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  • 101.
    Helsing, Elisabeth
    RISE, SP – Sveriges Tekniska Forskningsinstitut, CBI Betonginstitutet AB, Betong & Berg.
    Lagar och regler vid renovering: en översikt2016Report (Other academic)
    Abstract [sv]

    Ordet renovering existerar inte i något av våra regelverk. Begreppet renovering ingår i det som benämns ändring av en byggnad i vilket ombyggnad ingår som en del.De tekniska egenskapskrav som gäller vid nybyggnad gäller i princip också vid ändring. Vid ombyggnad ska de uppfyllas för hela byggnaden eller, om detta inte är rimligt, den del av byggnaden som påtagligt förnyas genom ombyggnaden. Vid ändring gäller de för ändringen. Enkelt avhjälpta hinder mot tillgänglighet till eller användbarhet av lokaler dit allmänheten har tillträde ska dock alltid avhjälpas.När det gäller ändringar tillkommer dock ett krav på varsamhet, d.v.s. att man tar hänsyn till byggnadens karaktärsdrag och tar till vara byggnadens tekniska, historiska, kulturhistoriska, miljömässiga och konstnärliga värden. En byggnad som är särskilt värdefull från historisk, kulturhistorisk, miljömässig eller konstnärlig synpunkt får inte förvanskas.Kravet på varsamhet och förbudet mot förvanskning innebär att det är nödvändigt att ibland göra avsteg från de rent tekniska egenskapskraven som gäller vid nybyggnad när man genomför en ändring.Ändringsreglerna i BBR och EKS avser att förtydliga vilka av de egenskapskrav som gäller vid nybyggnad som man inte får göra avsteg från och i vilka fall det är möjligt att mot bakgrund av ändringens omfattning och byggnadens förutsättningar göra anpassningar.Vad som avses med ändringens omfattning och byggnadens förutsättningar förtydligas i BBR. När det gäller ändringens omfattning utgås från hur stor del av byggnaden som berörs, konsekvenserna för de tekniska egenskapskraven och byggnadens kulturvär-den. Motiveringar med hänsyn till byggnadens förutsättningar kan dels ha att göra med om det är fråga om omfattande ändringar eller ny användning. I sådana fall finns få skäl till avsteg från nybyggnadsnivån. Är det fråga om en kulturhistoriskt värdefull byggnad finns det större skäl. Tekniska skäl, som t.ex. att utrymme saknas eller att uppfylla ett krav medför att ett annat inte blir uppfyllt på ett godtagbart sätt kan också åberopas. Ekonomiska skäl baserade på byggnadens placering, utformning eller tekniska förutsättningar kan också vara motiveringar. Låg likviditet får dock inte beaktas. Därutöver kan även boendekvaliteter av praktisk eller upplevelsemässig art utgöra skäl för anpassning.Kravnivån vid ändring varierar också beroende på vilket krav det är fråga om. I BBR och EKS används följande terminologi:Ska: I princip inget utrymme för avvikelseSka ...om inte synnerliga skäl: Visst modifieringsutrymme finns om byggnaden ändå kan antas få godtagbara egenskaper och det inte är möjligt att tillgodose kravet fullt ut utan höga kostnader eller påtagligt negativa konsekvenser för övriga tekniska egen-skapskrav eller byggnadens kulturvärden.Ska eftersträvas: Kraven ska tillgodoses om det kan ske till en skälig kostnad och inte medför negativa konsekvenser för övriga tekniska egenskapskrav, byggnadens kulturvärden eller andra boende- och brukarkvaliteter. Har byggnaden redan den eftersträvade egenskapen finns inte utrymme för att försämra den om det inte finns synnerliga skäl.Dock får anpassningar av kraven aldrig medföra en oacceptabel risk för människors hälsa och säkerhetEn hel del av det som står i BBR, EKS och Hissreglerna är allmänna råd och inte absoluta krav, och ger exempel på godtagna konstruktionslösningar. Dessa är inte alltid möjliga att tillämpa vid ändring, utan man måste söka andra lösningar som ändå ger samma säkerhet.Reglerna ger för de olika egenskapskraven vägledning för eventuella anpassningar, förslag på alternativa lösningar t.ex. moderniseringar då äldre byggteknik använts.I hyreslagstiftningen är det främst två aspekter som berör ändringar: Hyresgästinfly-tande vid förbättrings- och ändringsarbete och villkor vid större förändring av hyran. I båda dessa fall krävs godkännande av hyresgäster eller tillstånd av hyresnämnd. Dock står det inget om att hyresgäster kan var med och påverka vad som ska ändras, t.ex. hur omfattande ändringarna ska vara.När det gäller bostadsrätter är det hur stora beslut ska tas som avhandlas. Om alla medlemmar inte är eniga har hyresnämnden en roll även här. En bostadsrättsinneha-vare har rätt att frånträda en bostadsrätt om avgiftsändringarna blir för stora. Bostadssätten återgår då till föreningen, mot skälig ersättning.

  • 102.
    Helsing, Elisabeth
    RISE, SP – Sveriges Tekniska Forskningsinstitut, CBI Betonginstitutet AB.
    Nyheter och nyttigheter om CE-märkning och standadisering inom betongområdet2014In: CBI-nytt, ISSN 0349-2060, no 1, p. 4-5Article in journal (Other academic)
  • 103.
    Herlin, Alexander
    RISE, SP – Sveriges Tekniska Forskningsinstitut, CBI Betonginstitutet AB.
    Ballastens inverkan på betongens termiska egenskaper2014In: Svensk Bergs & Brukstidning, ISSN 0039-6435, Vol. 93, no 2Article in journal (Other academic)
  • 104.
    Herlin, Alexander
    RISE, SP – Sveriges Tekniska Forskningsinstitut, CBI Betonginstitutet AB.
    Mätning av energi- och effektbehov i minihus2013In: CBI-nytt, ISSN 0349-2060, no 1, p. 4-Article in journal (Other academic)
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  • 105. Holmgren, Jonas
    et al.
    Lagerblad, Björn
    RISE, SP – Sveriges Tekniska Forskningsinstitut, CBI Betonginstitutet AB.
    Krympning av sprutbetong2008In: Bygg och Teknik, ISSN 0281-658X, E-ISSN 2002-8350, Vol. 100, no 7, p. 30-34Article in journal (Other academic)
  • 106. Hughes, JJ
    et al.
    Lindqvist, Jan Erik
    RISE, SP – Sveriges Tekniska Forskningsinstitut, CBI Betonginstitutet AB.
    RILEM TC 203-RHM: Repair mortars for historic masonry: The role of mortar in masonry: an introduction to requirements for the design of repair mortars2012In: Materials and Structures, ISSN 1359-5997, E-ISSN 1871-6873, Vol. 45, no 9, p. 1287–1294-Article in journal (Refereed)
    Abstract [en]

    Mortar has been in use for many thousands of years and is integral to most masonry construction. Its use is widespread in every culture where masonry is constructed. It is present in the majority of the global built cultural heritage, and is therefore a major consideration in building conservation. The effective design of a mortar for repairing masonry depends on a clear understanding of its function. The main functional uses of mortar in masonry are classified as bedding, pointing, grout, render, plaster, flooring and mortars for surface repairs. The requirements that each type of mortar must meet in service depend on its environmental exposure and its role in the masonry element that it is found within (e.g. issues such as historic authenticity, aesthetics, resistance to moisture ingress, structural integrity, and service life). Technical requirements such as adhesion, strength, elasticity, water and vapour transmittance, drying behaviour, thermal dilatation, ability to deal with salt contamination and freeze-thaw cycling, and its aesthetic properties can be quantified. Mortar properties can be adjusted by varying ingredients and their proportions, to meet the differing technical requirements.

