Change search
Link to record
Permanent link

Direct link
BETA
Alternative names
Publications (10 of 53) Show all publications
Hesselgren, L., Andreasson, I., Mueller, U., Prieto Rábade, M. & Janhäll, S. (2019). NuMo – New Urban Mobility: New urban infrastructure support for autonomous vehicles.
Open this publication in new window or tab >>NuMo – New Urban Mobility: New urban infrastructure support for autonomous vehicles
Show others...
2019 (English)Report (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.

National Category
Natural Sciences
Identifiers
urn:nbn:se:ri:diva-37736 (URN)
Note

Project: Urban Infrastructure Opportunities with Autonomous Vehicles. Project Number: 2018-00628. InfraSweden 2030 Strategic Innovation Program.  A joint program by Vinnova, FORMAS and Energimyndigheten

 

Available from: 2019-02-07 Created: 2019-02-07 Last updated: 2019-02-07
Miccoli, L., Silva, R., Oliveira, D. & Mueller, U. (2019). Static behavior of cob: Experimental testing and finite-element modeling. Journal of materials in civil engineering, 31(4), Article ID 04019021.
Open this publication in new window or tab >>Static behavior of cob: Experimental testing and finite-element modeling
2019 (English)In: Journal of materials in civil engineering, ISSN 0899-1561, E-ISSN 1943-5533, Vol. 31, no 4, article id 04019021Article in journal (Refereed) Published
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.

Keywords
Cob, Compression behavior, Digital image correlation, Finite-element method, Shear behavior, Compression testing, Numerical models, Sensitivity analysis, Shear strain, Shear stress, Uncertainty analysis, Diagonal compression tests, Digital image correlations, Experimental testing, Mechanical parameters, Rotating crack model, Stress-strain relationships, Finite element method
National Category
Natural Sciences
Identifiers
urn:nbn:se:ri:diva-37750 (URN)10.1061/(ASCE)MT.1943-5533.0002638 (DOI)2-s2.0-85061005839 (Scopus ID)
Note

Funding details: Federación Española de Enfermedades Raras, FEDER, POCI-01-0145-FEDER-007633; Funding text 1: The authors wish to express their gratitude to Mr. André Gardei for his important support in the experimental program and to Mr. Andreas Barner and Ms. Manuela Peuschel for their support with photogrammetric analyses. This study was funded by the European Commission within the framework of the project NIKER (Grant No. 244123) dealing with improving immovable Cultural Heritage assets against the risk of earthquakes. The study was partly financed by FEDER funds through the Competitivity Factors Operational Programme (project POCI-01-0145-FEDER-007633) and by national funds through the Portuguese Foundation for Science and Technology (project PTDC/ECM-EST/2777/2014 and Grant No. SFRH/BPD/97082/2013).

Available from: 2019-02-11 Created: 2019-02-11 Last updated: 2019-03-07Bibliographically approved
Williams Portal, N., Flansbjer, M. & Mueller, U. (Eds.). (2018). Analysis of the Flexural Behavior of Textile Reinforced Reactive Powder Concrete Sandwich Elements Using Optical Measurements. Paper presented at 18th International Conference on Experimental Mechanics, Brussels, Belgium, 1–5 July 2018.. MDPI
Open this publication in new window or tab >>Analysis of the Flexural Behavior of Textile Reinforced Reactive Powder Concrete Sandwich Elements Using Optical Measurements
2018 (English)Conference 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.

Place, publisher, year, edition, pages
MDPI, 2018
Keywords
Reactive Powder Concrete; Textile Reinforced Concrete; Foam Concrete; Glass Fiber
National Category
Building Technologies
Identifiers
urn:nbn:se:ri:diva-33930 (URN)10.3390/ICEM18-05221 (DOI)
Conference
18th International Conference on Experimental Mechanics, Brussels, Belgium, 1–5 July 2018.
Funder
EU, FP7, Seventh Framework Programme, 608950
Available from: 2018-06-11 Created: 2018-06-11 Last updated: 2018-08-16Bibliographically approved
Flansbjer, M., Williams Portal, N., Vennetti, D. & Mueller, U. (2018). Composite Behaviour of Textile Reinforced Reactive Powder Concrete Sandwich Façade Elements. International Journal of Concrete Structures and Materials, 12(1), Article ID 71.
Open this publication in new window or tab >>Composite Behaviour of Textile Reinforced Reactive Powder Concrete Sandwich Façade Elements
2018 (English)In: International Journal of Concrete Structures and Materials, ISSN 1976-0485, E-ISSN 2234-1315, Vol. 12, no 1, article id 71Article in journal (Refereed) Published
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).

Keywords
finite element analysis (FEA), foam concrete (FC), four-point bending test, reactive powder concrete (RPC), sandwich elements, textile reinforced concrete (TRC), Bending tests, Cracks, Fiber reinforced plastics, Finite element method, Intelligent buildings, Optical correlation, Reinforced concrete, Sandwich structures, Stiffness, Structural analysis, Textiles, Foam concretes, Reactive powder concrete, Sandwich element, Textile reinforced concretes, Failure (mechanical)
National Category
Natural Sciences
Identifiers
urn:nbn:se:ri:diva-36594 (URN)10.1186/s40069-018-0301-4 (DOI)2-s2.0-85057099836 (Scopus ID)
Available from: 2018-12-06 Created: 2018-12-06 Last updated: 2018-12-06Bibliographically approved
Lundgren, M., Babaahmadi, A. & Mueller, U. (2018). Exposure experiments in sulfate containing solution, including exposure at low temperature.
Open this publication in new window or tab >>Exposure experiments in sulfate containing solution, including exposure at low temperature
2018 (English)Report (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.

