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  • 1.
    Appelquist, Karin
    et al.
    RISE, SP – Sveriges Tekniska Forskningsinstitut, CBI Betonginstitutet AB.
    Mueller, Urs
    RISE, SP – Sveriges Tekniska Forskningsinstitut, CBI Betonginstitutet AB.
    Utveckling av ett nytt funktionstest för ASR i betong2014In: CBI-nytt, ISSN 0349-2060, no 2, p. 10-11Article in journal (Other academic)
  • 2.
    Appelquist, Karin
    et al.
    RISE - Research Institutes of Sweden, Built Environment, CBI Swedish Cement and Concrete Research Institute.
    Mueller, Urs
    RISE - Research Institutes of Sweden, Built Environment, CBI Swedish Cement and Concrete Research Institute.
    Trägårdh, Jan
    RISE - Research Institutes of Sweden, Built Environment, CBI Swedish Cement and Concrete Research Institute.
    Detection of potential alkali-silica reactivity of aggregates from Sweden2017Conference paper (Other academic)
  • 3.
    Boubitsas, Dimitiros
    et al.
    RISE - Research Institutes of Sweden, Built Environment, CBI Swedish Cement and Concrete Research Institute.
    Tang, Luping
    Chalmers University of Technology, Sweden.
    Fridh, Katja
    Lund University, Sweden.
    Mueller, Urs
    RISE - Research Institutes of Sweden, Built Environment, CBI Swedish Cement and Concrete Research Institute.
    Utgenannt, Peter
    RISE - Research Institutes of Sweden, Built Environment, CBI Swedish Cement and Concrete Research Institute.
    Frost Resistance of Concrete – Experience from Long-Term Field Exposure2018Report (Other academic)
    Abstract [en]

    This report presents the results from a research project financed by Trafikverket, the Swedish Transport Administration, co-financed by Cementa AB.

    The purpose of this project is to investigate concrete specimens exposed to a de-icing salt highway environment at Highway 40 close to Borås after about 20 years. The project work was divided into two parts: Part One for frost resistance of concrete and Part Two for chloride ingress and reinforcement corrosion.

    In Part One, more than 100 types of concrete mixes with different binder types/combinations, water-binder ratios (w/b) and air contents exposed at three field test sites were examined for external and internal frost damage by measurements of the changes in volume of, and in ultrasonic transmission time through, the specimens. Furthermore, some laboratory tests were carried out to supply necessary data for modelling and identify the possible mechanisms causing frost damage.

    The results show clearly that the highway environment is the most aggressive with regard to external frost damage. Further, the results from this study show that the existence of entrained air and the water-binder ratio are the main parameters influencing the resistance of concrete to external salt-frost damage. Furthermore, the concrete mixes with CEM I, CEM I + 5 % silica, CEM II/A-LL, CEM II/A-S and CEM I + 30 % slag as binder with entrained air and a water/binder ratio of 0.4 or below, has good resistance to internal and external frost damage. Results show that concrete containing large amounts of slag as part of the binder (CEM III/B) have the severest scaling, irrespective of its content of entrained air.

    Comparing results from laboratory testing of salt-frost resistance in accordance with SS 13 72 44 (the ‘Slab test’ in CEN/TS 12390-9) with results after nineteen years’ exposure at the highway exposure site shows that the laboratory standard classifies most concrete qualities correctly.

    However, there is an indication that the laboratory test method may overestimate the scaling resistance of concrete containing a medium to high content of slag as part of the binder. This indicates a need to consider a revision of the slab test procedure so that aging processes is better taken into consideration. A somewhat longer preconditioning time with at least partially an increased carbon dioxide content would for example lead to that the effect of carbonation is better reflected.

  • 4. Chozas, V.
    et al.
    Larraza, Í.
    Vera-Agullo, J.
    Williams Portal, Natalie
    RISE, SP – Sveriges Tekniska Forskningsinstitut, CBI Betonginstitutet AB, Betong & Berg.
    Mueller, Urs
    RISE, SP – Sveriges Tekniska Forskningsinstitut, CBI Betonginstitutet AB, Betong & Berg.
    Da Silva, Nelson
    RISE, SP – Sveriges Tekniska Forskningsinstitut, CBI Betonginstitutet AB, Betong & Berg.
    Flansbjer, Mathias
    RISE, SP – Sveriges Tekniska Forskningsinstitut.
    Synthesis and characterization of reactive powder concrete for its application on thermal insulation panels2015In: IOP Conference Series: Materials Science and Engineering, Institute of Physics Publishing (IOPP), 2015, Vol. 96, no 1, article id 012044Conference paper (Refereed)
    Abstract [en]

    This paper describes the synthesis and characterization of a set of textile reinforced reactive powder concrete (RPC) mixes that have been prepared in the framework of the SESBE project which aims to develop facade panels for the building envelope. In order to reduce the environmental impact, high concentration of type I and II mineral additions were added to the mixtures (up to 40% of cement replacement). The mechanical properties of the materials were analysed showing high values of compression strength thus indicating no disadvantages in the compression mechanical performance (∼140 MPa) and modulus of elasticity. In order to enable the use of these materials in building applications, textile reinforcement was introduced by incorporating layers of carbon fibre grids into the RPC matrix. The flexural performance of these samples was analysed showing high strength values and suitability for their further utilization.

  • 5. Falchi, L
    et al.
    Mueller, Urs
    RISE, SP – Sveriges Tekniska Forskningsinstitut, CBI Betonginstitutet AB.
    Influence and effectiveness of water-repellent admixtures on pozzolana-lime mortars for restoration application2013In: Construction and Building Materials, ISSN 0950-0618, E-ISSN 1879-0526, Vol. 49, p. 272-280Article in journal (Refereed)
    Abstract [en]

    Pozzolana-lime mortars modified with water-repellent admixtures were designed and studied to obtain mortars for restoration application. Powdered silane and calcium stearates were mixed with pozzolana, lime and sand and the chemical-physical properties of the resulting mortars were evaluated by X-ray diffraction, electron microscopy (SEM-EDX), thermogravimetric analysis and FT-IR spectroscopy. The mechanical behavior, the pore structure and the hygric behavior were measured. The resistance of water-repellent mortars to the salt crystallization was evaluated. Both calcium stearates and powdered silane allowed good water-repellent protection even if the water-repellent agents and their dosage modified some physical properties and the hydration kinetic.

  • 6. Falchi, Laura
    et al.
    Mueller, Urs
    RISE - Research Institutes of Sweden, Built Environment, CBI Swedish Cement and Concrete Research Institute.
    Fontana, Patrick
    RISE - Research Institutes of Sweden, Built Environment, CBI Swedish Cement and Concrete Research Institute.
    Balliana, Eleonora
    Izzo, Francesca
    Zendri, Elisabetta
    Artificial weathering of water-repellent mortars suitable for restoration applications2014In: Hydrophobe VII / [ed] Mimoso, J.-M., Charola, A.E., 2014Conference paper (Refereed)
  • 7. Falchi, Laura
    et al.
    Zendri, Elisabetta
    Mueller, Urs
    RISE, SP – Sveriges Tekniska Forskningsinstitut, CBI Betonginstitutet AB, Betong & Berg.
    Fontana, Patrick
    The influence of water-repellent admixtures on the behaviour and the effectiveness of Portland limestone cement mortars2015In: Cement & Concrete Composites, ISSN 0958-9465, E-ISSN 1873-393X, Vol. 59, p. 107-118Article in journal (Refereed)
    Abstract [en]

    Abstract Water-repellent mortars were prepared using different hydrophobic compounds as admixtures. Calcium and zinc stearates, silane/siloxane products (as liquid solution and powder) were mixed into limestone cement mortars for obtaining in-bulk water-repellent mortars suitable for building protection and resistant to the degrading action of water. The influences of the admixtures on the hydration and structure of the designed mortars were investigated by SEM, TG–DSC, FT-IR, XRD, and isothermal calorimetry. The effectiveness of these agents against water action was evaluated by using techniques and methods such as mercury intrusion porosimetry, water absorption tests and contact angle measurements. Siloxane products conveyed good water-repellent effectiveness, without strongly influencing the setting and hydration of the binder, while the zinc stearates slowed down the hydration reactions.