  • 107.
    Jacobsson, Lars
    et al.
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Bygg och Mekanik, Strukturer och Komponenter.
    Appelquist, Karin
    RISE, SP – Sveriges Tekniska Forskningsinstitut, CBI Betonginstitutet AB.
    Lindkvist, Jan Erik
    RISE, SP – Sveriges Tekniska Forskningsinstitut, CBI Betonginstitutet AB.
    Spalling Experiments on Large Hard Rock Specimens2015In: Rock Mechanics and Rock Engineering, ISSN 0723-2632, E-ISSN 1434-453X, Vol. 48, no 4, p. 1485-1503Article in journal (Refereed)
    Abstract [en]

    Specimens of coarse-grained Äspö diorite were axially compressed to observe stress-induced spalling. The specimens had a novel design characterized by two manufactured large radius notches on opposite sides. The tangential stress occurring in the notches aimed to represent the tangential loading around a circular opening. Fracture stages were monitored by acoustic emission measurements. Rock chips were formed similar to those found in situ, which indicates a similar fracture process. Slabs were cut out from the specimens and impregnated using a fluorescent material to visualize the cracks. The cracks were subsequently examined by the naked eye and by means of microscopy images, from which fracture paths could be identified and related to different minerals and their crystallographic orientations. The microscopy analyses showed how the stress field and the microstructure interact. Parallel cracks were formed 2–4 mm below the surface, sub-parallel to the direction of the maximum principal stress. The crack initiation, the roles of minerals such as feldspar, biotite and quartz and their grain boundaries and crystallographic directions are thoroughly studied and discussed in this paper. Scale effects, which relate to the stress gradient and microstructure, are discussed.

  • 108.
    Jacobsson, Lars
    et al.
    RISE, SP – Sveriges Tekniska Forskningsinstitut.
    Flansbjer, Mathias
    RISE, SP – Sveriges Tekniska Forskningsinstitut.
    Andersson, Lars
    RISE, SP – Sveriges Tekniska Forskningsinstitut.
    Appelquist, Karin
    RISE, SP – Sveriges Tekniska Forskningsinstitut, CBI Betonginstitutet AB.
    Normal Loading and Shear Tests on Rock2016Report (Other academic)
  • 109.
    Jacobsson, Lars
    et al.
    RISE, SP – Sveriges Tekniska Forskningsinstitut.
    Flansbjer, Mathias
    RISE, SP – Sveriges Tekniska Forskningsinstitut.
    Andersson, Lars
    RISE, SP – Sveriges Tekniska Forskningsinstitut.
    Appelquist, Karin
    RISE, SP – Sveriges Tekniska Forskningsinstitut, CBI Betonginstitutet AB.
    Normal Loading and Shear Tests on Rock Joints from Olkiluoto2016Report (Other academic)
  • 110.
    Jacobsson, Lars
    et al.
    RISE, SP – Sveriges Tekniska Forskningsinstitut.
    Flansbjer, Mathias
    RISE, SP – Sveriges Tekniska Forskningsinstitut.
    Johannesson, Pär
    RISE, SP – Sveriges Tekniska Forskningsinstitut.
    Lindqvist, Jan-Erik
    RISE, SP – Sveriges Tekniska Forskningsinstitut.
    Brander, Linus
    RISE, SP – Sveriges Tekniska Forskningsinstitut, CBI Betonginstitutet AB.
    Schouenborg, Björn
    RISE, SP – Sveriges Tekniska Forskningsinstitut.
    ONKALO POSE Experiment - Geological and Rock Mechanical Tests on Samples from a Heating Test at Olkiluoto2016Report (Other academic)
  • 111.
    Jacobsson, Lars
    et al.
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Sveriges tekniska forskningsinstitut, SP – Sveriges Tekniska Forskningsinstitut / Hållfasthet (BMh).
    Flansbjer, Mathias
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Sveriges tekniska forskningsinstitut, SP – Sveriges Tekniska Forskningsinstitut / Hållfasthet (BMh).
    Schouenborg, Björn
    RISE, SP – Sveriges Tekniska Forskningsinstitut, CBI Betonginstitutet AB.
    Grelk, Bent
    Smits, Arwen
    Expert System for Dimensioning of Facade Cladding2010In: Proceedings of Global Stone Congress 2010, 2010, , p. 1-4Conference paper (Refereed)
    Abstract [en]

    Proceedings of the Global Stone Congress 2010, Alicante Spain, 2-5 March 2010 2010 (Extern vetenskaplig bok)

  • 112.
    Jacobsson, Lars
    et al.
    RISE, SP – Sveriges Tekniska Forskningsinstitut.
    Sandström, Johan
    RISE, SP – Sveriges Tekniska Forskningsinstitut.
    Flansbjer, Mathias
    RISE, SP – Sveriges Tekniska Forskningsinstitut.
    Sjögren, Torsten
    RISE, SP – Sveriges Tekniska Forskningsinstitut.
    Brander, Linus
    RISE, SP – Sveriges Tekniska Forskningsinstitut, CBI Betonginstitutet AB.
    ONKALO POSE Experiment - Laboratory Determination of Density, Porosity and Mechanical Anisotropy of Gneiss and Granite2016Report (Other academic)
  • 113.
    Jacobsson, Mikael
    RISE, SP – Sveriges Tekniska Forskningsinstitut, CBI Betonginstitutet AB.
    Betongskador i vattenverk2016Report (Other academic)
    Abstract [sv]

    Rapporten ger en översikt över betongskador i svenska vattenverk. Den presenterarbilder på typiska betongskador, hur de kan uppstå och var man kanhitta dem i vattenreningsprocessen. Den ska inspirera vattenverkens personalatt lägga märke till betongskador i tid. Detta för att undvika mycketgenomgripande reparationer av allvarligare skador i framtiden.Betong är det i särklass vanligaste materialet i svenska vattenverk. Det ärmycket hållfast, men det finns det flera kemiska och fysikaliska processersom påverkar materialet negativt. Nedbrytningen av betongen kan ses påbassängernas sidor, både våta och torra. Men det är inte helt ovanligt att skadoruppstår även inuti en betongkonstruktion utan att det syns på utsidan.Oavsett var skadorna börjar kan tillsynes obetydliga betongskador göra attkonstruktionens bärighet försämras avsevärt.De flesta vattenverk lider av likartade betongskador. Yterosion och urlakningav betongytan är de vanligaste formerna av synliga betongskador påden våta sidan. På den torra sidan är det vanligare med armeringskorrosion,sprickbildning och läckage. De skador som är vanligast inuti en betongkonstruktionär expansion, korrosion och svartrost. Svartrost bildas när armeringsjärnkorroderar under syrefattiga förhållanden. Den expanderar intepå samma sätt som annan rost utan kan fylla ut håligheter i betongen utanatt det syns på ytan. De inre skadorna är särskilt allvarliga eftersom det kanvara svårt att observera dem utan att det görs en utförlig tillståndsbedömning.Inre skador kan på sikt göra att hela konstruktionens bärighet gårförlorad. Därför är det viktigt att regelbundet låta undersöka betongkonstruktionerna.Projektet genomfördes av CBI Betonginstitutet, som utför åtskilliga tillståndsbedömningarpå betongkonstruktioner i Sverige varje år. I många fallvisar det sig att konstruktionerna är i relativt dåligt skick. Troligen beror detpå att de flesta skador utvecklas mycket långsamt och gradvis. Dessutomär vattenverkspersonalen inte alltid medveten om hur betongskador kan seut eller hur allvarliga de kan vara. Om medvetenheten hos personalen höjdesskulle troligen många betongskador upptäckas tidigare och reparationerskulle kunna sättas in innan skadorna har blivit allvarliga och kostsammaatt åtgärda.Även om en skada upptäcks behöver den inte alltid repareras direkt.I stället bör man om man hittar en skada låta en betongexpert utföra entillståndsbedömning på konstruktionen. Det innebär att man undersökeromfattningen av konstruktionens skador, om de behöver repareras omedelbarteller senare, vilken form av reparation som bör utföras och med vilkamaterial. Man kan också få rekommendationer om hur den reparerade konstruktionenkan skyddas i fortsättningen. Om en reparation inte behöverutföras direkt bör i stället konstruktionen övervakas med vissa tidsintervall.