Publisher
p. 30
Series
RISE Rapport ; 2018:09
Keywords
Cement, Supplementary Cementitious Materials (SCM), Testing, Sulfate ingress
National Category
Materials Chemistry Civil Engineering
Identifiers
urn:nbn:se:ri:diva-34868 (URN)978-91-88695-44-4 (ISBN)
Available from: 2018-08-21 Created: 2018-08-21 Last updated: 2018-11-14Bibliographically approved
Boubitsas, D., Tang, L., Fridh, K., Mueller, U. & Utgenannt, P. (2018). Frost Resistance of Concrete – Experience from Long-Term Field Exposure.
Open this publication in new window or tab >>Frost Resistance of Concrete – Experience from Long-Term Field Exposure
Show others...
2018 (English)Report (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.

Publisher
p. 153
Series
RISE Rapport ; 2018:65
Keywords
Concrete, field exposure, salt-frost resistance, chloride ingress, corrosion, durability
National Category
Natural Sciences
Identifiers
urn:nbn:se:ri:diva-37574 (URN)978-91-88907-09-7 (ISBN)
Available from: 2019-01-24 Created: 2019-01-24 Last updated: 2019-01-24
Lundgren, M., Helsing, E., Babaahmadi, A. & Mueller, U. (2018). State-of-the-Art Report on: Material Type, Requirements and Durability aspects of Sprayed Concrete in Tunnels.
Open this publication in new window or tab >>State-of-the-Art Report on: Material Type, Requirements and Durability aspects of Sprayed Concrete in Tunnels
2018 (English)Report (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.

Publisher
p. 64
Series
RISE Rapport ; 2018:08
Keywords
sprayed concrete, underground constructions, mix design, applications in Sweden and other countries, requirements in standards, guidelines, durability
National Category
Civil Engineering Infrastructure Engineering
Identifiers
urn:nbn:se:ri:diva-34865 (URN)978-91-88695-43-7 (ISBN)
Available from: 2018-08-21 Created: 2018-08-21 Last updated: 2018-11-14Bibliographically approved
Williams Portal, N., Flansbjer, M., Malaga, K. & Mueller, U. (2017). Anchorage of Textile Reinforcement in High-Performance Concrete. In: : . Paper presented at Eleventh High Performance concrete (11th HPC) and the Second Concrete Innovation Conference (2nd CIC,)Tromsø 6-8 March 2017. , Article ID No. 36.
Open this publication in new window or tab >>Anchorage of Textile Reinforcement in High-Performance Concrete
2017 (English)Conference paper, Published 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.

Keywords
Textile reinforced concrete, high-performance concrete, pull-out testing, bond, uniaxial tensile testing
National Category
Building Technologies
Identifiers
urn:nbn:se:ri:diva-29214 (URN)
Conference
Eleventh High Performance concrete (11th HPC) and the Second Concrete Innovation Conference (2nd CIC,)Tromsø 6-8 March 2017
Projects
H-House
Funder
EU, FP7, Seventh Framework Programme, 608893
Available from: 2017-04-05 Created: 2017-04-05 Last updated: 2018-08-16Bibliographically approved
Appelquist, K., Mueller, U. & Trägårdh, J. (2017). Detection of potential alkali-silica reactivity of aggregates from Sweden. In: : . Paper presented at 16th Euroseminar on Microscopy Applied to Building Materials EMABM, Book of abstracts, Les Diablerets, Switzerland, May 14-17, 2017.
Open this publication in new window or tab >>Detection of potential alkali-silica reactivity of aggregates from Sweden
2017 (English)Conference paper, Oral presentation with published abstract (Other academic)
National Category
Materials Chemistry
Identifiers
urn:nbn:se:ri:diva-33273 (URN)
Conference
16th Euroseminar on Microscopy Applied to Building Materials EMABM, Book of abstracts, Les Diablerets, Switzerland, May 14-17, 2017
Note

Extended abstract (3-4 pp.)

Available from: 2018-02-09 Created: 2018-02-09 Last updated: 2018-08-15Bibliographically approved
Williams Portal, N., Flansbjer, M. & Mueller, U. (2017). Experimental Study on Anchorage in Textile Reinforced Reactive Powder Concrete. Nordic Concrete Research, 57(2), 73-88, Article ID 6.
Open this publication in new window or tab >>Experimental Study on Anchorage in Textile Reinforced Reactive Powder Concrete
2017 (English)In: Nordic Concrete Research, ISSN 0800-6377, Vol. 57, no 2, p. 73-88, article id 6Article in journal (Refereed) Published
Abstract [en]

The EC funded project SESBE (Smart Elements for Sustainable Building Envelopes) focused on utilizing new types of cementitious materials for reducing the mass and thickness of façade elements while increasing their thermal performance. A method enabling the quantification and verification of the required anchorage length for a given textile reinforced reactive powder concrete (TRRPC) is presented. At the material level, tensile tests were conducted to determine the tensile properties of the reinforcement. Pull-out tests were applied to quantify the required anchorage length, while uniaxial tensile tests were performed to quantify the ultimate strength and verify the suitability of the anchorage length at the composite level. The combination of these methods was deemed useful to determine the overlapping length required for larger scale façade applications.

Keywords
reactive powder concrete, textile reinforcement, anchorage, testing
National Category
Building Technologies
Identifiers
urn:nbn:se:ri:diva-32827 (URN)
Projects
SESBE(Smart Elements for Sustainable Building Envelopes)
Available from: 2017-12-06 Created: 2017-12-06 Last updated: 2018-08-16Bibliographically approved
Identifiers
ORCID iD: ORCID iD iconorcid.org/0000-0003-1904-7426

Search in DiVA

Show all publications
v. 2.35.5