  • 8.
    Flansbjer, Mathias
    et al.
    RISE, SP – Sveriges Tekniska Forskningsinstitut.
    Honfi, Daniel
    RISE, SP – Sveriges Tekniska Forskningsinstitut.
    Vennetti, Daniel
    Williams Portal, Natalie
    Mueller, Urs
    RISE, SP – Sveriges Tekniska Forskningsinstitut, CBI Betonginstitutet AB.
    Wlasak, Lech
    Strutural performance of GFRP connectors in Composite sandwich facade elements2016In: Journal of Facade Design and Engineering, Vol. 4, no 1-2, p. 35-52Article in journal (Refereed)
    Abstract [en]

    A systematic testing and modelling program has been developed for the verification of the structural performance of facade sandwich elements to take structural aspects into consideration in the SESBE research project, focusing on the development of “smart” facade elements.

    The present paper mainly focuses on the verification of the mechanical performance of the glass fibre reinforced polymer (GFRP) connectors of the novel type of facade element composed of reactive powder concrete (RPC) panels with foam concrete insulation between them. Because of the reduced thickness of the large facade elements, the performance of the connectors is critical for the entire structural concept. The first series of the testing and modelling programme concerning connector performance are presented here. The results suggest that sufficient strength and ductility of the connectors can be ensured using GFRP in the proposed thin light-weight facade elements.

  • 9.
    Flansbjer, Mathias
    et al.
    RISE, SP – Sveriges Tekniska Forskningsinstitut.
    Honfi, Daniel
    RISE, SP – Sveriges Tekniska Forskningsinstitut.
    Vennetti, Daniel
    RISE, SP – Sveriges Tekniska Forskningsinstitut.
    Williams Portal, Natalie
    RISE, SP – Sveriges Tekniska Forskningsinstitut, CBI Betonginstitutet AB, Betong & Berg.
    Mueller, Urs
    RISE, SP – Sveriges Tekniska Forskningsinstitut, CBI Betonginstitutet AB, Betong & Berg.
    Własak, Lech
    Structural Concept of Novel RPC Sandwich Façade Elements with GFRP Connectors2016In: IABSE Congress Stockholm, 2016: Challenges in Design and Construction of an Innovative and Sustainable Built Environment. Report, IABSE c/o ETH Hönggerberg , 2016, p. 2172-2186Conference paper (Refereed)
    Abstract [en]

    The SESBE research project aims to develop novel smart sandwich façade elements with high insulating capabilities while providing a reduced thickness in conjunction with superior mechanical and durability properties. The present paper mainly focuses on the verification of the mechanical performance of the glass fibre reinforced polymer (GFRP) connectors in the façade element composed of reactive powder concrete (RPC) panels with foam concrete insulation between them. Because of the reduced thickness of the large façade elements, the performance of the connectors is critical for the entire structural concept. A description of structural performance and results based on experimental methods and finite element (FE) analysis are presented.

  • 10.
    Flansbjer, Mathias
    et al.
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Sveriges tekniska forskningsinstitut, SP – Sveriges Tekniska Forskningsinstitut / Hållfasthet (BMh).
    Honfi, Daniel
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Bygg och Mekanik, Strukturer och Komponenter.
    Williams Portal, Natalie
    Mueller, Urs
    Larraza, Inigo
    Edgar, Jan-Olof
    Wlasak, Lech
    Structural behaviour of RPC sandwich façade elements with GFRP connectors2015In: VII International Congress on Architectural Envelopes. San Sebastian-Donostia, Spain. 2015-05-27--29, 2015Conference paper (Other academic)
  • 11.
    Flansbjer, Mathias
    et al.
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Sveriges tekniska forskningsinstitut, SP – Sveriges Tekniska Forskningsinstitut / Hållfasthet (BMh).
    Malaga, Katarina
    RISE, SP – Sveriges Tekniska Forskningsinstitut, CBI Betonginstitutet AB.
    Williams Portal, Natalie
    Dias Ferreira Da Silva, Nelson
    Mueller, Urs
    Larraza, Inigo
    Chozas, Valle
    Vera, Jose
    Reactive powder concrete for facade elements – A sustainable approach2015In: VII International Congress on Architectural Envelopes. San Sebastian-Donostia, Spain. 2015-05-27--29, 2015Conference paper (Other academic)
  • 12.
    Flansbjer, Mathias
    et al.
    RISE, SP – Sveriges Tekniska Forskningsinstitut.
    Mueller, Urs
    RISE, SP – Sveriges Tekniska Forskningsinstitut, CBI Betonginstitutet AB.
    Williams Portal, Natalie
    Chozas, Valle
    Larraza, Inigo
    Dias Ferreira Da Silva, Nelson
    Malaga, Katarina
    RISE, SP – Sveriges Tekniska Forskningsinstitut, CBI Betonginstitutet AB.
    Reactive powder concrete for facade elements: A sustainable approach2016In: Journal of Facade Design and Engineering, Vol. 4, no 1-2, p. 53-66Article in journal (Refereed)
    Abstract [en]

    Reactive powder concrete (RPC) is a fairly novel material with extraordinary strength and durability properties. Due to these properties, it is increasingly being utilized for external fa¸cade cladding thus enabling a considerable reduction in the thickness of concrete elements. Commercial RPC formulations on the market are usually expensive and less sustainable due to high cement clinker contents. In this study, improved RPC formulations with higher amounts of supplementary cementitious materials (SCMs) were developed. The formulations were combined with different types of reinforcements ranging from steel fibres to fibre textile grids primarily to enhance the ductility and tensile strength of the composite material. The results showed that even with clinker replacement levels of up to ca. 40% of the total binder amount, a satisfactory mechanical performance of the RPC mixes could still be achieved. A fairly steep strength gain rendered heat treatment unnecessary. The materials displayed good flow properties and a reasonably short initial setting time. The incorporation of carbon textile fibre grids proved to be highly effective in improving the post cracking behaviour of the RPC. The results validated a more sustainable approach for RPC applied to thin fa¸cade elements. 

  • 13.
    Flansbjer, Mathias
    et al.
    RISE - Research Institutes of Sweden, Safety and Transport, Safety.
    Williams Portal, Natalie
    RISE - Research Institutes of Sweden, Safety and Transport, Safety.
    Vennetti, Daniel
    RISE - Research Institutes of Sweden, Safety and Transport, Safety.
    Mueller, Urs
    RISE - Research Institutes of Sweden, Built Environment, CBI Swedish Cement and Concrete Research Institute.
    Composite Behaviour of Textile Reinforced Reactive Powder Concrete Sandwich Façade Elements2018In: International Journal of Concrete Structures and Materials, ISSN 1976-0485, E-ISSN 2234-1315, Vol. 12, no 1, article id 71Article in journal (Refereed)
    Abstract [en]

    Within the EC funded project smart elements for sustainable building envelopes, carbon textile reinforcement was incorporated into reactive powder concrete, namely textile reinforced reactive powder concrete (TRRPC), to additionally improve the post-cracking behaviour of the cementitious matrix. This high-performance composite material was included as outer and inner façade panels in prefabricated and non-load bearing sandwich elements along with low density foamed concrete (FC) and glass fibre reinforced polymer continuous connecting devices. Experiments and finite element analysis (FEA) were applied to characterize the structural performance of the developed sandwich elements. The mechanical behaviour of the individual materials, components and large-scale elements were quantified. Four-point bending tests were performed on large-scale TRRPC-FC sandwich element beams to quantify the flexural capacity, level of composite action, resulting deformation, crack propagation and failure mechanisms. Optical measurements based on digital image correlation were taken simultaneously to enable a detailed analysis of the underlying composite action. The structural behaviour of the developed elements was found to be highly dependent on the stiffness and strength of the connectors to ensure composite action between the two TRRPC panels. As for the FEA, the applied modelling approach was found to accurately describe the stiffness of the sandwich elements at lower load levels, while describing the stiffness in a conservative manner after the occurrence of connector failure mechanisms. © 2018, The Author(s).