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  • 114.
    Johansson-Selander, Anders
    et al.
    RISE, SP – Sveriges Tekniska Forskningsinstitut, CBI Betonginstitutet AB.
    Janz, Mårten
    Penetration profiles of water repellent agents in concrete as a function of time: determined with FTIR-spectrometer2010In: Nordic Concrete Research, ISSN 0800-6377, Vol. 41, no 1, p. 51-60Article in journal (Other academic)
  • 115.
    Kalinowski, Mariusz
    RISE, SP – Sveriges Tekniska Forskningsinstitut, CBI Betonginstitutet AB.
    Hur reaktiv är ballast från mellansverige?2014In: CBI-nytt, ISSN 0349-2060, no 2, p. 9-Article in journal (Other academic)
  • 116.
    Kalinowski, Mariusz
    RISE, SP – Sveriges Tekniska Forskningsinstitut, CBI Betonginstitutet AB.
    Sulfatbeständighet med kalkstensfiller2013In: CBI-nytt, ISSN 0349-2060, no 1, p. 2-3Article in journal (Other academic)
    Download full text (pdf)
    FULLTEXT01
  • 117.
    Karami, Peyman
    et al.
    KTH Royal Institute of Technology, Sweden.
    Al-Ayish, Nadia
    RISE, SP – Sveriges Tekniska Forskningsinstitut, CBI Betonginstitutet AB, Hållbara byggnadsverk. KTH Royal Institute of Technology, Sweden.
    Gudmundsson, Kjartan
    KTH Royal Institute of Technology, Sweden.
    A comparative study of the environmental impact of Swedish residential buildings with vacuum insulation panels2015In: Energy and Buildings, ISSN 0378-7788, E-ISSN 1872-6178, Vol. 109, p. 183-194Article in journal (Refereed)
    Abstract [en]

    A large part of the energy consumption in the European Union member states is related to space heating, a significant share of which is due to transmission losses through the building envelope. Vacuum insulation panels (VIPs), with unique thermal insulation properties, do therefore provide an interesting alternative for the building industry. This paper presents the results of a life cycle analysis (LCA) study that compares the environmental impact of three hypothetical buildings, a standard residential building, a regular well-insulated building and a building insulated with VIPs. The environmental impact includes the global warming potential (GWP) and the primary energy (PE) use, from the material production stage to the building operational phase (50 years). The cradle-to-gate environmental impact categories of ozone depletion potential (ODP), acidification potential (AP) and eutrophication potential (EP) of all building components are also assessed. The study shows a comparatively lower operational energy for the VIP insulated building and a relatively lower total greenhouse gas emission as well as the possibility to save significant living space. The results also show that the VIPs have measurable environmental impact during the product stage while the core material of the VIPs has considerable impact on the results.

  • 118. Kargol, M A
    et al.
    Mueller, Urs
    RISE, SP – Sveriges Tekniska Forskningsinstitut, CBI Betonginstitutet AB.
    Properties and performance of silane: blended cement systems2013In: Materials and Structures, ISSN 1359-5997, E-ISSN 1871-6873, Vol. 46, no 9, p. 1429-1439Article in journal (Refereed)
    Abstract [en]

    The paper presents the results of a study dealing with the performance of water repellents on hardened blended cement pastes. Since on the European market Portland cement does not play the dominant role anymore and due to the new national and European policies concerning Greenhouse Gases and sustainability, cement manufacturers produce more and more blended cements (CEM II-CEM V). Nevertheless, the majority of experience concerning the efficacy of water repellents is gained from Portland cement; therefore knowledge in regard to the interactions of blended cement with water repellent agent is minimal. Two silane-based products were applied on 'fresh' and carbonated cement substrates containing limestone, fly ash, slag and trass, and were investigated in terms of their functionality. The evaluation of the treatments' performance and effectiveness were assessed using various laboratory measurements. Hydrophobicity, water absorption, colour changes and the penetration depth of silanes into the substrate were evaluated before and after artificial aging experiments. Moreover, the outdoor weathering test was performed to shed light on treated surface appearance in a 'real' outdoor environment. The results showed that surface wettability was independent on water ingress or colour variations, especially for cement specimens artificially aged by accelerated carbonation. Cement pastes containing slag and trass seemed to more distinctly affect the water repellents' surface performance.

  • 119.
    Kraft, Lars
    RISE, SP – Sveriges Tekniska Forskningsinstitut, CBI Betonginstitutet AB.
    En lösning till att undvika delaminering i betonggolv2014In: Bygg och Teknik, ISSN 0281-658X, E-ISSN 2002-8350, Vol. 106, no 8, p. 42-Article in journal (Other academic)
  • 120.
    Kraft, Lars
    RISE, SP – Sveriges Tekniska Forskningsinstitut, CBI Betonginstitutet AB.
    Hazards of titanium dioxide nanoparticles usage in concrete: pulmonary toxicity literature review2013Report (Refereed)
    Abstract [en]

