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Al-Ayish, N., During, O., Malaga, K., Silva, N. & Gudmundsson, K. (2018). The influence of supplementary cementitious materials on climate impact of concrete bridges exposed to chlorides. Construction and Building Materials, 188, 391-398
Open this publication in new window or tab >>The influence of supplementary cementitious materials on climate impact of concrete bridges exposed to chlorides
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2018 (English)In: Construction and Building Materials, ISSN 0950-0618, E-ISSN 1879-0526, Vol. 188, p. 391-398Article in journal (Refereed) Published
Abstract [en]

In order to reach a specific service life of reinforced concrete structures a certain cover thickness is needed. At present, this is regulated by national standards that also limit the amount and type of supplementary cementitious materials in different exposure environments. The regulations do not, however, consider the actual durability performance of concrete with supplementary cementitious materials. As a consequence, the LCA results might be misleading. This paper shows the environmental impact of concrete with supplementary cementitious materials in chloride environment considering their specific performances. Prescriptive and performance based service life prediction models for chloride ingress are applied and compared.

Keywords
Bridge, Chloride ingress, Climate impact, Corrosion, Durability, LCA, Service life, Supplementary cementitious materials (SCM), Sustainability, Bridges, Chlorine compounds, Reinforced concrete, Sustainable development, Chloride environment, Climate impacts, Durability performance, Exposure environment, Performance based, Service life prediction, Supplementary cementitious material, Environmental impact
National Category
Natural Sciences
Identifiers
urn:nbn:se:ri:diva-35585 (URN)10.1016/j.conbuildmat.2018.08.132 (DOI)2-s2.0-85052208549 (Scopus ID)
Available from: 2018-11-06 Created: 2018-11-06 Last updated: 2018-11-06Bibliographically approved
Helsing, E., Malaga, K., Silva, N., Eva, R., Torkkeli, M. & Hejll, A. (2017). A Nordic method for testing hydrophobic impregnations with regard to prevention of chloride ingress.
Open this publication in new window or tab >>A Nordic method for testing hydrophobic impregnations with regard to prevention of chloride ingress
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2017 (English)Report (Other academic)
Abstract [en]

Chloride induced corrosion of the reinforcement is the major cause of degradation of reinforced concrete structures. In particular in the Nordic countries, the use of de-icing salts during winter, leads to severe degradation of edge beams in road bridges. Thus, in order to extend the service life and decrease maintenance costs, hydrophobic impregnations are commonly used to prevent or slow down chloride ingress into concrete. There is a harmonised European standard for hydrophobic impregnations, EN 1504-2 [1], but the property “diffusion of chloride ions” is “subject to national standards and regulations”. The transport and road administrations of Sweden, Norway and Finland use different national methods to evaluate the performance of this type of products meaning that the same CEmarked product needs to meet different requirements. Therefore, the transport and road administrations of Sweden, Norway and Finland initiated a project with the aim to establish a common Nordic method for classification of hydrophobic impregnations with regard to their capability to protect concrete from chloride ingress. The project was divided into three phases consisting on the analysis of existing test standards (national and international), a pre-study to evaluate the influence of different tests parameters and a round robin test involving three laboratories (one in each country). A thorough comparison of the existing methods and review of relevant literature made it possible to define which test parameters could be used in the formulation of the new method and which ones required further studies. It was found that the type of surface to be treated, the length of the preconditioning period, the length of the curing period and whether the surface to be impregnated should be soaked with Ca(OH)2-solution or not should be further investigated. The results of the pre-study showed that the application of the impregnation to form surfaces led to somewhat better chloride blocking effect. Despite this, it was decided to use sawn surfaces in the method, since it is much easier to obtain reproducible surface characteristics that way. The characteristics of a form surface depend on e.g. the form material, use of release agents, curing conditions. Saturation of the surface with calcium hydroxide solution before impregnation was found slightly beneficial on the chloride blocking effect compared to when such a treatment was omitted. However, since this did not contribute to the robustness of the test results, it increased the number of experimental steps and it is not representative of practice in real structures, it was decided not to incorporate such a treatment in the new method. The chloride protection slightly increases with the impregnation curing time. It was not clear which factor was most dominant; if the continuous polymerization of the hydrophobic impregnation or the continuous cement hydration. Since enough curing time is necessary for the treatment to be efficient, it was decided that the curing period before exposure to chlorides should be 28 days. With the primary objective of determining the reliability and reproducibility of the new method, a round robin exercise was carried out. Three laboratories were involved in this phase; CBI-Borås in Sweden, SINTEF in Norway and VTT in Finland. The results show that despite some differences in both materials and methods, such as the type of cement or preconditioning and curing environments, highly reproducible results were obtained. In addition, a detailed discussion on the influence of the details of the method on the chloride profiles and on the filter effect is presented. Within the round robin test, the relative humidity before and after impregnation and the dry condition of the powder samples were found to be the major parameters leading to the discrepancy of the results. In addition, handling of the wet concrete surfaces after exposure to chlorides and the time period (and temperature) between the end of the chloride exposure and powder sampling for chloride analysis were found to have surprisingly large effects on the form of the chloride profiles in the samples. Therefore, these parts of the procedures were made much more precise in the final method, in order to increase its reproducibility. The method can be briefly described as follows: Concrete specimens are prepared by sawing 100 mm cubes into two halves, three cubes per test series. The sawn surfaces are defined as exposure faces. Three halves are treated with the hydrophobic impregnation to be tested and the other three halves are kept as untreated references. The specimens are exposed submerged in 15% NaCl-solution for 56 days. After exposure, the chloride ingress is determined by profile grinding and the total amount of penetrated chlorides is calculated. The chloride blocking effect of the hydrophobic impregnations, expressed as the Filter Effect, FE, which is determined as 1 minus the ratio between the amount of penetrated chlorides in treated and in non-treated concrete specimens. The results obtained in both the pre-study and round robin exercise were compared to those obtained with the existing national methods in order to establish proper requirement levels with the new method. Despite the many differences between the methods, it was found that a filter effect of approximately 0.65 correlates well with the existing requirement in the Swedish method and in the Norwegian method. However, given limited data available and also considering data from field investigations, a level of 0.60 is proposed as appropriate for a really well performing hydrophobic impregnation. The method was accepted as a Nordtest method in December 2015 with the denomination NT Build 515.