  • 14.
    Helsing, Elisabeth
    et al.
    RISE - Research Institutes of Sweden, Built Environment, CBI Swedish Cement and Concrete Research Institute.
    Parg, Lisa
    RISE - Research Institutes of Sweden, Built Environment, CBI Swedish Cement and Concrete Research Institute.
    Mueller, Urs
    RISE - Research Institutes of Sweden, Built Environment, CBI Swedish Cement and Concrete Research Institute.
    Ellison, Tommy
    BESAB, Sweden.
    Hydrofoberande medel i sprutbetong: Inverkan på egenskaper och beteendet vid sprutning2017Report (Other academic)
    Abstract [en]

    The overall goal with this project is to acquire more profound knowledge and experiences as regards the use of hydrophobic agents added to fresh concrete (hydrophobic admixtures) intended for sprayed concrete with low-alkali binders, with the purpose to enhance the durability and serviceability of the sprayed concrete. The results from this project contribute to increased understanding of the practical possibilities with and limitations for hydrophobic admixtures in sprayed concrete. Thus the need for costly field tests, with trial and error can be decreased.A large part of the project has been devoted to study the influence of the hydrophobic admixtures on the properties at an early stage, since these are decisive for the practical application. In addition the influence on strength development and bond have been determined. The hydrophobicity that these admixtures give the concrete has also been investigated. These tests have primarily been carried out on paste, mortar or concrete cast in a traditional way, not on sprayed concrete. Spraying tests have been carried out with one of the hydrophobic admixtures and a reference without admixture in order to study the behaviour at spraying. On samples from the sprayed concrete the bond, hydrophobicity and chloride intrusion have been determined.Two hydrophobic admixtures, Sitren P 750 (E) and Silres BS 1001 (W) have been used, both based on organosilicates. Admixture E consist of a modified siloxan which is attached to silica fume and admixture W is a water based emulsion of silan/siloxan. Most of the tests were carried out on a pure Portland cement (Degerhamns Anläggningscement from Cementa) and on a Portland-fly ash cement (Slite Anläggning FA from Cementa). Both cements are sulphate resistant and have low alkali content. Tests with and without accelerator have been carried out.When used without accelerator admixture W influenced the setting time and the heat development much more than admixture E. Admixture W had a clear retarding effect. It was though possible to compensate for this effect by adding an accelerator. The 28 day strength decreased when both admixtures were used, most with admixture W. But also in this case this effect was to some extent compensated by adding an accelerator. The accelerator did not have a decisive influence when admixture E was used. When the bond was determined on cast concrete admixture W gave higher and less deviating results than admixture E. The hydrophobicity in mixtures with the two admixtures was comparable.The spray test was carried out with admixture W and an accelerator. With the admixture less water was needed to give the same workability. The behaviour at spraying was as good as, or somewhat better, with the hydrophobic admixture compared to the mix without. The hydrophobic admixture did not influence the bond of the sprayed concrete. The water absorption of the sprayed concrete with the hydrophobic admixture was approximately 30 % lower than without, and the resistance to chloride intrusion was approximately 40 % higher.

  • 15.
    Hesselgren, Lars
    et al.
    PLP Architecture, Sweden.
    Andreasson, Ingemar
    LogistikCentrum, Sweden.
    Mueller, Urs
    RISE - Research Institutes of Sweden, Built Environment, CBI Swedish Cement and Concrete Research Institute.
    Prieto Rábade, Miguel
    RISE - Research Institutes of Sweden, Built Environment, CBI Swedish Cement and Concrete Research Institute.
    Janhäll, Sara
    RISE - Research Institutes of Sweden, Built Environment, Energy and Circular Economy.
    NuMo – New Urban Mobility: New urban infrastructure support for autonomous vehicles2019Report (Other academic)
    Abstract [en]

    Foreword All transport systems have a certain capacity determined by its configurations. For cars the most efficient current form is constant speed driving, e.g. the motorway. Its capacity is limited by the time separation between vehicles. Any transport system that stops because of congestion or other causes by definition sees its capacity reduced to zero. Hence traffic jams are hugely disruptive. Public transport operates on a model inherited from the 19 th Century. Vehicles (buses, trams, railways, metros) run on a regular (timetabled) basis and stops at every station (bus stop). Since there is no pre-booking and the need of transport is hard to foresee, the vehicles are often almost empty, at other times hugely congested. The NuMo technology emerges from decades of work across the whole transportation industry. Autonomous electric vehicles (AEVs) equipped with vehicle-to-vehicle (V2V) communication can safely keep shorter distances. In practical terms this means that a platooned car system has the same capacity in one lane as a double-lane motorway. Automated intelligent controls ensure that the NuMo systems never stops, thus achieving the highest capacity. Instead of waiting for the mass deployment of fully automated vehicles, NuMo starts with dedicated networks that integrate tightly with existing infrastructure for step-wise smooth transition to fully automated transport system. NuMo includes an on-demand public transport system which only runs when it is needed. The system will take advantage of close-spacing possible with robot controls – vehicles can run close together and also use less road width by less wiggling. Equally importantly stations and access to the normal road network is arranged such that the traffic flow never stops. The urban impact can be imagined by understanding the impact of modern public transport systems currently under construction. Some of them are underground to avoid disrupting the street patterns. Some are elevated, some rely on physical separation at grade. One interesting option is to use tunnels underground or in water to further reduce disruption. Many cities are abandoning the traditional port infrastructure giving huge opportunities to again regard water as a connector rather than something to cross. The NuMo system uses all of those techniques and detailed design studies are under way for each of those options. NuMo will make an important contribution to environmental sustainability in many respects. Firstly, it will accelerate adoption of electric propulsion; secondly it will encourage vehicle sharing; and thirdly by only running when needed will save on unnecessary movements and finally its construction costs will be less than conventional systems. Sketches of NuMo networks are presented on places as diverse as Stockholm, Gothenburg and New York. Naturally the system will also be crucial in the development of new cities. This report is a summary of the studies performed within the project “New urban infrastructure support for autonomous vehicles” financed by Vinnova through the Strategic Innovation Program InfraSweden2030. The aim is to explore the infrastructure support to accelerate the introduction of autonomous electric vehicles for future mobility.

  • 16. 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.

  • 17.
    Lundgren, Monica
    et al.
    RISE - Research Institutes of Sweden, Built Environment, CBI Swedish Cement and Concrete Research Institute.
    Babaahmadi, Arezou
    RISE - Research Institutes of Sweden, Built Environment, CBI Swedish Cement and Concrete Research Institute.
    Mueller, Urs
    RISE - Research Institutes of Sweden, Built Environment, CBI Swedish Cement and Concrete Research Institute.
    Exposure experiments in sulfate containing solution, including exposure at low temperature2018Report (Other academic)
    Abstract [en]

    This report describes results of an investigation on the sulfate resistance of dual blended binder of mortar and concrete specimens over a period of 1 year. The focus is on showing the importance of the chemistry of the components when discussing sulfate resistance and the relation of that to the hydrate phase assemblage. Moreover the importance of the test method for evaluations is pointed out.