    Nano-crystalline titanium dioxide is mixed into concrete in order to reduce nitrogen-oxides in urban areas, due to its photocatalytic activation of ultraviolet light. Therefore, it is important to make sure that such additions of titania nanoparticles will not cause any negative side-effects, if any, such as an increase in epidemiological harm. Accordingly, the objective of this report is to answer whether generated nanoparticles (NPs) from concrete containing titania, i.e. photocatalytic concrete, is more toxic than corresponding NPs from conventional concrete, and beside this, deduce whether titania NPs in general are more toxic compared to corresponding fine particles (FP) of titania. A state-of-the-art review is conducted, basically based on papers dealing with how micro- and nanoparticles of TiO2 affect biological systems and on papers with explicit information of nano-sized TiO2 when exposed to living tissue, in vivo or in vitro*. The primary route for body exposure to airborne particles is by inhalation, although ingestion and dermal penetration are also possible routes for NPs to enter the body. Therefore primarily papers concerning lung cell interaction with TiO2 NPs are reviewed. From the literature it is highlighted that the particle size, agglomeration state, crystallinity, surface reactivity, dose, exposure route, experiment duration, species or cells used all play a role in titanium dioxide toxicity. Initially, contradicting facts were found regarding the influence of particle size and surface area on the toxicity of TiO2 NPs. However, on closer inspection it was found that such contradicting results most probably may be explained by differences in particle sizes, crystal shape, dosages, methods etc., in the experimental setups. For example, in many papers NPs seem to induce higher inflammatory response at equivalent mass dose exposure of fine and ultrafine particles but at the same surface area no differences are found between NP and FP toxicity. Likewise, regarding crystal form, in most papers the anatase crystal form seems to be more potent in causing inflammation in cells and animals (guinea-pigs) than the rutile crystal form, whereas a combination of these two phases occasionally seems to be even more potent than the anatase phase alone. Therefore, of great importance for correct interpretation of the results is the physicochemical characterization of the particles such as coatings applied at the surface, the z-potential and the agglomeration grade. In many of the papers reviewed such characterizations are insufficient. This is particularly more common in papers published before 2005. But the scientific branch of nanoparticle toxicology is a fast developing area and the good news is that the knowledge of how to assess the toxicity accurately has increased during the last 4-5 years. Therefore more concise knowledge regarding different NPs’ inherent toxicity to living tissues and the environment will be available increasingly in a continual manner over the next coming years. Specifically, from the papers reviewed, TiO2 NPs do not seem to be much more toxic than their larger counterparts, based on equal surface area. Furthermore, some papers conclude that many studies demonstrate a low hazard potential in mammals or aquatic species even at acute exposure to the ultrafine TiO2 particles. For example, in many rat studies the inflammatory response is transient with time. Compared with other metal oxides, TiO2 is most often less toxic than other elements, such as ZnO, CuO and SiO2 in the different toxicological screening tests. Also, the doses used in the toxicological in vivo studies are 10-1000 times higher compared to any dosages that humans might be exposed to. In summary, we have the following general conclusions:_x000D_ • Nanosized particles are often more potent in inducing toxicological response compared to fine particles of the same composition when delivered at equal mass._x000D_ • At equal surface area but different particle size, similar compounds exhibit similar toxicological characteristics._x000D_ • Nanosized particles (< 50 nm) have the ability to penetrate lung cell membranes whereas larger particles cannot but will instead accumulate outside the cell wall, which also may promote damage to lung tissue. _x000D_ • Generally, titanium dioxide is less toxic than silica. Nanosized silica (microsilica) is frequently used in concrete in large quantities._x000D_ • Addition of titanium dioxide nanoparticles will increase the amount of nanosized particles in the fresh concrete, but will be bound in the cement matrix in hardened concrete._x000D_ • Antropogenically generated particles from photocatalytic concrete pavements will contain less silica-based NPs but more TiO2 NPs. _x000D_ • The amount of nanoparticles generated in concrete pavements will likely be in same order of magnitude regardless of a recipe with or without TiO2 NPs._x000D_ • Naturally or anthropogenically occurring nanoparticles agglomerate as aerosols or agglomerates in medium_x000D_ From all of this it is concluded that it is not likely that using additives of photocatalytic titania in pavements made of concrete will increase the inherent toxicity of the nanoparticles generated from pavement wear from vehicle tires._x000D_ _x000D_

  • 121.
    Kraft, Lars
    RISE, SP – Sveriges Tekniska Forskningsinstitut, CBI Betonginstitutet AB.
    Hårdbetonggjutningar på gammal betong2011In: CBI-nytt, ISSN 0349-2060, no 1, p. 4-6Article in journal (Other academic)
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    FULLTEXT01
  • 122.
    Kraft, Lars
    RISE, SP – Sveriges Tekniska Forskningsinstitut, CBI Betonginstitutet AB.
    Hårdbetonggjutningar på gammal betong2010In: Bygg och Teknik, ISSN 0281-658X, E-ISSN 2002-8350, Vol. 102, no 8, p. 54-64Article in journal (Other academic)
  • 123.
    Kraft, Lars
    RISE, SP – Sveriges Tekniska Forskningsinstitut, CBI Betonginstitutet AB.
    Pågjutningars vidhäftning mot hårdnad betong2012In: Bygg och Teknik, ISSN 0281-658X, E-ISSN 2002-8350, no 8, p. 28-34Article in journal (Other academic)
  • 124.
    Kraft, Lars
    RISE, SP – Sveriges Tekniska Forskningsinstitut, CBI Betonginstitutet AB.
    Studie av vägbetongs fysikaliska egenskaper, med eller utan tillsats av TiOmix2011In: CBI-nytt, ISSN 0349-2060, no 2, p. 4-5Article in journal (Other academic)
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  • 125.
    Kraft, Lars
    RISE, SP – Sveriges Tekniska Forskningsinstitut, CBI Betonginstitutet AB.
    Study on TiOmix replacement in white topping and in shotcrete.: Effects on physical properties2010Report (Refereed)
  • 126.
    Kraft, Lars
    RISE, SP – Sveriges Tekniska Forskningsinstitut, CBI Betonginstitutet AB.
    TIOfield- undersökning om partikelemissioner i trafikmiljö: [Slutrapport]2012Report (Refereed)
    Abstract [sv]

    Denna rapport redovisar resultaten från studier i ett projekt med syfte att undersöka om betongs_x000D_ egenskaper förändras vid en ersättningstillsats av fotokatalytisk titandioxid. Som fotokatalytiskt_x000D_ tillsatsmaterial användes Cementas produkt TiOmix N. Totalt genomfördes fyra delprojekt, vilket_x000D_ resulterat i fyra rapporter. Två typer av betong undersöktes för inblandning av TiOmix N, vägbetong_x000D_ och sprutbetong. Två olika doseringar av TiOmix provades i båda typerna av betong. Betongreceptet_x000D_ i vägbetongen var samma recept som användes vid beläggningen av E4 utanför Uppsala._x000D_ Tryckhållfasthet, böjdraghållfasthet, E-modul, volymstabilitet (krympning), termisk_x000D_ expansionskoefficient, abrasionsmotstånd och frostbeständighet samt fotokatalytisk effekt_x000D_ (reduktionsförmåga av NOx) hos betongen undersöktes. Provningen visade att en dos på 25 kg/m3_x000D_ TiOmix som ersättningstillsats fungerade väl i både vägbetong och sprutbetong. För vägbetongen_x000D_ gjordes därefter även en modellstudie i en provvägsmaskin för jämförelse av slitage och_x000D_ partikelgenerering från dubbdäck på asfalt (ABS16) och vägbetong, med och utan tillsats av TiOmix_x000D_ N. Samtliga beläggningar hade samma stenmaterial (granit). Provning i provvägsmaskinen visade_x000D_ att betongen med TiOmix i det här fallet hade ett högt slitage, högre slitaget än asfalten. Lägst_x000D_ slitage hade dock vägbetongen utan TiOmix. Betongbeläggningarna alstrade fler PM10 partiklar än_x000D_ asfalten, men färre partiklar av nanometerstorlek. En intressant iakttagelse var att TiO2 endast_x000D_ fanns i partikelstorlekar större än 0,1 μm. Till viss del var dock provningen på provvägsmaskinen av_x000D_ betongen med TiOmix misslyckad eftersom den uppvisade så högt slitage. Tryckhållfasthetsprovning_x000D_ och strukturanalys i ljusmikroskop av de förtillverkade provningsplattorna visade att de två_x000D_ betongerna hade olika tryckhållfasthet och att mer TiOmixbetongen hade högre halt tillsatt luft och_x000D_ ett högre vattencementtal. Provningen bör därför upprepas för att få säkra och rättvisa resultat. En_x000D_ litteraturstudie om toxicitet av TiO2 partiklar sammanställdes också. Det mest intressanta_x000D_ slutsatsen från den är att den visar att TiO2 partiklar i de flesta undersökningarna uppvisar en_x000D_ lägre toxicitet än motsvarande partiklar av ZnO, CuO och kvarts. I tidigare toxicitetsstudier på fina_x000D_ partiklar har ofta TiO2 använts som inert referens (dvs, som icke reaktiv referens). Sammantaget_x000D_ visar projektet att man kan tillsätta TiOmix i betong med ersättningsinblandning utan att förändra_x000D_ betongens övriga egenskaper. Analys av genererade partiklar i provvägsmaskinen visar att TiO2_x000D_ partiklar endast förekommer i partiklar större än 0,1 μm. Publicerade forskningsartiklar visar att_x000D_ fina partiklar (0,1 – 10 μm) oftast är mindre toxiska än nanopartiklar (1 – 100 nm) samt att_x000D_ nanopartiklar av TiO2 oftast är mindre toxiskt än motsvarande partiklar av ZnO, CuO och SiO2.

