Hygrothermal performance of a brick wall with interior insulation in cold climate: Vapour open versus vapour tight approach

2021 ◽  
pp. 174425912110560
Author(s):  
Paul Klõšeiko ◽  
Targo Kalamees
Keyword(s):  
Material Properties ◽  
Material Characterization ◽  
Capillary Condensation ◽  
Frost Damage ◽  
Cold Climate ◽  
Critical Conditions ◽  
Dramatic Improvement ◽  
Brick Wall ◽  
Insulation System ◽  
Material Data

Interior insulation of historic buildings is well-studied in Central Europe; however, their conclusions might not be directly applicable to colder climates. Heat, air and moisture (HAM) modelling can be a valuable tool for studying those solutions in different conditions. Recently, incorporating the capillary condensation redistribution (CCR) test into the material characterization process has shown to cause dramatic improvement in correlating hygrothermal modelling results to measurements in certain situations. It is also noteworthy, that the HAM modelling errors made using material data from conventional characterization process can be severely non-conservative. In this article a parametric study of a 51 cm thick mass masonry wall is undertaken to determine the effect of the improved material properties on the reliability of a vapour open ‘capillary active’ autoclaved aerated concrete (AAC) and calcium silicate (CaSi) interior insulation solutions and to compare them to a vapour tight insulation system. A 49-year real weather dataset from Estonia is used. The results show that compared to conventionally characterized material properties the CCR-optimized material data causes more critical conditions directly behind the interior insulation, while having a similar performance in the exterior part of the masonry. The differences occur close to the performance limits and highlight the importance of using the CCR test in material characterization process. The vapour tight and vapour open systems showed a very similar impact on the freeze-thaw cycles and on the maximum ice saturation of the exterior part of the masonry. The vapour open solutions perform better than the vapour tight PIR in terms of frost damage and possible mould growth behind the insulation – even though the advantage has been reduced when using the CCR-optimized material data. Regardless of the insulation solution, a case-specific approach is still required to avoid damaging the original wall and/or the added insulation system.

Scatter in Dwell Time Cracking for a Ni-Based Superalloy in Combination With Overloads

2015 ◽  
Author(s):  
Erik Storgärds ◽  
Jonas Saarimäki ◽  
Kjell Simonsson ◽  
Sören Sjöström ◽  
David Gustafsson ◽  
...  
Keyword(s):  
Growth Rate ◽  
High Temperature ◽  
Crack Growth ◽  
Material Properties ◽  
Inconel 718 ◽  
Dwell Time ◽  
The Other ◽  
Surface Cracks ◽  
Multiple Tests ◽  
Material Data

In this paper scatter in crack growth for dwell time loadings in combination with overloads has been investigated. Multiple tests were performed for surface cracks at 550°C in the commonly used high temperature material Inconel 718. The test specimens originate from two different batches which also provides for a discussion of how material properties affect the dwell time damage and overload impact. In combination with these tests an investigation of the microstructure was also carried out, which shows how it influences the growth rate. The results from this study show that, in order to take overloads into consideration when analysing spectrum loadings containing dwell times, one needs a substantial amount of material data available as the scatter seen from one batch to the other is of significant proportions.

STYLE: Study on Transferability of Fracture Material Properties From Small Scale Specimens to a Real Component

2011 ◽  
Author(s):  
Tomas Nicak ◽  
Herbert Schendzielorz ◽  
Elisabeth Keim ◽  
Gottfried Meier
Keyword(s):  
Fracture Mechanics ◽  
Material Properties ◽  
Large Scale ◽  
Fracture Behaviour ◽  
Experimental Investigations ◽  
Small Scale ◽  
Real Component ◽  
Material Data ◽  
Analytical Work ◽  
Constraint Effects

This paper describes numerical and experimental investigations on transferability of material properties obtained by testing of small scale specimens to a real component. The presented study is related to the experimental and analytical work performed on Mock-up3, which is one of three unique large scale Mock-ups tested within the European project STYLE. Mock-up3 is foreseen to investigate transferability of material data, in particular fracture mechanics properties. An important part of this work is to study constraint effects on different small scale specimens and to compare their fracture behaviour with the fracture behaviour of a large scale (component like) structure. The Mock-Up3 is an original part of a surge line made of low alloy steel 20 MnMoNi 5 5 (which corresponds to SA 508 Grade 3, Cl. 1). The goal of the test is to introduce stable crack growth of an inner surface flaw until a break through the wall occurs. To design such a test reliable fracture mechanics material properties must be available. Usually, these material data are obtained by testing small specimens, which are subsequently used for the assessment of a large scale structure (component). This is being done under the assumption that these “small scale” material properties are fully transferable to “large scale” components. It is assumed that crack initiation in the ductile tearing regime is rather independent of the crack shape, a/W ratio, loading condition or size of the specimen (constraint effects). In order to check the aforementioned assumption and to improve understanding of the physical process leading to failure of cracked components comprehensive experimental and analytical work is being undertaken in STYLE. This paper summarizes Up-To-Date available results, which have been achieved during the first 15 months of the project.