  • 18.
    Lundgren, Monica
    et al.
    RISE - Research Institutes of Sweden, Built Environment, CBI Swedish Cement and Concrete Research Institute.
    Helsing, Elisabeth
    RISE - Research Institutes of Sweden, Built Environment, CBI Swedish Cement and Concrete Research Institute.
    Babaahmadi, Arezou
    RISE - Research Institutes of Sweden, Built Environment, CBI Swedish Cement and Concrete Research Institute.
    Mueller, Urs
    RISE - Research Institutes of Sweden, Built Environment, CBI Swedish Cement and Concrete Research Institute.
    State-of-the-Art Report on: Material Type, Requirements and Durability aspects of Sprayed Concrete in Tunnels2018Report (Other academic)
    Abstract [en]

    The report summarizes a state-of-the-art for sprayed concrete applied for ground support in tunnel environments, in Sweden and several European countries, with focus on the components, the mix design and the guidelines and specifications. It focuses also on the addition of supplementary cementitious materials (SCM), where the use, the common practice and the long-term experience vary from country to country. The report presents numerous examples of applications in Sweden and seven other European countries. It also gives an overview about the possible exposure risks and summarizes the relevant durability issues. Along with specifications in international standards and guidelines it also reviews the national requirements in Sweden, Norway, Finland, Austria, France, Germany and Switzerland.

  • 19.
    Malaga, Katarina
    et al.
    RISE, SP – Sveriges Tekniska Forskningsinstitut, CBI Betonginstitutet AB.
    Mueller, Urs
    RISE, SP – Sveriges Tekniska Forskningsinstitut, CBI Betonginstitutet AB.
    Relevance of hydrophobic and oleophobic properties of antigraffiti systems on their cleaning efficiency on concrete and stone surfaces2013In: Journal of materials in civil engineering, ISSN 0899-1561, E-ISSN 1943-5533, Vol. 25, no 6, p. 755-762Article in journal (Refereed)
    Abstract [en]

    The problem of graffiti is not entirely restricted to urban areas, but also appears frequently in rural communities and along traffic infrastructure. Besides its aesthetic and societal effects, graffiti cause considerable removal costs and subsequent costs for repairing damages caused by improper graffiti removal. Over the last two decades, strategies have been developed to combat graffiti in the built environment, including the development of protective measures in the form of antigraffiti systems (AGSs). Antigraffiti systems promise to be affordable and easily applicable for a wide range of substrates, and many products have already been on the market for many years. In practice, however, successful application of AGS and removal of graffiti depend on many factors in which the type of coating and condition of the substrate play critical roles. The optimal environmental goal is to use AGS without any cleaning chemicals except for pure water. Available studies on the behavior of the same AGS on various substrates can show completely different results concerning the cleaning efficacy and the durability of the AGS under different climatic conditions. The question of which properties of an AGS are most essential for its efficiency has still not been fully investigated. The goal of this study was to investigate cleaning efficacy in conjunction with hydrophobic and oleophobic properties of the AGS on different substrates. The results showed that hydrophobicity and oleophobicity are important for dense substrates but have a low influence on porous substrates. In this case, cleaning efficiency is majorly determined by the physical properties of the substrates.

  • 20. Meng, Birgit
    et al.
    Fontana, Patrick
    RISE - Research Institutes of Sweden, Built Environment, CBI Swedish Cement and Concrete Research Institute.
    Mueller, Urs
    RISE - Research Institutes of Sweden, Built Environment, CBI Swedish Cement and Concrete Research Institute.
    Bürgisser, Philip
    Influence of natural pozzolans on the risk of Alkali Silica Reaction2013In: International Conference on Advances in Cement and Concrete Technology in Africa, BAM Federal Institute for Materials and Testing , 2013, p. 801-808Conference paper (Refereed)
  • 21. Meng, Birgit
    et al.
    Mueller, Urs
    RISE, SP – Sveriges Tekniska Forskningsinstitut, CBI Betonginstitutet AB.
    Performance of a new anti-graffiti agent used for immovable cultural heritage objects2014In: International Journal of Architectural Heritage, ISSN 1558-3058, E-ISSN 1558-3066, Vol. 8, no 6, p. 820-834Article in journal (Refereed)
    Abstract [en]

    Cultural Heritage objects are in many cases invaluable and irrecoverable, therefore their protection is a major goal. One threat arises by intentionally defacing such objects with graffiti. One possibility to face the imminent threat is the application of a surface protection in form of anti-graffiti systems (AGS). However, the knowledge about the performance and durability of AGS on substrates used for historical buildings is still fragmented. The goal of the present study was to investigate the performance of a newly developed anti-graffiti agent in comparison to a selection of commercial anti-graffiti agents on different substrates that were used for historical buildings. Four commercial anti-graffiti agents with different chemical formulations were selected and tested with the new agent on different stone and brick substrates. The results showed clearly that AGS based on dense, water-vapor impermeable coatings are not suitable to porous substrates such as sandstone, brick, or porous limestone due to their impairment of the hygric properties and the visual appearance of a substrate. The new agent could not completely reach the cleaning efficacy of the dense coatings but exhibited a much lower impact on the properties of the substrate and was therefore better compatible to historical surfaces.

  • 22. Miccoli, L.
    et al.
    Drougkas, A.
    Mueller, Urs
    RISE, SP – Sveriges Tekniska Forskningsinstitut, CBI Betonginstitutet AB, Betong & Berg.
    In-plane behaviour of rammed earth under cyclic loading: Experimental testing and finite element modelling2016In: Engineering structures, ISSN 0141-0296, E-ISSN 1873-7323, Vol. 125, p. 144-152Article in journal (Refereed)
    Abstract [en]

    The purpose of this paper is to numerically simulate the in-plane behaviour of rammed earth walls under cyclic shear-compression tests. The experimental testing allowed obtaining the maximum horizontal loads, the displacement capacity and the level of non-linear behaviour of the respective load-displacement relationships as well as the failure modes. The calibration of the numerical model (finite element method) was carried out based on the experimental results. Within this framework, a micro-modelling approach was considered. The behaviour of the rammed earth material was simulated using a total strain rotating crack model. A Mohr-Coulomb failure criterion was used to reproduce the behaviour of the interfaces between the layers. Although the numerical results achieved a satisfactory agreement with the experimental results a sensitivity analysis of the parameters involved was performed. The sensitivity analysis aimed at determining which parameters of the model have a significant impact in the model's results. As expected the sensitivity analysis pointed out that the sliding failure occurrence is mainly influenced by two parameters of the interface elements: the interface tensile strength fit and the friction angle φ. Moreover the cohesion c and the layers thickness showed a limited effect on the shear behaviour. It should be noted that the results mentioned above are related to the cases where a significant level of vertical compressive stress σ is employed.

  • 23. Miccoli, L.
    et al.
    Fontana, P.
    Johansson, Gabriel
    RISE, SP – Sveriges Tekniska Forskningsinstitut, CBI Betonginstitutet AB, Tillståndsbedömningar.
    Zandi, Kamyab
    RISE, SP – Sveriges Tekniska Forskningsinstitut, CBI Betonginstitutet AB, Betong & Berg.
    Williams Portal, Natalie
    RISE, SP – Sveriges Tekniska Forskningsinstitut, CBI Betonginstitutet AB, Betong & Berg.
    Mueller, Urs
    RISE, SP – Sveriges Tekniska Forskningsinstitut, CBI Betonginstitutet AB, Betong & Berg.
    Numerical modelling of UHPC and TRC sandwich elements for building envelopes2015In: IABSE Conference, Geneva 2015: Structural Engineering: Providing Solutions to Global Challenges - Report, IABSE , 2015, p. 195-203Conference paper (Refereed)
    Abstract [en]

    In this paper a modelling approach is presented to reproduce the mechanical behaviour of sandwich panels via finite element analysis. Two types of panels were investigated in this scope of work. The first sandwich element was a textile reinforced concrete (TRC) panel with cellular lightweight concrete insulation and the second configuration was an ultra-high performances concrete (UHPC) panel with aerated autoclaved concrete insulation. The goal was to obtain a reliable numerical strategy that represents a reasonable compromise in terms of sufficient accuracy of the element characteristics and the computational costs. The results show the possibility of describing the composite action in a full sandwich panel. The achieved modelling approach will later be used for the optimization of TRC and UHPC panels in terms of minimizing the thickness, identifying the number and location of connectors, as well as evaluating varying anchorage systems.