  • 127.
    Kraft, Lars
    et al.
    RISE, SP – Sveriges Tekniska Forskningsinstitut, CBI Betonginstitutet AB.
    Rogers, Patrick
    RISE, SP – Sveriges Tekniska Forskningsinstitut, CBI Betonginstitutet AB.
    Eriksson Brandels, Alexander
    RISE, SP – Sveriges Tekniska Forskningsinstitut, CBI Betonginstitutet AB.
    Gram, Annika
    RISE, SP – Sveriges Tekniska Forskningsinstitut, CBI Betonginstitutet AB.
    Trädgårdh, Jan
    RISE, SP – Sveriges Tekniska Forskningsinstitut, CBI Betonginstitutet AB.
    Wallqvist, Viveca
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Kemi Material och Ytor.
    Experimentalrubber chip concrete mixes for shock absorbent bike lane pavements.2015Conference paper (Refereed)
    Abstract [en]

    In Sweden the amount of cyclists being injured in traffic has increased in recent years. Over 23,000 peopleper annum visit an acute care hospital after being injured whilst cycling. Most bicycle accidents are single“vehicle” accidents (82 %) and the most common collision is with another cyclist. Due to increased healthcare costs and the fact that more city dwelling people choose to cycle instead of going by car - due both tomonetary, environmental and personal health reasons - one is devoted to find solutions to make cyclingsafer. Besides efforts to increase helmet usage among cyclists and safer bike lane design separate from cartraffic, another way to reduce injuries may be achieved by modifying the bike lanes’ properties. This wouldresult in safer cycling and not only reducing non-cranial injuries, but also limit the severity of head injuries forcyclists not wearing a helmet. Thus, the pavement and bicycle lane material must be an efficient absorbentof impact energy. The work here presents efforts on modifying a concrete pavement by replacing coarseaggregates and sand with rubber chips and rubber crumbs to increase the shock absorbent capacity.Altogether, eighteen different mixtures with varying proportions of rubber, cement and sand were preparedand evaluated regarding elastic modulus and compressive strength. A fly-ash cement, microsilica and latexsolution were used in the concrete mixes. From the results obtained the mix with the best impact absorbingproperties, with a low E-modulus and sufficient compressive strength, was chosen for further evaluation.

  • 128.
    Kraft, Lars
    et al.
    RISE, SP – Sveriges Tekniska Forskningsinstitut, CBI Betonginstitutet AB.
    Söderberg, C-F
    Belgisk studie kastar ljus över svenska sprickor2014In: Betong, ISSN 1101-9190, no 6, p. 45-Article in journal (Other academic)
  • 129.
    Kurkinen, Eva-Lotta
    et al.
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Hållbar Samhällsbyggnad, Byggnadsfysik och innemiljö.
    Noren, Joakim
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Hållbar Samhällsbyggnad, Träbyggande och boende.
    Peñaloza, Diego
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Hållbar Samhällsbyggnad, Träbyggande och boende.
    Al-Ayish, Nadia
    RISE, SP – Sveriges Tekniska Forskningsinstitut, CBI Betonginstitutet AB.
    During, Otto
    RISE, SP – Sveriges Tekniska Forskningsinstitut, CBI Betonginstitutet AB.
    Energi och klimateffektiva byggsystem: Miljövärdering av olika stomalternativ2015Report (Other academic)
    Abstract [en]

    In the collaborative forum Positive footprint housing® Riksbyggen is building the Viva residential quarter, which is a sustainability project at the very forefront of what is possible with contemporary construction. The idea is that this residential quarter should be fully sustainable in ecological, economic and social terms. Since 2013, a number of pilot studies have been completed under the auspices of the Viva project framework thanks to financing from the Swedish Energy Agency.

    The various building frame alternatives that have been evaluated are precast concrete, cast in-situ concrete and solid wood, all proposed by leading commercial suppliers. The report includes a specific requirement for equivalent functions during the use phase of the building, B. An interpretation has been provided that investigates the building engineering aspects in detail, as well as an account of the results based on the social community requirements specified in Viva, durability, fire, noise and energy consumption in the Swedish National Board of Building, Planning and Housing building regulations (BBR), plus Riksbyggen’s own requirements, Sweden Green Building Council’s Environmental Building Gold (Miljöbyggnad Guld) and 100-year life cycle. Given that the alternatives have different long-term characteristics (and also that our knowledge of these characteristics itself varies), these functional requirements have been addressed by setting up different scenarios in accordance with the EPD standard EN 15978.

    Because Riksbyggen has specified a requirement for a 100-year life cycle, we have also opted for an analysis period of 100 years.

    The results show no significant differences between concrete and timber structures for the same functions during the life cycle, either for climate or for primary energy. The minor differences reported are accordingly less than the degree of uncertainty involved in the study.

    The available documentation on the composition of the relevant intumescent paint coating on solid wood frames differs from source to source, so it was not possible to fully allow for the significance of this.

    The LCA has not included functional changes in the building linked to load-bearing characteristics, noise, moisture, health or other problems that may result in increased maintenance and replacement. The concrete houses have been dimensioned for 100 years, for instance, in accordance with tried and tested standards and experience. The solid wood house is not dimensioned in the same way, and this has led to us having to assume various scenarios.

    The results also show the following:

     

    • The uncertainties involved in comparing different structures and alternative solutions are very significant. The results are affected by factors such as life cycle, the functional requirements taken into consideration, transportation, design and structural details, etc.

     

    • Variations in the built items and a considerable degree of uncertainty in the assumptions make it difficult to obtain significant results on comparisons. Only actual construction projects with known specific data, declared from a life cycle perspective that takes into account actual building developer

    requirements and involving different scenarios (best, documented and worst-case) for the user stage can currently be compared.

     

    • In the other hand, comparisons restricted to different concrete structures only, or to different timber structures only, ought to involve a lower degree of uncertainty, These would then provide results that are significant as well as improvement requirements that are relevant.

     

    • There is potential for improving concrete by imposing requirements on the material

     

    • There is potential for improving solid wood frames by developing and guaranteeing well-documented long-term characteristics for all functional requirements.

     

    The LCAs were performed as an iterative process where all parties were given the opportunity to submit their viewpoints and suggestions for changes during the course of the work. This helped ensure that all alternatives have been properly thought through.

    Because, during the project, Riksbyggen opted to procure a concrete frame, in the final stage the researchers involved focused on ensuring the procurement process would result in the concrete frame as built meeting the requirements set out above. As things currently stand, the material requirements for the concrete are limited by the production options open to the suppliers, and this is therefore being investigated in the manufacture of precast concrete frames for the Viva cooperative housing association.