Abstract [sv]

Kloridinducerad korrosion av armering är den främsta orsaken till skador på armerade betongkonstruktioner. I de nordiska länderna i synnerhet, leder användning av avisningssalter under vintersäsongen till allvarliga skador på kantbalkar på vägbroar. För att förlänga livslängden och minska underhållskostander används därför vanligtvis vattenavvisande impregnering för att förhindra eller sakta ner kloridinträngningen i betongen. Det finns en harmoniserad europastandard för vattenavvisande impregnering, EN 1504-2 [1], men egenskapen ”diffusion av kloridjoner” är enligt den ”underställd nationella standarder eller regler”. Transport och vägmyndigheterna i Sverige, Norge och Finland använder olika nationella metoder för att bedöma sådana produkters prestanda med avseende på skydd mot kloridinträngning, vilket innebär att samma CE-märkta produkt måste uppfylla olika nationella kriterier. Därför initierade transport- och vägmyndigheterna i Sverige, Norge och Finland ett projekt med målet att ta fram en gemensam nordisk metod för att klassificera vattenavvisande impregnering med hänsyn till deras förmåga att skydda betong från kloridinträngning.Projektet uppdelades i tre faser som bestod av en analys av existerande provningsstandarder (nationella och internationella), en förstudie för att utvärdera inverkan av några provningsparametrar samt en ”round robin”-provning (RR-provning) som involverade tre laboratorier (ett från vardera land). En noggrann genomgång av de existerande metoderna och av relevant litteratur möjliggjorde att provningsparametrar som direkt kunde användas i den nya metoden och vilka parametrar som krävde ytterligare studier. Det bestämdes att typ av yta som skulle behandlas, längden på förkonditioneringen och om ytan skulle exponeras för en Ca(OH)2-lösning eller inte skulle studeras mer ingående i förstudien. Resultaten från förstudien visade att man fick en något bättre kloridblockerande förmåga om impregneringen anbringades på en formyta än på en sågad yta. Trots detta valdes sågade ytor för metoden, eftersom det är mycket enklare att uppnå reproducerbara egenskaper hos yta på det sättet. En formytas egenskaper beror bl.a. på formmaterial, formsläppmedel, härdningsbetingelser.Mättning av ytan med kalklösning innan impregneringen utfördes gav något bättre kloridblockerande förmåga än om denna behandling inte utfördes. Eftersom detta inte bidrog till resultatens robusthet, ökade antal procedurer i provningen och inte görs i praktiken i fält, bestämdes det att detta inte skulle tas med i den nya metoden. Den kloridblockerande förmågan ökar något med den tid impregneringen får härda. Det är inte klarlagt vilken som var den dominerande faktorn, fortsatt polymerisering av den vattenavvisande impregneringen eller cementets fortsatta hydratisering. Eftersom det krävs tillräcklig tid för att impregneringen ska härda för att behandlingen ska få full effekt, bestämdes att härdningstiden innan provkropparna utsattes för klorider skulle vara 28 dygn.För att främst klarlägga tillförlitligheten och reproducerbarheten hos den nya metoden, genomfördes en RR-provning. Tre laboratorier ingick i denna fas; CBI-Borås i Sverige, SINTEF i Norge och VTT i Finland. Resultaten visade att trots vissa skillnader i både material och metod, som typ av cement och förkonditionerings- och konditioneringsmiljö, så erhölls resultat med hög reproducerbarhet. I rapporten ges dessutom en detaljerad genomgång av inverkan av olika detaljer i metoden på kloridprofiler och den kloridblockerande förmågan, bestämd som en filterseffekt.I RR-provningen visade det sig att den relativa fuktigheten före och efter impregnering och graden av torrt hos de malda proverna var de främsta källorna för avvikelser i provningsresultat. Dessutom visade sig hanteringen