  • 24. Miccoli, L.
    et al.
    Garofano, A.
    Fontana, P.
    Mueller, Urs
    RISE, SP – Sveriges Tekniska Forskningsinstitut, CBI Betonginstitutet AB, Betong & Berg.
    Experimental testing and finite element modelling of earth block masonry2015In: Engineering structures, ISSN 0141-0296, E-ISSN 1873-7323, Vol. 104, p. 80-94Article in journal (Refereed)
    Abstract [en]

    The current paper focuses on the determination of reliable numerical models of earth block masonry wallettes under different loading conditions. Uniaxial compression and diagonal compression tests were performed. Experimental behaviour was modelled with a non-linear model able to describe the cracking behaviour. The simplified approach based on macro-modelling shows a satisfactory accuracy and low computational costs. The results reproducing the uniaxial compression are in good correspondence with the post-elastic behaviour observed in the experimental campaign. The micro-modelling approach adopted to reproduce the shear behaviour, even with high computational cost, represents a suitable tool to predict the masonry collapse mechanism.

  • 25. Miccoli, L
    et al.
    Mueller, Urs
    RISE, SP – Sveriges Tekniska Forskningsinstitut, CBI Betonginstitutet AB.
    Mechanical behaviour of earthen materials.: A comparison between earth block masonry, rammed earth and cob2014In: Construction and Building Materials, ISSN 0950-0618, E-ISSN 1879-0526, Vol. 61, p. 327-339Article in journal (Refereed)
    Abstract [en]

    Earth represents one of the oldest construction materials, which is still utilised both in developed and in developing countries. In this paper a comparison of the mechanical performance of structural elements built in three basic techniques, earth block (adobe) masonry, rammed earth and cob, is presented. In order to gain better knowledge on the structural behaviour under static loads an extensive compression and diagonal compression (shear) test campaign was performed. First compression results showed brittle mechanical behaviour in the case of earth block masonry and rammed earth elements, whereas cob exhibited a very different stress-strain pattern: cob can deform beyond the elastic range with a gradual drop in capacity. Despite its low compressive strength, cob thus presents a relatively good performance within the earthen material range as far as shear behaviour is concerned. The data here reported represents a base for a further investigation on the dynamic behaviour of the three materials considered. The study was carried out within the framework of the project NIKER funded by the European Commission dealing with improving immovable Cultural Heritage assets against the risk of earthquakes.

  • 26. Miccoli, Lorenzo
    et al.
    Fontana, Patrick
    RISE - Research Institutes of Sweden, Built Environment, CBI Swedish Cement and Concrete Research Institute.
    Ziegert, C
    Perrone MEng, Chiara
    Mueller, Urs
    RISE - Research Institutes of Sweden, Built Environment, CBI Swedish Cement and Concrete Research Institute.
    Charakterisierung und Modellierung der mechanischen Eigenschaften von Lehmsteinmauerwerk - Mechanical Characterization and modelling of earth block masonry2012In: Mauerwerk, Vol. 16, no 6, p. 279-292Article in journal (Refereed)
    Abstract [en]

    Knowledge of the material properties and failure mechanisms of earthen materials is limited and scattered. Within the framework of the NIKER project (www.niker.eu) funded by EC, the mechanical properties of earthen material elements were therefore determined under static compression and shear loads. The aim was to obtain fundamental data on deformation behaviour and failure mechanisms of earthen material structural elements and to describe them by means of a numerical model. The test results confirmed the brittle behaviour of earth block masonry under monoaxial compressive load and showed that the failure of earth block masonry under shear load occurs by sliding of the earth blocks along the mortar joints after initial cracking in mortar joints and earth block. Numerical macro modelling showed satisfying results with regard to stress‐strain behaviour, but the simulated crack pattern was not consistent with experimental observations. In the case of earth block masonry, it is thus necessary to use micro modelling approaches in order to correctly predict the failure process at local level.

  • 27. Miccoli, Lorenzo
    et al.
    Fontana, Patrick
    RISE - Research Institutes of Sweden, Built Environment, CBI Swedish Cement and Concrete Research Institute.
    Ziegert, Christof
    Perrone, Chiara
    Mueller, Urs
    RISE - Research Institutes of Sweden, Built Environment, CBI Swedish Cement and Concrete Research Institute.
    Charakterisierung und Modellierung der mechanischen Eigenschaften von Lehmsteinmauerwerk - Mechanical Characterization and Modelling of Earth Block Masonry2012In: Masonry, ISSN 1432-3427, E-ISSN 1437-1022, Vol. 16, no 6, p. 279-292Article in journal (Refereed)
  • 28. Miccoli, Lorenzo
    et al.
    Garofano, Angelo
    Fontana, Patrick
    RISE - Research Institutes of Sweden, Built Environment, CBI Swedish Cement and Concrete Research Institute.
    Mueller, Urs
    RISE - Research Institutes of Sweden, Built Environment, CBI Swedish Cement and Concrete Research Institute.
    Static behaviour of earth block masonry: experimental testing and Finite Element Modelling2014In: 9th International Masonry Conference (IMC), Guimarães, Portugal, 2014Conference paper (Other academic)
  • 29.
    Miccoli, Lorenzo
    et al.
    BAM Bundesanstalt für Materialforschung und –prüfung, Germany.
    Mueller, Urs
    RISE - Research Institutes of Sweden, Built Environment, CBI Swedish Cement and Concrete Research Institute.
    Pospíšil, Stanislav
    Institute of Theoretical and Applied Mechanics, Czech Republic.
    Rammed earth walls strengthened with polyester fabric strips: Experimental analysis under in-plane cyclic loading2017In: Construction and Building Materials, ISSN 0950-0618, E-ISSN 1879-0526, Vol. 149, p. 29-36Article in journal (Refereed)
    Abstract [en]

    This study analyses the mechanical behaviour under pseudo-dynamic loading of structural elements built in rammed earth and strengthened with polyester fabric strips. This strengthening technique was developed to exploit the strength potential of rammed earth and to solve its lack of tensile strength. For this reason, in-plane cyclic tests were carried out to investigate the shear behaviour of unstrengthened and strengthened walls. The strengthening technique requires low-tech equipment and workmanship, uses readily available, not expensive and industrially standardised materials. The experimental results were analysed in terms of stiffness degradation, energy dissipation capacity and equivalent viscous damping. Although the unstrengthened and strengthened walls confirmed a limited ductile behaviour, the findings confirm that the strengthening contributes to limit the spread of the diagonal cracks and provide an increase of strength in terms of horizontal load and displacement capacity.

  • 30.
    Miccoli, Lorenzo
    et al.
    Bundesanstalt für Materialforschung und -prüfung, Germany.
    Silva, Rui
    University of Minho, Portugal.
    Oliveira, Daniel
    University of Minho, Portugal.
    Mueller, Urs
    RISE - Research Institutes of Sweden, Built Environment, CBI Swedish Cement and Concrete Research Institute.
    Static behavior of cob: Experimental testing and finite-element modeling2019In: Journal of materials in civil engineering, ISSN 0899-1561, E-ISSN 1943-5533, Vol. 31, no 4, article id 04019021Article in journal (Refereed)
    Abstract [en]

    The aim of this paper is to implement a numerical model to reproduce the nonlinear behavior of cob walls under shear loading. Axial compression, pull-off, and diagonal compression tests were carried out to derive the mechanical parameters. In addition, the stressstrain relationships, the nonlinear behavior, and the failure modes were defined. The experimental results were then used to calibrate a finiteelement model. The material behavior was simulated through a macromodeling approach adopting the total strain rotating crack model. A sensitivity analysis was conducted to assess the effects of varying the parameters with higher uncertainty on the structural behavior. The numerical model achieved good correspondence with the experimental results in terms of simulation of the shear stress-shear strain relationship and of damage pattern.