     

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  • 130.
    Kurkinen, Eva-Lotta
    et al.
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Hållbar Samhällsbyggnad, Byggnadsfysik och innemiljö.
    Norén, Joakim
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Hållbar Samhällsbyggnad, Träbyggande och boende.
    Peñaloza, Diego
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Hållbar Samhällsbyggnad, Träbyggande och boende.
    Al-Ayish, Nadia
    RISE, SP – Sveriges Tekniska Forskningsinstitut, CBI Betonginstitutet AB.
    During, Otto
    RISE, SP – Sveriges Tekniska Forskningsinstitut, CBI Betonginstitutet AB.
    Energy and climate-efficient construction systems: Environmental assessment of various frame options for buildings in Brf. Viva2018Report (Other academic)
    Abstract [en]

    In the collaborative forum Positive footprint housing® Riksbyggen is building the Viva residential quarter, which is a sustainability project at the very forefront of what is possible with contemporary construction. The idea is that this residential quarter should be fully sustainable in ecological, economic and social terms. Since 2013, a number of pilot studies have been completed under the auspices of the Viva project framework thanks to financing from the Swedish Energy Agency. The various building frame alternatives that have been evaluated are precast concrete, cast in-situ concrete and solid wood, all proposed by leading commercial suppliers. The report includes a specific requirement for equivalent functions during the use phase of the building, B. An interpretation has been provided that investigates the building engineering aspects in detail, as well as an account of the results based on the social community requirements specified in Viva, durability, fire, noise and energy consumption in the Swedish National Board of Building, Planning and Housing building regulations (BBR), plus Riksbyggen’s own requirements, Sweden Green Building Council’s Environmental Building Gold (Miljöbyggnad Guld) and 100-year life cycle. Given that the alternatives have different long-term characteristics (and also that our knowledge of these characteristics itself varies), these functional requirements have been addressed by setting up different scenarios in accordance with the EPD standard EN 15978. Because Riksbyggen has specified a requirement for a 100-year life cycle, we have also opted for an analysis period of 100 years. The results show no significant differences between concrete and timber structures for the same functions during the life cycle, either for climate or for primary energy. The minor differences reported are accordingly less than the degree of uncertainty involved in the study. The available documentation on the composition of the relevant intumescent paint coating on solid wood frames differs from source to source, so it was not possible to fully allow for the significance of this. The LCA has not included functional changes in the building linked to load-bearing characteristics, noise, moisture, health or other problems that may result in increased maintenance and replacement. The concrete houses have been dimensioned for 100 years, for instance, in accordance with tried and tested standards and experience. The solid wood house is not dimensioned in the same way, and this has led to us having to assume various scenarios.

    The results also show the following:

    • The uncertainties involved in comparing different structures and alternative solutions are very significant. The results are affected by factors such as life cycle, the functional requirements taken into consideration, transportation, design and structural details, etc.

    • Variations in the built items and a considerable degree of uncertainty in the assumptions make it difficult to obtain significant results on comparisons. Only actual construction projects with known specific data, declared from a life cycle perspective that takes into account actual building developer requirements and involving different scenarios (best, documented and worst-case) for the user stage can currently be compared.

    • In the other hand, comparisons restricted to different concrete structures only, or to different timber structures only, ought to involve a lower degree of uncertainty. These would then provide results that are significant as well as improvement requirements that are relevant.

    • There is potential for improving concrete by imposing requirements on the material

    • There is potential for improving solid wood frames by developing and guaranteeing well-documented long-term characteristics for all functional requirements.

    The LCAs were performed as an iterative process where all parties were given the opportunity to submit their viewpoints and suggestions for changes during the course of the work. This helped ensure that all alternatives have been properly thought through.

    Because, during the project, Riksbyggen opted to procure a concrete frame, in the final stage the researchers involved focused on ensuring the procurement process would result in the concrete frame as built meeting the requirements set out above. As things currently stand, the material requirements for the concrete are limited by the production options open to the suppliers, and this is therefore being investigated in the manufacture of precast concrete frames for the Viva cooperative housing association.

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    fulltext
  • 131.
    Lagerblad, Björn
    RISE, SP – Sveriges Tekniska Forskningsinstitut, CBI Betonginstitutet AB.
    Betong med krossad ballast2011In: CBI-nytt, ISSN 0349-2060, no 2, p. 2-3Article in journal (Other academic)
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  • 132.
    Lagerblad, Björn
    RISE, SP – Sveriges Tekniska Forskningsinstitut, CBI Betonginstitutet AB.
    Betong tar upp koldioxid under hela sin livstid2009In: Husbyggaren, ISSN 0018-7968, Vol. 51, no 6, p. 36-37Article in journal (Other academic)
    Abstract [sv]

    När cement tillverkas bildas koldioxid. Å andra sidan tar betong upp koldioxid under hela sin livstid. Det viktiga är att minska utsläppen vid tillverkningen av cement och att minska cementhalten i betong.

  • 133.
    Lagerblad, Björn
    RISE, SP – Sveriges Tekniska Forskningsinstitut, CBI Betonginstitutet AB.
    Carbon dioxide capture-rate and mode of carbonation2012In: fib Symposium 2012: Concrete Structures for Sustainable Community - Proceedings, 2012, p. 63-66Conference paper (Refereed)
    Abstract [en]

    In a time perspective, the rate and degree of carbonation is important as regards carbon dioxide capture. It is related to concrete quality, type of binder, local environment and microclimate. The data on outdoor concrete is good. This investigation has sampled and analyzed concrete from indoor environments and crushed concrete as road base etc. The data shows that there are many different kinds of environments and within those there are different types of hindrances that slow down carbonation. To understand this, one must look at the mechanism of carbonation and the effect of the local microclimate. This is the case with dry indoor concrete that has remaining uncarbonated cement grains and cores of portlandite in seemingly carbonated concrete.

  • 134.
    Lagerblad, Björn
    RISE, SP – Sveriges Tekniska Forskningsinstitut, CBI Betonginstitutet AB.
    Krossat berg som ballast till betong2008In: Svensk Bergs och Brukstidning, ISSN 0039-6435, no 4, p. 40-44Article in journal (Other academic)
  • 135.
    Lagerblad, Björn
    RISE, SP – Sveriges Tekniska Forskningsinstitut, CBI Betonginstitutet AB, Hållbara byggnadsverk.
    Mechanism and mode of carbonation of cementitious materials2017Report (Other academic)
    Abstract [en]

    Concrete is the most common and widely used construction material in the world, with a consumption of approximately 1.5 tons per capita annually worldwide. This consumes 3000 million ton of cement, around 400 kg per capita. Sweden consumes around 250 kg of cement per capita.  The production of Portland cement consumes around 3500 MJ energy per ton. In addition, Portland cement production releases considerable amounts of CO2 when limestone is heated and calcinated. With 800 kg of CO2 per ton of cement around 5 % of the global release of CO2 comes from cement clinker production. About half of this comes from the limestone. Concrete, however, also binds CO2 when it is carbonated. In a geological time perspective, all concrete will carbonate and thus half of the released CO2 will be bound to carbonated concrete, which would reduce the environmental impact (Xi et al 2016). I reality the absorption is much less, and is related to the time interval of interest.  How fast CO2 will be absorbed depends on the type of concrete or cementitious material, site of the concrete, amount of CO2 in the environment and the environment as such, etc. It is also depending on the amount CO2 in the atmosphere and the temperature. In the end, to be able to calculate the uptake it is important to find out what happens with the concrete after demolition and if it is possible to increase the speed of carbonation.  This report mainly cover the mechanism and mode of carbonation to be able to get a better and more accurate understanding of how to calculate carbonation and CO2 uptake.  This project was funded by the Swedish Consortium for financing Basic research in the Concrete Field. The consortium members are: Cementa, Färdig Betong, Abetong, Swerock, Betongindustri and Strängbetong.