Effects of Texture on Thermoelectric Power in Ti-6Al-4V

2006 ◽  
Author(s):  
Hector Carreon
Keyword(s):  
Thermoelectric Power ◽  
Material Properties ◽  
Material Characterization ◽  
Grain Structure ◽  
Power Dependence ◽  
Anisotropic Behavior ◽  
Nondestructive Technique ◽  
Parallel Direction ◽  
Polycrystalline Microstructure ◽  
Power Measurements

Ti-6A1-4V alloy exhibits a very strong anisotropic texture caused by the existence of a preferred crystallographic orientation in the polycrystalline microstructure. This crystallographic alignment can result in anisotropic behavior of the material so that the material properties are different depending on whether they are measured in perpendicular or parallel direction. In addition to this morphological anisotropy, due to the dominantly hexagonal grain structure, the Ti-6A1-4V alloy also exhibited a substantial thermoelectric anisotropy. This study was conducted to investigate the effect of thermoelectric anisotropy on the thermoelectric power measurements in a highly textured Ti-6A1-4V specimen using a completely nondestructive technique based on the Seebeck effect. The result shows the thermoelectric power dependence associated with texturing and the macroscopic grain structure in a rolled Ti-6A1-4V specimen, which was annealed at 710°C for 2 hours and slowly cooled. The measurements clearly demonstrated that the intrinsic sensitivity of the thermoelectric contact technique is a very useful tool that could be exploited for quantitative nondestructive (QND) material characterization.

Basic Polymer Material Properties for Flame Spread

1993 ◽  
Vol 11 (4) ◽  
pp. 287-295 ◽  
Author(s):  
M.A. Delichatsios
Keyword(s):  
Flame Spread ◽  
Material Properties ◽  
Oxygen Index ◽  
Fire Hazard ◽  
Fire Spread ◽  
Test Methods ◽  
Critical Conditions ◽  
Small Scale ◽  
Limited Oxygen Index ◽  
Limited Oxygen

We present and demonstrate the application of a systematic methodology for predicting fire spread and growth and for a relative fire hazard classification of materials for any scale and fire environment. This methodol ogy consists of three steps: (1) select laboratory test methods to perform flam mability measurements; (2) based on these measurements, obtain key flamma bility material properties which are precisely defined in this work; and (3) use these properties in a mathematical model of fire spread and growth to predict fire hazards. The complementary test methods we have selected and used are: (a) a general flammability test apparatus (such as NIST or FMRC) [1,2] modified to also provide pyrolysis measurements in an inert N2 atmosphere; (b) the Limited Oxygen Index (LOI) apparatus, which is used here as a tool for ob taining properties needed for creeping flame spread and extinction, including vitiated environments; and (c) a solid material smoke-point height apparatus [8], which is used to characterize the smokiness of the burning material needed to determine the radiation and smoke yield for arbitrary fire situations (wall fires, pool fires or ceiling fires) [8]. The use and proper interpretation of the Limited Oxygen Index apparatus can replace the LIFT [10] apparatus for deter mining in a more accurate and direct way the material properties required for creeping (vertical downward, lateral, horizontal) flame spread. The present methodology has been compared well with experiments in this work and else where [9], and it has been used to predict critical conditions for fire spread [11], not empirically as it is usually done, but based on first principles of fire spread, fire growth and burning, together with material flammability properties syste matically deduced from small-scale test measurements.

scholarly journals The transverse and longitudinal elastic constants of pulp fibers in paper sheets

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Caterina Czibula ◽  
August Brandberg ◽  
Megan J. Cordill ◽  
Aleksandar Matković ◽  
Oleksandr Glushko ◽  
...  
Keyword(s):  
Material Properties ◽  
Material Characterization ◽  
Industrial Process ◽  
Cellulose Fibers ◽  
Mechanical Modeling ◽  
Pulp Fibers ◽  
Fiber Properties ◽  
The Individual ◽  
Longitudinal Modulus