  • 31.
    Mueller, Urs
    RISE, SP – Sveriges Tekniska Forskningsinstitut, CBI Betonginstitutet AB.
    Internationella och nationella kommittéer om ASR i betong2014In: CBI-nytt, ISSN 0349-2060, no 2, p. 11-Article in journal (Other academic)
  • 32.
    Mueller, Urs
    RISE, SP – Sveriges Tekniska Forskningsinstitut, CBI Betonginstitutet AB.
    Mechanical behaviour of earthen materials: A comparison between earth block masonry, rammed earth and cob2014In: Construction and Building Materials, ISSN 0950-0618, E-ISSN 1879-0526, Vol. 61, p. 327-339Article in journal (Refereed)
  • 33.
    Mueller, Urs
    RISE - Research Institutes of Sweden, Built Environment, CBI Swedish Cement and Concrete Research Institute.
    The mineralogical composition of sandstone and its effect on sulphur dioxide deposition2008In: Materiales de Construcción, Vol. 58, no 289-290, p. 81-95Article in journal (Refereed)
    Abstract [en]

    Air pollutants often accelerate stone deterioration in historical buildings and monuments in urban areas. The pollutants are themselves the products of fossil fuel combustion and intensive farming. While this trend seems to have been curbed by strict emission laws in the European Union, in most developing and emerging countries air pollution is an ongoing process due to increasing energy needs and vehicle traffic. Many factors condition natural stone behaviour with respect to gaseous pollutants. Two of the more prominent of such factors are the composition of the atmosphere and the type of stone. Due to their porosity, sandstones are particularly vulnerable to air pollutant attack. Many of the reactions between non-carbonaceous sandstones and these gases are not well understood, however. The present study aimed to acquire an understanding of the processes and factors governing sandstone behaviour when exposed to sulphur dioxide. Seven different sandstones from southern and eastern Germany were analyzed for the study. The binder composition of the stones varied significantly. They also exhibited completely different behaviour in connection with SO 2 sorption. Interestingly, while the amount of SO 2 deposited was unrelated to the specific surface area of the sandstones, this parameter was closely correlated to the iron oxide content. Iron oxide phases are believed to act as a catalyst in the oxidation of SO 2 to SO 3 . The type and amount of clay mineral, in turn, was found to have no significant impact on initial SO 2 deposition in sandstones.

  • 34.
    Mueller, Urs
    et al.
    RISE, SP – Sveriges Tekniska Forskningsinstitut, CBI Betonginstitutet AB.
    Lundgren, Monica
    RISE, SP – Sveriges Tekniska Forskningsinstitut, CBI Betonginstitutet AB.
    Cement med tillsatsmaterial och risken för ASR i betong2014In: CBI-nytt, ISSN 0349-2060, no 2, p. 5-Article in journal (Other academic)
  • 35.
    Mueller, Urs
    et al.
    RISE - Research Institutes of Sweden, Built Environment, CBI Swedish Cement and Concrete Research Institute.
    Lundgren, Monica
    RISE - Research Institutes of Sweden, Built Environment, CBI Swedish Cement and Concrete Research Institute.
    Babaahmadi, Arezou
    RISE - Research Institutes of Sweden, Built Environment, CBI Swedish Cement and Concrete Research Institute.
    Hydration of concrete binders blended with ground granulated blast furnace slag, fly ash and metakaolin2017Report (Other academic)
    Abstract [en]

    This report describes a study on the effects of ground granulated blast furnace slag, low calcium fly ash and metakaolin on the hydration behavior of different binder pastes blended with these SCM. The study investigated early heat development, phase assemblages at different ages, strength gain, changes in porosity and pore sizes, pore water OH-concentration, development of the microstructure and the micro chemistry of the binder pastes.It was shown that all SCM impact the pore size distribution of pastes of different ages. Compared to a reference paste without SCM, SCM containing pastes shift their pore size range to smaller sizes, the more SCM the pastes contain. The total porosity depends on the type of SCM. With slag, there was a tendency to decrease the total porosity with increasing SCM content. With fly ash, total porosity was increased with increasing fly ash content. The strength development of slag and fly ash containing mortars is under that of a Portland cement reference mortar within the first 28 days. However, after 28 d strength gain, in particular with fly ash is considerable compared to the reference. With metakaolin already at early ages a strong increase in strength was observed. After that, the strength development was parallel the one of the reference mortar. Aluminum containing SCM contribute to the formation of AFm phases. AFm phases increase the chloride binding in seawater or deicing salt exposed concretes. In particular metakaolin and fly ash contribute, due to their high alumina content, to the formation of AFm phases but also increase the aluminum content in the C-S-H phases.

  • 36.
    Mueller, Urs
    et al.
    RISE - Research Institutes of Sweden, Built Environment, CBI Swedish Cement and Concrete Research Institute.
    Lundgren, Monica
    RISE - Research Institutes of Sweden, Built Environment, CBI Swedish Cement and Concrete Research Institute.
    Malaga, Katarina
    RISE - Research Institutes of Sweden, Built Environment, CBI Swedish Cement and Concrete Research Institute.
    Development of pore structure and hydrate phases of binder pastes blended with slag, fly ash and metakaolin – A comparison2015In: The 14th International Conress on the Chemistry of Cement, 2015Conference paper (Refereed)
  • 37.
    Mueller, Urs
    et al.
    RISE - Research Institutes of Sweden, Built Environment, CBI Swedish Cement and Concrete Research Institute.
    Malaga, Katarina
    RISE - Research Institutes of Sweden, Built Environment, CBI Swedish Cement and Concrete Research Institute.
    Influence of hydrophobicity and oleophobicity on cleaning graffiti on concrete panels and natural stones2012In: Concrete Repair, Rehabilitation and Retrofitting III (ICCRRR), TAYLOR and FRANCIS GROUP, LONDON, UK , 2012, p. 269-275Conference paper (Refereed)
    Abstract [en]

    Anti-Graffiti Systems (AGS) are meant to make the cleaning process more efficient by inserting a layer between the paint and the substrate. This layer can have a low surface energy thus make it difficult for the paint to stick to the substrate or it may be easily removed together with the paint. This paper is presenting results from a study of how hydrophobicity and oleophobicity influence the cleaning efficiency of graffiti paints from concrete and natural stones. The results demonstrated that high hydrophobicity and high oleophobicity are not guaranteeing satisfying cleaning effects. The physical properties of a substrate in combination with the characteristics of the AGS layer decide about the cleaning effect.

  • 38.
    Mueller, Urs
    et al.
    RISE, SP – Sveriges Tekniska Forskningsinstitut, CBI Betonginstitutet AB, Betong & Berg.
    Miccoli, L.
    Fontana, P.
    Development of a lime based grout for cracks repair in earthen constructions2016In: Construction and Building Materials, ISSN 0950-0618, E-ISSN 1879-0526, Vol. 110, p. 323-332Article in journal (Refereed)
    Abstract [en]

    The study presents the results from the development of a grouting material based on hydrated lime with addition of pozzolana, which is referred to as hydraulic lime, suitable for the repair of cracks in a variety of earthen building techniques. The goal was to develop a material also compatible with earthen structures exposed to dynamic loads. The grouting mortar was designed to be adaptable in strength properties and at the same time to have sufficient robustness for preparation and use on the construction site. Results showed a satisfactory performance of the grout concerning fresh and hardened mortar properties as well as injectability.

  • 39.
    Mueller, Urs
    et al.
    RISE - Research Institutes of Sweden, Built Environment, CBI Swedish Cement and Concrete Research Institute.
    Rübner, Katrin
    The microstructure of concrete made with municipal waste incinerator bottom ash as an aggregate component2006In: Cement and Concrete Research, Vol. 36, no 8, p. 1434-1443Article in journal (Refereed)
    Abstract [en]

    The interaction of municipal solid waste incinerator bottom ash (MSWI bottom ash), when utilized as an aggregate in concrete, with the cement matrix was investigated. The most prominent reaction observed in lab and field concrete was the formation of aluminium hydroxide and the release of hydrogen gas from aluminium grains reacting in the alkaline environment. The expansive aluminium reaction was identified as a main cause of extensive spalling on the concrete surface. Due to the higher content of bottle glass as part of the ash, in all samples, reaction products of an alkali-silica reaction (ASR) could be observed as well. However, damage due to ASR were less severe than those caused by the aluminium reaction. The expansion rates were low and only a few of the lab samples showed cracking. Microstructural analysis of the samples indicated clearly that a large quantity of the alkali-silica gel which was formed was accommodated in the pores and voids without exerting any strain on the material.