  • 136.
    Lagerblad, Björn
    RISE, SP – Sveriges Tekniska Forskningsinstitut, CBI Betonginstitutet AB.
    Miljöbetong2009In: CBI nytt, ISSN 0349-2060, no 1, p. 2-3Article in journal (Other academic)
  • 137.
    Lagerblad, Björn
    RISE, SP – Sveriges Tekniska Forskningsinstitut, CBI Betonginstitutet AB.
    Vilka krav kan ställas på ”grön betong”?2012In: Husbyggaren, ISSN 0018-7968, Vol. 54, no 2, p. 34-36Article in journal (Other academic)
  • 138.
    Lagerblad, Björn
    RISE, SP – Sveriges Tekniska Forskningsinstitut, CBI Betonginstitutet AB.
    Återtagning av koldioxid: karbonatisering2008In: Betong, ISSN 1101-9190, no 2, p. 59-61Article in journal (Other academic)
  • 139.
    Lagerblad, Björn
    et al.
    RISE, SP – Sveriges Tekniska Forskningsinstitut, CBI Betonginstitutet AB.
    Bryne, Lars Elof
    Cement hydration and development of texture and bond at interfacial zone between hard rock and shotcrete2014In: Nordic Concrete Research, ISSN 0800-6377, Vol. 50, no 2, p. 263-266Article in journal (Refereed)
    Abstract [en]

    Sprayed concrete differs from ordinary concrete through application technique and addition of set accelerator that gives immediate stiffening. The alkali free set accelerator consists of sulphate and aluminate and forms an ettringite network that gives a stiff but not hard matrix. This work has investigated the interaction between the early ettringite matrix and the proper cement hydration and the development of the interfacial zone between concrete and rock. This has been correlated to the development of the bond strength.

  • 140.
    Lagerblad, Björn
    et al.
    RISE, SP – Sveriges Tekniska Forskningsinstitut, CBI Betonginstitutet AB.
    Cirera Riu, Jaume
    How to evaluate fillers from crushed rock aggregate for concrete production2014In: Nordic Concrete Research, ISSN 0800-6377, Vol. 50, no 2, p. 105-108Article in journal (Refereed)
    Abstract [en]

    In fresh concrete, the filler fraction (0-0.125 mm) is of vital importance for workability. With the use of superplasticizer, it is possible today to use quite large amount of fillers. This has made it possible to make self-compacting concrete and other special concretes. How to use the fillers and the amount of fillers depends on the size distribution and quality of the filler. Basically, the filler should be round and the distribution of filler and cement should be continuous. The size shall not overlap too much with that of the cement. Fillers from crushed rocks consist of minerals and the filler particles depend on the mineralogy and texture of the rock type. This work treats different methods, including paste rheology, to evaluate the quality of the filler fraction. By using good quality filler, it is possible to reduce the amount of cement in concrete

  • 141.
    Lagerblad, Björn
    et al.
    RISE, SP – Sveriges Tekniska Forskningsinstitut, CBI Betonginstitutet AB.
    Fjällberg, Leif
    RISE, SP – Sveriges Tekniska Forskningsinstitut, CBI Betonginstitutet AB.
    Sprutbetong krymper2007In: CBI-nytt, ISSN 0349-2060, no 1, p. 2-3Article in journal (Other academic)
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  • 142.
    Lagerblad, Björn
    et al.
    RISE, SP – Sveriges Tekniska Forskningsinstitut, CBI Betonginstitutet AB.
    Fjällberg, Leif
    Tidig hydratation.: Styrande mekanismer och modell2008Report (Refereed)
    Abstract [sv]

    The early reactions between cement and water are essential for concrete production. The young concrete must for a certain period of time be workable, a period followed by stiffening and a distinct hardening. How to effect the early hydration has long been known but over time new analytic methods and microscopic methods for observation has been developed. This report mainly focuses on the mechanisms and a new model for the mechanisms is formulated. A better understanding is needed to be able to control production and to develop new accelerators. A following report will concentrate on accelerators. _x000D_ _x000D_ Cement hydration is an exothermic reaction, i.e. it releases heat and is thus spontaneous. It is, however, not a simple reaction like mixing of two liquids. A cement grain is a solid particle and when it comes in contact with water a thin layer of hydrates forms at its surface. This layer hinders new water to reach the cement surface, which hinders further hydration, which in turn gives a period when concrete is workable and can be cast. After a certain period of time depending on type of cement temperature etc, a water filled gap forms between the cement grains and the early hydrates. When water again has access to the cement surface a period of intense hydration, the acceleration period, starts and the concrete hardens. To keep the reactions going it is essential that cement reaction products can penetrate the now formed permeable membrane and deposit the hydrates outside this membrane. The next question is the phenomenas regulating the ionic transport through the membrane and what is controlling the speed of transport._x000D_ _x000D_ A hypothesis is formulated where the shell during the acceleration period acts as a permeable membrane. The exothermic reaction together with the demand of electro neutrality during the ion diffusion through the membrane gives a lower pH inside than outside the membrane. The lower pH keeps the silica in ionic form so that it can diffuse out and precipitate as C-S-H on the outside where the pH is higher. If the pH was high inside the shell C-S-H would precipitate at the cement surface and blockade the reactions. The acceleration process decreases when the membrane becomes too thick. _x000D_ _x000D_ The length of the open period is not controlled by the fineness but of the cement phase composition and temperature. It is also controlled by the age of the cement and by energy modification. The start of the acceleration period is also shortened by salts containing alkaline earth metals like Ca, Sr, Ba and by fine grained minerals containing Ca like calcite and wollastonite. The start of the acceleration period can also be shortened by silica compounds but this demands that the silica is easily and fast soluble in the basic pore solutions. _x000D_ _x000D_ The experiments indicate that the dormant period depends on how fast the early shell grows. This is controlled by the reactivity, mainly the composition of the cement and temperature. Accelerators containing Ca or Si ions or ionic complexes precipitate C-S-H on the outside of the shell which in turn gives a faster growth so that it earlier gets the properties to form a permeable membrane. Experiments also show that mechanical attrition at a late stage will prolong the dormant period presumably by damaging the early shell and thus prolong the time to form a permeable membrane. _x000D_ _x000D_ In the experimental part CBI-report 3/08 tests with different salts, nanosilica and different Portland cements were made. The hydration development was studied by isothermal calorimetry, the hydration products by X-ray diffraction, the microstructure by scanning electron microscopy and the setting time with a Vicat apparatus. Also some concrete experiments were made to verify the early concrete strength.

  • 143.
    Lagerblad, Björn
    et al.
    RISE, SP – Sveriges Tekniska Forskningsinstitut, CBI Betonginstitutet AB.
    Gram, Hans Erik
    Cementa AB, Sweden.
    Westerholm, Mikael
    Cementa AB, Sweden.
    Quality of fine materials concrete from production crushed rocks in sustainable2013In: Sustainable Construction Materials and Technologies, International Committee of the SCMT conferences , 2013, article id e182Conference paper (Refereed)
    Abstract [en]

    Crushed rocks are in general more flaky and irregular in shape than natural aggregates. Moreover the crushed rocks give more fine material. Fillers can in combination with superplasticizers be used to expand the paste phase of the concrete and thus be used to lower the cement consumption. To utilize the filler optimally you need to evaluate the filler quality. There are several methods to evaluate the filler. In this article different methods both as regard the material properties and the behavior in mortar and paste tests are compared and evaluated. The analysis shows the importance of understanding the effect of flakiness and the properties of the finest fraction < 10 µm.