av de våta ytorna efter exponering för kloridlösning och tidsperioden (och temperatur) mellan kloridexponeringens avslut och uttagning av pulverprover för kloridanalys hade en förvånansvärt stor inverkan på kloriprofilernas form i provkropparna. Därför preciserades dessa delar ytterligare i den slutliga metoden för att öka metodens reproducerbarhet.Metoden beskrivs i korthet i det följande:Betongprover tillverkas genom att såga 100 mm kuber i två halvor, totalt 6 halvor. Den sågade ytan användes som exponeringsyta. Efter en viss förkonditionering behandlas tre kuber med den vattenavvisande impregneringen och tre lämnas obehandlade (referenser). Efter 28 dygns härdning av impregneringen exponeras proverna för klorider genom nedsänkning i 15% NaCl-lösning under 56 dygn. Efter exponering bestäms kloridinträngningen genom att kloridprofilen bestäms och total mängd klorid beräknas. Den kloridblockerande effekten hos den vattenavvisande impregneringen, uttryckt som filtereffekten FE, som bestäms som 1 minus kvoten mellan mängd inträngd klorid i de impregnerade proverna och i referensproverna.Resultaten från förstudien och RR-provningen jämfördes med resultat som erhållits med de existerande nationella metoderna för att kunna fastställa en lämplig kravnivå för den nya metoden. Trots stora skillnader i de existerande metoderna visade det sig att en filtereffekt på ca 0,65 korrelerar väl med kraven relaterade till både den svenska och den norska metoden. Eftersom mängden jämförbara data är liten och om man även beaktar resultat från fältundersökningar, förslås en mingräns på FE=0,60 som ett lämpligt krav för att en vattenavvisande impregnering ska anses vara väl fungerande.Metoden antogs som en Nordtestmetod med beteckningen NT Build 515 i december 2015.

Publisher
p. 115
Series
CBI rapport, ISSN 0346-8240 ; 2017:3
Keywords
concrete, chloride ingress, hydrophobic impregnation, performance test, test method, chloride diffusion
National Category
Other Materials Engineering Infrastructure Engineering
Identifiers
urn:nbn:se:ri:diva-33619 (URN)978-91-980851-3-6 (ISBN)
Available from: 2018-04-11 Created: 2018-04-11 Last updated: 2018-12-20Bibliographically 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
Williams Portal, N., Flansbjer, M., Zandi, K., Wlasak, L. & Malaga, K. (2017). Bending behaviour of novel Textile Reinforced Concrete-foamed concrete (TRC-FC) sandwich elements. Composite structures, 177, 104-118
Open this publication in new window or tab >>Bending behaviour of novel Textile Reinforced Concrete-foamed concrete (TRC-FC) sandwich elements
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2017 (English)In: Composite structures, ISSN 0263-8223, E-ISSN 1879-1085, Vol. 177, p. 104-118Article in journal (Refereed) Published
Abstract [en]

A novel sandwich element design consisting of two facings made of carbon reinforced Textile Reinforced Concrete (TRC), a low density foamed concrete (FC) core and glass fibre reinforced polymer (GFRP) connecting devices was experimentally investigated according to quasi-static and cyclic quasi-static fourpoint bending. Optical measurements based on Digital Image Correlation (DIC) were taken during testing to enable a detailed analysis of the bending behaviour and level of composite action. A model, verified by the experiments, was developed based on non-linear finite element analysis (NLFEA) to gain further insight on the failure mechanisms. Under both loading conditions, the bending behaviour of the TRCFC composite elements was characterized by favourable load bearing capacity, partial composite action, superior ductility and multiple fine cracking. The connecting devices were found to be the critical elements causing the initial failure mechanism in the form of localized pull-out within an element.