  • 40.
    Mueller, Urs
    et al.
    RISE - Research Institutes of Sweden, Built Environment, CBI Swedish Cement and Concrete Research Institute.
    Schlegel, Moriz-Caspar
    Emmerling, Franziska
    Malaga, Katarina
    Novel techniques for studying damage mechanisms of cementitious matrices affected by sulphate attack2012In: fib symposium Concrete Structures for Sustainable Community / [ed] Bager, D.H., Silfwerbrand, J., 2012, p. 267-270Conference paper (Refereed)
  • 41.
    Mueller, Urs
    et al.
    RISE, SP – Sveriges Tekniska Forskningsinstitut, CBI Betonginstitutet AB.
    Selander, Anders
    RISE, SP – Sveriges Tekniska Forskningsinstitut, CBI Betonginstitutet AB.
    Nytt Ramprogram på CBI - Beständighet och hydratation2013In: CBI-nytt, ISSN 0349-2060, no 2, p. 3-4, 13Article in journal (Other academic)
  • 42.
    Mueller, Urs
    et al.
    RISE, SP – Sveriges Tekniska Forskningsinstitut, CBI Betonginstitutet AB.
    von Weschpfennig, Dieter
    Anti-Graffiti-Systeme auf Mauerwerk im Bereich der Bundesfernstraßen2011In: Bautechnik, ISSN 0932-8351, Vol. 88, no 7, p. 443–450-Article in journal (Other academic)
  • 43.
    Mueller, Urs
    et al.
    RISE - Research Institutes of Sweden, Built Environment, CBI Swedish Cement and Concrete Research Institute.
    Williams Portal, Natalie
    RISE - Research Institutes of Sweden, Safety and Transport, Safety.
    Flansbjer, Mathias
    RISE - Research Institutes of Sweden, Safety and Transport, Safety.
    Malaga, Katarina
    RISE - Research Institutes of Sweden, Built Environment, CBI Swedish Cement and Concrete Research Institute.
    Textile Reinforced Reactive Powder Concrete and its Application for Facades2017Conference paper (Refereed)
    Abstract [en]

    Reactive powder concrete (RPC) is a fairly novel material with extraordinary strength and durability properties. Due to these properties, it is increasingly being utilized also for external facade cladding thus enabling a considerable reduction in the thickness of concrete elements. Commercial RPC formulations on the market have drawbacks in terms of sustainability due to their high clinker content and heat curing which is often applied to increase final strength and material density. The presented study focusses on improved formulations with higher replacement levels of cement clinker by supplementary cementitious materials (SCMs). One different mix formulation was designed and tested in terms of mechanical properties. The formulation was combined with carbon textile reinforcements primarily to enhance the flexural and tensile behavior of the material. The results showed that even with clinker replacement levels of up to 33 % of the total binder amount, a satisfactory mechanical performance of the RPC mix could still be achieved. Fairly steep strength gains rendered heat treatment unnecessary. The incorporation of carbon textile fiber grids proved to be effective in improving the post peak performance of the RPC. However, their performance depended strongly on the bond between the carbon grid and the RPC. Higher moister contents in the concrete proved to reduce the bond strength between the carbon textile and the cement paste. This is maybe less relevant for facades but structural elements with textile reinforcement and RPC might perform less well in completely submerged environment.

  • 44.
    Mueller, Urs
    et al.
    RISE, SP – Sveriges Tekniska Forskningsinstitut, CBI Betonginstitutet AB.
    Ziegert, C
    Eigenschaften industrieller lehmbauprodukte für den mauerwerksbau und verhalten von lehmsteinmauerwerk2012In: Masonry, ISSN 1432-3427, E-ISSN 1437-1022, Vol. 16, no 1, p. 17-28Article in journal (Other academic)
    Abstract [de]

    Properties of industrially produced earthen building products for masonry and behaviour of earth block masonry. The contribution gives an overview of the properties of industrially produced earthen building products for masonry. In the meantime the quality of the industrial production of this group of building materials reached a level similar to that of other products for construction. Earth plasters exist as plasters for universal, one or multi layer applications or as lower, upper or finish plasters. Earth blocks are provided in different sizes and with different perforations. The mechanical properties of different earth block types are signified by compressive strength of up to 11 N/mm2 but are typically in a range between 2 and 5 N/mm2. A critical point is the correlation of the strength of earthen materials with their moisture content. Results from earth blocks showed that in a relative humidity window between 40 and 70 % rh the compressive strength of earth blocks is fairly constant. Masonry made from earth block and earth mortar exhibited compressive strength and elastic modules similar to masonry made with aerated autoclaved concrete blocks. The shear strength of earth block masonry, however, is fairly low, due to the weak bond between earth block and earth mortar.

  • 45. Schlegel, M C
    et al.
    Mueller, Urs
    RISE, SP – Sveriges Tekniska Forskningsinstitut, CBI Betonginstitutet AB.
    Spatially resolved investigation of complex multi-phase systems using μxRF, SEM-EDX and high resolution SyXRD2013In: Cement & Concrete Composites, ISSN 0958-9465, E-ISSN 1873-393X, Vol. 37, no 1, p. 241-245Article in journal (Refereed)
    Abstract [en]

    Spatially resolved analysis of complex multi-phase systems can be validated through different analytical methods. This study compares investigations by scanning electron microscopy coupled with energy dispersive X-ray fluorescence analysis and high resolution X-ray diffraction. The studied sulfate attacked cement paste containing fly ashes consists of different interacting crystalline and amorphous phases. The complementary methods revealed in detail changes in phase composition due to the chemical attack. The advantages and disadvantages of both methods are discussed and suggestions are given for combining them with additional methods to maximize the information content.

  • 46.
    Silva, Nelson
    et al.
    RISE, SP – Sveriges Tekniska Forskningsinstitut, CBI Betonginstitutet AB, Betong & Berg.
    Mueller, Urs
    RISE, SP – Sveriges Tekniska Forskningsinstitut, CBI Betonginstitutet AB, Betong & Berg.
    Malaga, Katarina
    RISE, SP – Sveriges Tekniska Forskningsinstitut, CBI Betonginstitutet AB.
    Hallingberg, Per
    Cederqvist, Christer
    Foam concrete-aerogel composite for thermal insulation in lightweight sandwich2015In: Concrete 2015: the 27th Biennial National Conference of the Concrete Institute of Australia in conjunction with the 69th RILEM Week, “Construction Innovations, Research into Practice”, Institute of Australia , 2015, p. 1355-1362Conference paper (Refereed)
    Abstract [en]

    This paper describes the initial steps towards the development of a foam concrete-aerogelcomposite for thermal insulation in lightweight sandwich façade elements. Fire safety is an important issuepertaining insulation materials. Therefore, the need for low-density inorganic, non-flammable materials israpidly increasing. Foam concrete is a lightweight material with good thermal characteristics; densities aslow as 400 kg/m3 and thermal conductivities as low as 100 mW/m·K can easily be achieved. The mainadvantage when compared to typical inorganic insulations (e.g. autoclaved aerated concrete or mineralwool) is that foam concrete has a much lower embodied energy, in particular due to the simplicity of themanufacturing process. However, in order to be competitive as an effective insulation material, thethermal conductivity needs to be drastically reduced which can be achieved by reducing the density andby incorporating silica aerogels (both measures affecting the compressive strength).