  • 144.
    Lagerblad, Björn
    et al.
    RISE, SP – Sveriges Tekniska Forskningsinstitut, CBI Betonginstitutet AB.
    Gram, Hans-Erik
    Cementa AB, Sweden.
    Westerholm, Mikael
    Cementa AB, Sweden.
    Evaluation of the quality of fine materials and filler from crushed rocks in concrete production2014In: Construction and Building Materials, ISSN 0950-0618, E-ISSN 1879-0526, Vol. 67, no A, p. 121-126Article in journal (Refereed)
    Abstract [en]

    Crushed rocks are, in general, more flaky and irregular in shape than natural aggregates. Especially granitic rocks display variable amounts or flaky free micas in the finer fractions when crushed. Moreover, the crushed rocks result in more fine material. Fillers can, in combination with superplasticizers and if the quality is appropriate be used to expand the paste phase of the concrete and thus be used to lower the cement consumption. To utilize the filler optimally one needs to evaluate the filler quality. There are several methods to evaluate the filler. In this article different methods both in regards to the material properties and the behavior in mortar and micro mortar tests are compared and evaluated. The analysis shows the importance of understanding the effect of both the particle shape and flakiness in the fine fractions and the properties of the material in the finest fraction i.e. <10 μm. This is very much related to the mineralogy of the rock.

  • 145.
    Lagerblad, Björn
    et al.
    RISE, SP – Sveriges Tekniska Forskningsinstitut, CBI Betonginstitutet AB.
    Westerholm, Mikael
    Bergkrossmaterial som ballast2008Report (Refereed)
    Abstract [sv]

    Concrete is a product that in the fresh state shall be able to flow and fill a form without segregating. This gives demands on flow properties and workability of the fresh concrete. Between 60 and 70 volume % of concrete consists of aggregate and thus its properties are fundamental for flowability. Presently in Sweden concrete is made from natural glaciofluvial aggregates in sizes less than 8 mm and with stones from local crushed rocks._x000D_ _x000D_ Locally in Sweden there is a lack of good natural aggregates. Moreover, for environmental reasons the government wants to preserve remaining gravel pits especially those in eskers. As a consequence one must find an alternative aggregate. Concrete is a bulk commodity and a cheap building material. Thus it is only crushed rocks that locally and in sufficient amounts can replace natural aggregates. The rock quarries in Sweden are mainly destined to give good coarse aggregate. In this process one also gets fine aggregates but this product is not optimized for concrete production._x000D_ _x000D_ The main problem is thus to replace the natural fine aggregate in a cost effective way with crushed rocks. Fine aggregates from crushed rocks develop other properties than natural aggregates. This is especially the case in Sweden with predominant granitic rocks. As a consequence concrete with crushed fine aggregates must be proportionated differently. The aim of this project has been to find quality criteria for fine aggregates from crushed rocks to be used in concrete and to measure how to improve the properties. Another important aspect is to find systems for quality insurance for continuous concrete production. The tools used are mainly classification of the aggregates to correlate this with rheological properties. Most effort has been put on understanding the influence of different fine material from granitoid rocks falling through the 2-mm sieve. The reason is that it is this material that causes most problems. The results have, however, been correlated against the properties of (0-16 mm) concrete. Material from 16 different rock quarries have been analysed in great detail and some additional ones in less detail. They have been compared with natural glaciofluvial aggregates. All of the material has been studied by petrographic and image analysis, laser sieve, sand equivalent test and methylen blue test._x000D_ _x000D_ The results show that there is a large variation in properties of fine aggregates from the crushed granites. The reason is that granite is regarded as the mineral composition of a family with varying amounts of different minerals and the different granites have different textures. This is reflected especially in the fine material. The finest fractions contain pure minerals and the geometry of these mineral particles is given by the crystallographic form. One mineral that especially hinders the flow is free mica due to its flaky mineral form. Larger particles are normally composed of rock fragments, i.e. several minerals. In which fraction free mineral grains starts to appear depends on the texture of the granitoids. The amount of free mica grains in the fractions below the 0,5 mm sieve varies from almost none to almost 50 %. There may, however, also be problems related to extreme amounts of filler, variation in grading curve, weathering, clay formation and hydrothermal alteration._x000D_ _x000D_ The main method to analyse flow and workability has been different rheometers where one can split between yield stress and plastic viscosity. The yield stress gives the force to set the particle slurry in motion while the plastic viscosity measures the force needed to keep it in motion. Rheological tests on the different material have been conducted on micro mortar (<0.25 mm) mortar (< 2 mm) and concrete (<16 mm). One finds that the properties of the micro mortar strongly influence that of the mortar, which in turn influences that of the concrete. To a certain degree by careful proportioning it is possible to reduce the influence of the fine material but it is not possible to eliminate it. Some of the fine materials from crushed rocks can almost directly replace natural sand while other fine aggregates are very difficult to use in concrete production._x000D_ _x000D_ This work gives a basic understanding of how to characterise fine aggregate (0-2 mm) in such a way that it gives information on how it will affect the rheological properties of concrete. Moreover, it gives information about how to improve the properties and methods for quality control. A major problem is, however, that there is no single test to be used. This work indicates that one must first do a general characterisation and based on this work develop a method or methods for quality assurance that considers the specific properties of the material from the individual stone quarry. _x000D_

  • 146.
    Lagerblad, Björn
    et al.
    RISE, SP – Sveriges Tekniska Forskningsinstitut, CBI Betonginstitutet AB.
    Westerholm, Mikael
    Hållbar övergång till helkross2011In: Betong, ISSN 1101-9190, no 6, p. 39-40Article in journal (Other academic)
  • 147.
    Larsson, Jörgen
    et al.
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Bygg och Mekanik, Tillförlitlighet och Livslängd.
    Schouenborg, Björn
    RISE, SP – Sveriges Tekniska Forskningsinstitut, CBI Betonginstitutet AB.
    Rätt dimensionering av markstensplattor sparar pengar och miljö2014In: Svensk Bergs- och Brukstidning, Vol. 93, no 3, p. ii-Article in journal (Other (popular science, discussion, etc.))
  • 148.
    Lind, Jonas
    RISE, SP – Sveriges Tekniska Forskningsinstitut, CBI Betonginstitutet AB.
    Simanläggningar med "salta bad"2012In: CBI-nytt, ISSN 0349-2060, no 1, p. 2-3Article in journal (Other academic)
    Download full text (pdf)
    FULLTEXT01
  • 149.
    Lindqvist, Jan Erik
    RISE, SP – Sveriges Tekniska Forskningsinstitut, CBI Betonginstitutet AB.
    Ballast står pall mot frost och salt2008In: Betong, ISSN 1101-9190, no 3, p. 43-45Article in journal (Other academic)
  • 150.
    Lindqvist, Jan Erik
    RISE, SP – Sveriges Tekniska Forskningsinstitut, CBI Betonginstitutet AB.
    Historisk utveckling av bruk och bindemedel till murverk i Sverige2013In: Svensk Bergs & Brukstidning, ISSN 0039-6435, Vol. 92, no 4Article in journal (Other academic)
1234567 101 - 150 of 361
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