National Category
Building Technologies
Identifiers
urn:nbn:se:ri:diva-30029 (URN)10.1016/j.compstruct.2017.06.051 (DOI)2-s2.0-85021406539 (Scopus ID)
Projects
H-House
Funder
EU, European Research Council, 608893
Available from: 2017-06-30 Created: 2017-06-30 Last updated: 2019-01-07Bibliographically approved
Mueller, U., Williams Portal, N., Flansbjer, M. & Malaga, K. (2017). Textile Reinforced Reactive Powder Concrete and its Application for Facades. 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.53.
Open this publication in new window or tab >>Textile Reinforced Reactive Powder Concrete and its Application for Facades
2017 (English)Conference paper, Published 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.

Keywords
Reactive powder concrete, textile reinforcement, flexural behavior, mineral additions
National Category
Building Technologies
Identifiers
urn:nbn:se:ri:diva-29216 (URN)
Conference
Eleventh High Performance concrete (11th HPC) and the Second Concrete Innovation Conference (2nd CIC), Tromsø, 6-8 March 2017
Projects
SESBE
Funder
EU, FP7, Seventh Framework Programme, 608950
Available from: 2017-04-05 Created: 2017-04-05 Last updated: 2018-08-16Bibliographically approved
Vera-Agullo, J., Lample, R., Nelson, S., Mueller, U. & Malaga, K. (2016). Durability of concrete exposed to sea water at early age: Flotaing dock method for construction of caissons. In: Proceedings of the Second International Conference on Concrete Sustainability: . Paper presented at Second International Conference on Concrete Sustainability,ICCS16, held in Madrid, Spain on 13–15 June 2016 (pp. 250-260). International Center for Numerical Methods in Engineering (CIMNE)
Open this publication in new window or tab >>Durability of concrete exposed to sea water at early age: Flotaing dock method for construction of caissons
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2016 (English)In: Proceedings of the Second International Conference on Concrete Sustainability, International Center for Numerical Methods in Engineering (CIMNE) , 2016, p. 250-260Conference paper, Published 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.                

Place, publisher, year, edition, pages
International Center for Numerical Methods in Engineering (CIMNE), 2016
Keywords
Caissons, concrete, durability, maritime environment, chloride
National Category
Civil Engineering Materials Engineering
Identifiers
urn:nbn:se:ri:diva-27815 (URN)978-84-945077-7-9 (ISBN)
Conference
Second International Conference on Concrete Sustainability,ICCS16, held in Madrid, Spain on 13–15 June 2016
Available from: 2017-01-10 Created: 2017-01-10 Last updated: 2018-08-15Bibliographically approved
Williams Portal, N., Zandi, K., Malaga, K. & Wlasak, L. (2016). GFRP connectors in textile reinforced concrete sandwich elements. In: IABSE Congress Stockholm, 2016: Challenges in Design and Construction of an Innovative and Sustainable Built Environment. Report. Paper presented at 19th IABSE Congress Stockholm, Sweden, 21-23 September 2016. (pp. 1331-1338). IABSE c/o ETH Hönggerberg
Open this publication in new window or tab >>GFRP connectors in textile reinforced concrete sandwich elements
2016 (English)In: IABSE Congress Stockholm, 2016: Challenges in Design and Construction of an Innovative and Sustainable Built Environment. Report, IABSE c/o ETH Hönggerberg , 2016, p. 1331-1338Conference paper, Published paper (Refereed)
Abstract [en]

In this paper, both experimental and numerical methods are presented to gain an understanding of the structural behaviour related to a TRC sandwich panel with a glass fibre reinforced polymer (GFRP) plate connection system. Double shear tests were conducted on component-scale sandwich panels to characterize the available shear capacity provided by the connectors and panel configuration. Three-dimension (3D) non-linear Finite Element Analysis (NLFEA) was applied to develop a model for the design of TRC sandwich panels while focusing on the connectors. The experimental outcome of the shear tests was applied to validate the corresponding numerical model developed in this work. The need for further modifications to the design of the shear connectors or other parameters such as panel thickness can be established accordingly. This developed FE model can essentially be applied as a design tool to further predict the structural behaviour of the full-scale sandwich elements.