  • 47. Vera-Agullo, J
    et al.
    Lample, R
    Nelson, Silva
    RISE, SP – Sveriges Tekniska Forskningsinstitut, CBI Betonginstitutet AB, Betong & Berg.
    Mueller, Urs
    RISE, SP – Sveriges Tekniska Forskningsinstitut, CBI Betonginstitutet AB, Betong & Berg.
    Malaga, Katarina
    RISE, SP – Sveriges Tekniska Forskningsinstitut, CBI Betonginstitutet AB.
    Durability of concrete exposed to sea water at early age: Flotaing dock method for construction of caissons2016In: Proceedings of the Second International Conference on Concrete Sustainability, International Center for Numerical Methods in Engineering (CIMNE) , 2016, p. 250-260Conference paper (Refereed)
    Abstract [en]

    ACCIONA Infrastructure, a Spanish contractor, uses the caisson method for the construction of breakwater structures. One of its floating docks, Kugira, is one of the largest of its kind in the world and it can produce concrete caissons measuring 70 m long by 36 m wide and 35 m high. Concrete caissons made in floating docks are gradually immersed in sea water as they are built; thus, the set concrete is exposed to sea water at a very early stage, within 18 to 48 hours after casting in sliding formwork. In order to study the durability of slag concrete using this construction method, the properties of concrete exposed to sea water at a very young age have been tested. Specimens were exposed to artificial sea water by the ponding method at different ages (16h, 1, 2, 3, 7 and 28 days) for a period of 6, 18 and 36 (analysis pending) months. The following properties were measured and compared with unexposed specimens: compressive strength, water and oxygen permeability, pore size distribution, migration coefficient DNT492 and chloride profiles. After 6 and 18 months ponding, lower chloride contents were measured for the specimens exposed to sea water after 28 days curing compared to those exposed at early ages. However, this difference significantly decreases within a small depth from the exposed surface. Also the migration coefficient DNT492 decreases significantly with the increase of the age of the concrete. With regards to water and oxygen permeability, no significant differences were found. In this paper, a summary of all these works is presented.                

  • 48. Vera-Agullo, Jose
    et al.
    Castro-Visos, Francisco Manuel
    Larraz-Bordanaba, Francisco Javier
    Troncone-Cusati, Claudio
    Asencio-Varela, Juan Pedro
    Silva, Nelson
    RISE, SP – Sveriges Tekniska Forskningsinstitut, CBI Betonginstitutet AB, Betong & Berg.
    Mueller, Urs
    RISE, SP – Sveriges Tekniska Forskningsinstitut, CBI Betonginstitutet AB, Betong & Berg.
    Malaga, Katarina
    RISE, SP – Sveriges Tekniska Forskningsinstitut, CBI Betonginstitutet AB.
    Durability of concrete caissons made in floating docks2015In: Concrete 2015: the 27th Biennial National Conference of the Concrete Institute of Australia in conjunction with the 69th RILEM Week, “Construction Innovations, Research into Practice”, Institute of Australia , 2015, p. 894-903Conference paper (Refereed)
    Abstract [en]

    ACCIONA Infrastructure, a Spanish contractor, uses the caisson method for the construction ofbreakwater structures. One of its floating docks, Kugira, is one of the largest of its kind in the world and itcan produce concrete caissons measuring 70 m long by 36 m wide and 35 m high. Concrete caissonsmade in floating docks are gradually immersed in sea water as they are built; thus, the set concrete isexposed to sea water at a very early stage, within 18 to 48 hours after casting in sliding formwork. In orderto study the durability of slag concrete using this construction method, the properties of concrete exposedto sea water at a very young age have been tested. Specimens were exposed to artificial sea water by theponding method at different ages (16h, 1, 2, 3, 7 and 28 days) for a period of 6, 18 and 36 (analysispending) months. The following properties were measured and compared with unexposed specimens:compressive strength, water and oxygen permeability, pore size distribution, migration coefficient DNT492and chloride profiles. After 6 and 18 months ponding, lower chloride contents were measured for thespecimens exposed to sea water after 28 days curing compared to those exposed at early ages.However, this difference significantly decreases within a small depth from the exposed surface. Also themigration coefficient DNT492 decreases significantly with the increase of the age of the concrete. Withregards to water and oxygen permeability, no significant differences were found. In this paper, a summaryof all these works is presented.Apart from this laboratory analysis, real scale tests were performed at site with the aim to increasedurability by the addition of nanosilica particles. The characterization of these real scale tests are alsodescribed and discussed in this paper.

  • 49.
    Williams Portal, Natalie
    et al.
    RISE - Research Institutes of Sweden, Safety and Transport, Safety.
    Flansbjer, Mathias
    RISE - Research Institutes of Sweden, Safety and Transport, Safety.
    Malaga, Katarina
    RISE - Research Institutes of Sweden, Built Environment, CBI Swedish Cement and Concrete Research Institute.
    Mueller, Urs
    RISE - Research Institutes of Sweden, Built Environment, CBI Swedish Cement and Concrete Research Institute.
    Anchorage of Textile Reinforcement in High-Performance Concrete2017Conference paper (Refereed)
    Abstract [en]

    The mechanical properties of textile reinforced high-performance concrete (TRHPC) applied in innovative lightweight sandwich elements has been investigated in the framework of EC supported FP7 project, H-House (Healthier Life with Eco-innovative Components for Housing Constructions). TRHPC offers new possibilities for architects and engineers to create thinner and more durable concrete façade elements. Textile reinforcement grids are typically woven from non-metallic rovings usually consisting of continuous glass, rock or carbon fibres. The most promising performing textile reinforcement alternative in terms of mechanical and durability performance consists of carbon fibres. Carbon fibres do however have an inherent smooth surface which is unfavourable concerning its bond to the cement paste, which is often improved by polymer-based coatings. The bond behaviour, being a critical design parameter, should be investigated for TRHPC in order to understand limitations regarding required anchorage lengths for use in applications such as façade elements. The aim of this study was to quantify and verify the required anchorage length for a selected epoxy impregnated carbon textile reinforced TRHPC combination. To achieve this aim, the bond behaviour, leading to a suitable anchorage length (or overlap), was firstly studied by means of pull-out tests. Thereafter, the ultimate strength of the composite material was measured via uniaxial tensile testing with and without an overlap splice according to the findings from the pull-out tests. Optical measurements during the pull-out tests were performed using a video extensometer technique and by Digital Image Correlation (DIC) for the uniaxial tensile tests. Results indicated that the required anchorage length to yield rupture of the textile reinforcement in pull-out was deemed appropriate as an overlapping length when tested in tension. The combination of these two experimental methods on the composite level was useful for determining the overlapping length required for the TRHPC which could be applied in larger scale applications.

  • 50.
    Williams Portal, Natalie
    et al.
    RISE - Research Institutes of Sweden, Safety and Transport, Safety.
    Flansbjer, MathiasRISE - Research Institutes of Sweden, Safety and Transport, Safety.Mueller, UrsRISE - Research Institutes of Sweden, Built Environment, CBI Swedish Cement and Concrete Research Institute.
    Analysis of the Flexural Behavior of Textile Reinforced Reactive Powder Concrete Sandwich Elements Using Optical Measurements2018Conference proceedings (editor) (Refereed)
    Abstract [en]

    Prefabricated and non-load bearing sandwich façade elements were developed using Textile Reinforced Reactive Powder Concrete (TRRPC) along with low density Foamed Concrete (FC) and Glass Fiber Reinforced Polymer (GFRP) continuous connecting devices. Four-point bending tests were performed on large-scale TRRPC sandwich element beams to characterize the structural performance, which included the flexural capacity, level of composite action, resulting deformation, crack propagation and failure mechanisms. Optical measurements based on Digital Image Correlation (DIC) were taken simultaneously to enable a detailed analysis of the underlying composite action. The structural behavior of the developed elements was found to be highly dependent on the stiffness and strength of the connectors to ensure composite action between the two TRRPC panels.

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