Search

Copper has been chosen as the outermost material used in the canister in Finnish nuclear waste disposal program. In anoxic water, the corrosion of copper should be extremely slow. However, microbial activity on the surface of the copper canister or in the vicinity of the canister can enhance corrosion in many different ways, e.g. changing the pH or redox potential, excretion of corrosivemetabolites, direct or indirect reduction or oxidation of corrosion products and formation of biofilms. In this study the later stage of the deep geological nuclear waste repository was simulated. In that stage all oxygen introduced at the construction stage has been consumed and the temperature in the repository has decreased to the level of the surrounding bedrock. It is also assumed that the copper is in direct contact with the groundwater. We studied the microbially influenced corrosion (MIC) of copper sheets in the simulation usingelectrochemical technologies, weight loss measurements and molecular biology methods in the laboratory. The chemistry of the used synthetic water was calculated to simulate the groundwater of disposal site also including the effects of bentonite, which will be used as buffer in the repository. Inoculations of sulfate reducing bacteria (SRB) and methanogens enriched from the disposal site were added to the biotic experiments. A sterilized abiotic environment was used as a reference. Preliminary results of the first year´s incubation studies are discussed in this paper.

Results of microbiological and geochemical sampling in the Outokumpu deep (2.5 km) borehole are presented. The results indicate that the discharging fractures control the observed variations in the microbial populations at different depths, which evidently reflect true variations in the microbial populations in fractures of the crystalline bedrock.

Closed-cell polyisocyanurate (polyiso) foam insulation with gas barriers or impermeable facers is used in various building envelope applications. The impermeable gas barrier on both sides of polyiso foam insulation board is designed to maintain the long-term thermal resistance (LTTR) of the insulation at a higher level. Recently, researchers at the Institute for Research in Construction (IRC) / National Research Council (NRC) of Canada, in association with the Canadian Polyisocyanurate Council, have been working to develop a standard test methodology that would help to quantify the design LTTR value of polyiso foam insulation boards with impermeable facers. This paper presents selected results from laboratory tests, field observations and numerical modeling. Comparisons among these results indicate that the extent of thermal aging of impermeably faced polyiso foam boards can vary in different products. A concept of combined lateral and normal diffusion has been introduced in the numerical modeling to help prediction of the long-term thermal behavior of impermeably faced polyiso products. However, comparisons between the experimental and numerical modeling results indicate that the ratio of lateral to normal (L/N) diffusion rate is not the same for full thickness boards as for thin slices., IX International Conference on Performance of Exterior Envelopes of Whole Buildings: 05 December 2004, Clearwater Beach, Florida

By 1997, several field surveys in North America had indicated that rain penetration in exterior walls and poor construction detailing contributed to the shortening of the service life of recently built exterior walls of low-rise buildings in climates with high exterior moisture loads. There was a movement in industry to rethink the ways that exterior walls had been put together in recent years, as well as a renewed appreciation that exterior climates vary in severity from one location to another. In 1998, IRC/NRC initiated a research consortium with industry partners to develop guidelines for moisture management for exterior wall systems (MEWS) in low-rise residential buildings of North America. Partners represented the wood industry, manufacturers of cladding systems, insulation materials and water resistive barriers as well as building owners and managers. The project was broken down into several tasks, from a review of literature on current construction practice to experimental work in the laboratory and mathematical modelling. The following four types of cladding systems were included in the project: Portland cement plaster (stucco), Exterior Insulation and Finish Systems (EIFS), masonry and siding, over wood-frame construction.This TG8 report is a research document. The objectives of the report are three-fold: to describe the research approach in some detail (chapter 1), to summarize its application to the four types of wall assemblies (chapters 2 - 5) and to draw general conclusions (chapter 6), based on the observations in chapters 2 - 5. The reader is strongly advised to consult the research team before the information presented in this report is used for building design considerations.

From late 1999 to early 2001, seventeen large-scale wall specimens were built for water entry investigation in IRC Dynamic Wall Testing facility (DWTF). The specimens consisted of five stucco-clad, five Exterior Insulation and Finish system (EIFS)-clad, four masonry-clad and three siding-clad assemblies (two hardboard and one vinyl). All specimens included a window, a duct and an electrical outlet receptacle. The composition of the specimens is described with wall section drawings and photographic records of their construction.

