombineras med en för konstruktionen anpassad kalkputs. Som invändig putsbärare på saltskadat tegelmurverk gav hampakalken ett stabilare mikroklimat med minskat antal saltkristallisationscykler och därmed ett fördröjt skadeförlopp. Hampakalk kan bidra till god ljudmiljö och ett bibehållet brandskydd. Hampakalk kan användas där kulturhistoriska värden skall bevaras. Det gäller framförallt byggnader som står inför renovering eller omrenovering, där ett material behövs som är kompatibelt med såväl trä- och tegelstommar som traditionell kalkputs vilka skall fortsätta utgöra kulturhistoriska värdebärande element för byggnaden.
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| 6. |
- Johansson, Pär, 1986, et al.
(author)
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Performance of insulation materials for historic buildings: case-studies comparing super insulation materials and hemp-lime
- 2018
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In: Proceedings of the 3rd International Conference on Energy Efficiency in Historic Buildings, EEHB2018. ; , s. 80-88
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Conference paper (peer-reviewed)abstract
- There is a challenge to reduce the energy use of historic buildings while preserving their cultural values. New materials and solutions are being developed that could contribute to improving the energy performance of historic buildings without altering their character defining elements. The aim of this paper is to technically evaluate and compare a ‘high-tech’ material (VIP) with a ‘low-tech’ material (hemp-lime) for adding insulation to historical façades. This comparison was made with respect to thermal properties and moisture performance, as well as available environmental impact data. The VIPs are characterised by reaching a high level of insulation although they are thin, which means they do not alter the proportions of the building the way thick layers of insulation do. Hemp-lime on the other hand has the advantage of being in line with the traditional materials already present in historic buildings.
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| 7. |
- Johansson, Sanne, et al.
(author)
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Risk for Mould Growth on Hemp-Lime at Different Relative Humidity
- 2021
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In: Bio-Based Building Materials : Selected peer-reviewed full text papers from the 4th International Conference on Bio-Based Building Materials (ICBBM 2021), June 16-18, 2021, Barcelona, Spain - Selected peer-reviewed full text papers from the 4th International Conference on Bio-Based Building Materials (ICBBM 2021), June 16-18, 2021, Barcelona, Spain. - 2674-1237 .- 2674-1229. - 9783035726992 - 9783035736991 ; 3, s. 588-594
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Book chapter (peer-reviewed)abstract
- Microbial growth often thrives in humid conditions, at high relative humidity. Moulds are complex organisms; many types of mould are able to survive strong variations in humidity and temperature, such as those on building façades. For some building materials a critical relative humidity is determined, which functions as a theoretical threshold; at this (or lower) relative humidity microbial growth will likely not occur. Hemp-lime is a building material that consists of hemp shiv (the woody core parts of the hemp stem) and building lime. It is a material that can be used for walls, and even though it has been used for more than 20 years, thusfar little is known about its critical moisture levels for microbial growth. The aim of this research was therefore to determine at what relative humidity microbial growth occurs on carbonated hemp-lime material, and to study if there is a protective influence of a carbonated lime binder on the hemp shiv. The objective was to study microbial growth on hemp shiv, hemp-lime and on hemp with a thin layer of lime at three relative humidity (75 %, 85 % and 95 %) and at two different temperatures (15°C and 23°C); conditions that could occur naturally in a hemp-lime façade exposed to high rain loads in a northern European climate. Hemp shiv seems to have a relatively low resistance to microbial growth, similar to that of wood. However, because the hemp is protected by lime it can withstand much higher relative humidity without microbial growth occurring on the material. The critical moisture level for hemp-lime seemed to occur between 75 and 85 % RH, while the material was completely without microbial growth at 75 % RH. The lime had a protective effect on the hemp and acted as a mould inhibitor, both over time and with varying temperature and humidity.
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| 8. |
- Kanters, Jouri, et al.
(author)
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The potential of agricultural residual waste as building material in South Sweden
- 2023. - 16
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In: CISBAT 2023 Conference. ; 2600
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Conference paper (peer-reviewed)abstract
- A literature review and statistical analysis of the potential of agricultural residual waste as building materials in South Sweden was carried out. This data showed that there is a clear capacity for the use of mainly straw-generating crops as building materials in the region.
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| 9. |
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| 10. |
- Ranefjärd, Oskar, et al.
(author)
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Hygrothermal Properties and Performance of Bio-Based Insulation Materials Locally Sourced in Sweden
- 2024
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In: Materials. - 1996-1944. ; 17:9
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Journal article (peer-reviewed)abstract
- In recent years, there has been a paradigm shift in the building sector towards more sustainable, resource efficient, and renewable materials. Bio-based insulation derived from renewable resources, such as plant or animal fibres, is one promising group of such materials. Compared to mineral wool and polystyrene-based insulation materials, these bio-based insulation materials generally have a slightly higher thermal conductivity, and they are significantly more hygroscopic, two factors that need to be considered when using these bio-based insulation materials. This study assesses the hygrothermal properties of three bio-based insulation materials: eelgrass, grass, and wood fibre. All three have the potential to be locally sourced in Sweden. Mineral wool (stone wool) was used as a reference material. Hygrothermal material properties were measured with dynamic vapour sorption (DVS), transient plane source (TPS), and sorption calorimetry. Moisture buffering of the insulation materials was assessed, and their thermal insulation capacity was tested on a building component level in a hot box that exposed the materials to a steady-state climate, simulating in-use conditions in, e.g., an external wall. The tested bio-based insulation materials have significantly different sorption properties to stone wool and have higher thermal conductivity than what the manufacturers declared. The hot-box experiments showed that the insulating capacity of the bio-based insulators cannot be reliably calculated from the measured thermal conductivity alone. The results of this study could be used as input data for numerical simulations and analyses of the thermal and hygroscopic behaviour of these bio-based insulation materials.
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