Place, publisher, year, edition, pages
IABSE c/o ETH Hönggerberg, 2016
Keywords
sandwich elements, textile reinforced concrete (TRC), glass fibre reinforced polymer (GFRP), shear connectors, experiments, finite element analysis (FEA)
National Category
Civil Engineering Applied Mechanics Composite Science and Engineering
Identifiers
urn:nbn:se:ri:diva-27810 (URN)978-3-85748-144-4 (ISBN)
Conference
19th IABSE Congress Stockholm, Sweden, 21-23 September 2016.
Available from: 2017-01-10 Created: 2017-01-10 Last updated: 2018-08-15Bibliographically approved
Williams Portal, N., Flansbjer, M., Johannesson, P., Malaga, K. & Lundgren, K. (2016). Tensile behaviour of textile reinforcement under accelerated ageing conditions. Journal of Building Engineering, 5, 57-66
Open this publication in new window or tab >>Tensile behaviour of textile reinforcement under accelerated ageing conditions
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2016 (English)In: Journal of Building Engineering, ISSN 2352-7102, Vol. 5, p. 57-66Article in journal (Refereed) Published
Abstract [en]

Textile reinforced concrete (TRC) has emerged as a promising alternative wherein corrosion is no longer an issue and much thinner and light-weight elements can be designed. Although TRC has been expansively researched, the formalization of experimental methods concerning durability arises when attempting to implement and design such innovative building materials. In this study, accelerated ageing tests paired with tensile tests were performed. The change in physico-mechanical properties of various commercially available textile reinforcements was documented and evaluated. The ability for the reinforcements to retain their tensile capacity was also quantified in the form of empirical degradation curves. It was observed that accelerated test parameters typically applied to fibre-reinforced polymer (FRP) bars and grids are generally too aggressive for the textile reinforcement products and alternative boundary conditions are necessary. The developed degradation curves were found to have an overall good correlation with the experimental findings.

Place, publisher, year, edition, pages
Elsevier, 2016
Keywords
accelerated ageing, durability, experimental tests, tensile testing, textile reinforced concrete
National Category
Building Technologies Composite Science and Engineering
Identifiers
urn:nbn:se:ri:diva-105 (URN)10.1016/j.jobe.2015.11.006 (DOI)2-s2.0-84949591056 (Scopus ID)
Available from: 2016-05-24 Created: 2016-04-28 Last updated: 2018-08-16Bibliographically approved
Mueller, U., Lundgren, M. & Malaga, K. (2015). Development of pore structure and hydrate phases of binder pastes blended with slag, fly ash and metakaolin – A comparison. In: The 14th International Conress on the Chemistry of Cement: . Paper presented at The 14th International Congress on the Chemistry of Cement.
Open this publication in new window or tab >>Development of pore structure and hydrate phases of binder pastes blended with slag, fly ash and metakaolin – A comparison
2015 (English)In: The 14th International Conress on the Chemistry of Cement, 2015Conference paper, Published paper (Refereed)
Keywords
Conference
National Category
Building Technologies
Identifiers
urn:nbn:se:ri:diva-34059 (URN)
Conference
The 14th International Congress on the Chemistry of Cement
Available from: 2018-07-05 Created: 2018-07-05 Last updated: 2018-08-15Bibliographically approved
Vera-Agullo, J., Castro-Visos, F. M., Larraz-Bordanaba, F. J., Troncone-Cusati, C., Asencio-Varela, J. P., Silva, N., . . . Malaga, K. (2015). Durability of concrete caissons made in floating docks. In: 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”. Paper presented at 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”, Melbourne, Australia, August 30-September 2, 2015 (pp. 894-903). Institute of Australia
Open this publication in new window or tab >>Durability of concrete caissons made in floating docks
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2015 (English)In: 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, Published 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.

Place, publisher, year, edition, pages
Institute of Australia, 2015
Keywords
concrete, caissons, durability, chlorides, nanosilica
National Category
Civil Engineering
Identifiers
urn:nbn:se:ri:diva-378 (URN)978-1-943847-70-9 (ISBN)
Conference
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”, Melbourne, Australia, August 30-September 2, 2015
Available from: 2016-06-20 Created: 2016-06-20 Last updated: 2018-08-15Bibliographically approved
Identifiers
ORCID iD: ORCID iD iconorcid.org/0000-0001-9867-7631

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