The objective of this report is to communicate, in a very concise form, some of the accomplishments of the MEWS (Moisture Management for Exterior Wall Systems) project. This will be done in terms of the research methodology adopted, as well as the outcome of its application to the first type of walls analysed in the project - Stucco-clad exterior wood-frame wall assemblies. Only a few examples will be cited in this report. Many reports have been produced detailing the process followed and the results obtained. The interested reader is welcome to refer to these documents for a more detailed investigation of any selected topics.

Performance of Exterior Envelopes of Whole Building VIII: Integration of Building Envelopes: 02 December 2001, Clearwater Beach, FL

International Conference on Building Envelope Systems and Technologies ICBEST 2001: 26 June 2001, Ottawa, ON

Exterior basement insulation performs many functions. It not only provides thermal resistance between the soil and the interior, it also protects the structure from a challenging environment (e.g. moisture from wet soils, heaving and adhering soils due to frost action). It provides a means of water management at the interface of the soil and insulation, while promoting drying out of the structure. In this context, it is important to set performance parameters for setting appropriate materials. The Canadian Urethane Foam Contractors Association established a joint research project with the Institute for Research in Construction to assess the in-situ thermal performance of Spray Polyurethane Foam (SPF) applied to the exterior of a basement.

Exterior basement insulation performs many functions. It not only provides thermal resistance between the soil and the interior, it also protects the structure from a challenging environment (e.g. moisture from wet soils, heaving and adhering soils due to frost action). It provides a means of water management at the interface of the soil and insulation, while promoting drying out of the structure. In this context, it is important to set performance parameters for setting appropriate materials. The Canadian Urethane Foam Contractors Association established a joint research project with the Institute for Research in Construction to assess the in-situ thermal performance of Spray Polyurethane Foam (SPF) applied to the exterior of a basement., L'isolation extérieure du sous-sol remplit de nombreuses fonctions. Elle fournit non seulement une résistance thermique entre le sol et l'intérieur, mais aussi protège la structure contre un environnement rigoureux (p. ex. l'humidité des sols détrempés, le soulèvement et l'adhérence du sol en raison du gel). Elle constitueun moyen de maîtrise de l'eau à l'interface du sol et de l'isolant, tout en favorisant l'assèchement de la fondation. Étant donné cette multitude de fonctions, il est important de définir des paramètres de performance afin d'utiliser les matériaux appropriés. La Canadian Urethane Foam Contractors Association et l'Institut de recherche en construction ont lancé un projet de recherche conjoint visant à évaluer laperformance thermique en service de la mousse de polyuréthane pulvérisée (MPP) appliquée sur l'extérieur des murs de sous-sol., Also available in English: In-situ performance evaluation of exterior insulation basement system (EIBS) - Spray polyurethane foam summary report

A consortium research project was initiated to determine the field performance of various thermal insulation products as applied in the exterior insulation basement system (EIBS). Initially a two-dimensional analytical tool was used to derive the thermal transmission characteristics from an array of temperature measurements monitored over a period of two years. Results immediately showed the influence of lateral heat flux between various products that differed in thermal transmission properties. Therefore, development of a three dimensional model became imperative, to resolve the order of magnitude of the lateral heat flux in the experimental set-up, and determine the actual in-situ properties of the insulation specimens. This report gives the theoretical and numerical approaches adopted to develop a three-dimensional computer model of heat transfer. The implicit Spline Method was selected for the problem solver. The applicability of the model was verified using measured data on temperature distributions at several material interfaces. Then the model was used to estimate the effect of lateral heat flows, and to determine the in-situ thermal properties of the insulation specimens. The report also records experimental details and presents validation results of the analytical approach.

This work is an extension of the project 'Exterior Insulation Basement Systems' (EIBS), a joint research project initiated by Canadian Plastics Industry Association, Expanded Polystyrene Association of Canada, Canadian Urethane Foam Contractors Association, Owens Corning Inc. and Roxul Inc. This project assesses the in situ performance - above and below grade - of several exterior insulation specimens.The experimental set-up and instrumentation and data collection have been completed. The analysis indicated that the heat flows from below-grade to above-grade portion of the basement wall to outdoors in cold weather. As well, the majority of heat loss through steel studs on the east wall appears to be above-grade. Therefore, a three-dimensional heat transfer analysis has been undertaken and heat loss analysis must be extended above grade and past the guards, in order to assess the magnitude of these heat flows.In the summer of 1997, additional thermocouples set were placed above grade and at the guard locations at the south end of each east and west walls at Test Hut #1. This internal report concerns the analysis of this additional data. This project is outside the scope of the original EIBS project.

International Building Physics Conference (IBPC): 00 September 2000, Eindhoven

Spray-polyurethane foams (SPFs) are thermally efficient and can be sprayed to any thickness to provide the desired thermal resistance. Hence, SPFs have proven themselves as insulation for roofs, walls, ducts and pipes in district heating. They also make good air barriers and vapour retarders. While SPFs may represent an ideal building material, some caveats regarding thermal drift or aging and moisture performance must nevertheless be observed. Designers can mitigate both causes for concern by, among other things, adjusting the thickness of the layer of SPFs to be applied.

L'intérêt d'une isolation extérieure des sous-sols réside dans le fait qu'elle offre un contrôle du transfert thermique et une maîtrise des eaux souterraines. Dans une étude menée par l'IRC, tous les produits testés, polystyrène expansé (EPS), mousse de polyuréthane projetée (MPP) ou panneau de fibres minérales, ont affiché une performance thermique plus ou moins identique, indépendamment des mouvements d'eau enregistrés sur la face extérieure des isolants. L'eau n'a jamais atteint le mur de fondation et même, dans le cas de l'utilisation de MPP, la semelle est restée sèche. Les panneaux isolants adjacents doivent être très bien ajustés côte à côte pour empêcher toute pénétration d'eau au niveau des joints. Un soin particulier sera apporté pour éviter de créer des ponts thermiques pouvant entraver la performance thermique.

La mousse de polyuréthane pistolée (MPP) est efficace sur le plan thermique et peut être appliquée en épaisseurs variables de manière à assurer la résistance thermique recherchée. Elle a fait ses preuves comme isolant de toit, de mur, ainsi que de conduits et tuyauterie d'installations de chauffage centralisé. Elle forme aussi de bons pare-air. La MPP peut constituer un matériau de construction idéal, mais il faut prendre garde à certains points, dont la dérive thermique (vieillissement) et la performance hygrométrique de ce type de mousse. Pour remédier en partie à ces problèmes, les concepteurs peuvent notamment faire varier l'épaisseur de la couche de MPP à appliquer.

Exterior basement insulation matters most in heat-loss control and groundwater management. In an IRC study, all products tested, whether EPS, spray-polyurethane foam (SPF) or mineral-fibre board, performed more or less equally well from a thermal standpoint. And that regardless of water movement recorded at the outer face of the insulation. In no case did water reach the foundation wall, and where SPF was used, even the footing remained dry. Adjacent insulation boards must be tightly installed beside one another to stave off any ingress of water at the joints. Care must also be taken to avoid thermal bridges, which can erode thermal performance.

Proceedings of CIB W40 Meeting: 30 August 1999, Prague, Czech Republic

The Canadian approach to design accepts the presence of some construction deficiencies and calls for a multiple-line of defense. Until now, such a design has been based on the qualitative assessments rooted in experience, i.e., tradition, and involved little integration with the newly emerging analytical tools, e.g., advanced hygrothermal models. The relation between the design and climatic conditions acting on a building is not well established. Research should be undertaken to clarify the relationship between climate and the moisture performance of a given wall assembly, i.e. to enhance the predictability of moisture performance for different wall assemblies when constructed with some deficiencies and exposed to a given climate.

Seventh Conference on Building Science and Technology: 20 March 1997, Toronto, Ontario

Proceedings of the Seventh Conference on Building Science and Technology : Durability of Buildings - Design, Maintenance, Codes, and Practices: 20 March 1997, Toronto, Ontario, Canada