AbstractCellulose fibers are a major industrial input, but due to their irregular shape and anisotropic material response, accurate material characterization is difficult. Single fiber tensile testing is the most popular way to estimate the material properties of individual fibers. However, such tests can only be performed along the axis of the fiber and are associated with problems of enforcing restraints. Alternative indirect approaches, such as micro-mechanical modeling, can help but yield results that are not fully decoupled from the model assumptions. Here, we compare these methods with nanoindentation as a method to extract elastic material constants of the individual fibers. We show that both the longitudinal and the transverse elastic modulus can be determined, additionally enabling the measurement of fiber properties in-situ inside a sheet of paper such that the entire industrial process history is captured. The obtained longitudinal modulus is comparable to traditional methods for larger indents but with a strongly increased scatter as the size of the indentation is decreased further.

scholarly journals Hygrothermal performance of internally insulated masonry walls with embedded wooden beam heads: a field study on the impact of hydrophobisation

2021 ◽  
Vol 2069 (1) ◽  
pp. 012019
Author(s):  
E Vereecken ◽  
S Roels
Keyword(s):  
Relative Humidity ◽  
Field Study ◽  
Open System ◽  
Frost Damage ◽  
Masonry Walls ◽  
Insulation System ◽  
Hygrothermal Performance ◽  
Potential Measure ◽  
Moisture Conditions ◽  
The Impact

Abstract Internal insulation remains often the only option to thermally upgrade massive masonry. Unfortunately, internal insulation can significantly change the wall’s hygrothermal performance, resulting in a higher risk on frost damage, wood rot of embedded beam heads, etc. The application of hydrophobisation is often put forward as a potential measure to avoid moisture problems, though more research on the impact of hydrophobisation is still required. Thereto, the current paper presents the results of a field study on the hygrothermal performance of internally insulated masonry with embedded wooden beam heads, exposed to wind-driven rain. Both a vapour open capillary active and a vapour tight insulation system are studied. Mainly the moisture conditions near the back of the wooden beam head are found to be influenced by hydrophobisation, which lowers the relative humidity. Closer to the masonry’s interior surface, the choice of the insulation system also influences the results. In case of a well-applied hydrophobisation, overall, the vapour tight system shows a better performance than the capillary active vapour open system. An exception to this is found for the first months after applying the hydrophobisation and the insulation system, where a longer drying period is needed in case of the vapour tight system.

STYLE: Transferability of Fracture Material Properties - Updated Experimental and Analytical Results

2012 ◽  
Author(s):  
Tomas Nicak ◽  
Herbert Schendzielorz ◽  
Elisabeth Keim ◽  
Gottfried Meier ◽  
Dominique Moinereau ◽  
...  
Keyword(s):  
Fracture Mechanics ◽  
Material Properties ◽  
Large Scale ◽  
Small Scale ◽  
Outer Diameter ◽  
Real Component ◽  
Material Data ◽  
Analytical Results ◽  
Grade 3 ◽  
Original Part

This paper describes new results of the STYLE study on investigations of transferability of fracture material properties obtained by testing of small scale specimens to a real component. In STYLE there are three large scale mock-up tests each of them dedicated to investigate specific effects. Mock-up3 (cladded ferritic pipe with the outer diameter of 424 mm) is foreseen to investigate transferability of material data, in particular to compare fracture mechanics behavior of small specimens under different constraint conditions with a full size component. The Mock-Up3 is an original part of a surge line made of low alloy steel (20MnMoNi55 which corresponds to SA 508 Grade 3, Cl. 1). Usually, material data necessary for fracture mechanic analyses are obtained by testing small specimens, which are subsequently used for the assessment of large scale structures (real components). This approach is believed to be conservative since the material properties are obtained on highly constrained standard specimens. In this paper new experimental and analytical results will be presented (including tests on constraint modified specimens and a comparison of these results with the Mock-up3 test). The overall objective is to investigate the influence of specimen size, crack shape and type of loading on fracture mechanics properties like crack initiation load or amount of the crack growth by means of numerical analyses and compared with experimental results.

Thermal Environment of Traditional Dwelling Houses in Dry Hot and Dry Cold Climate Zone of China in Winter

2011 ◽  
Vol 243-249 ◽  
pp. 178-183
Author(s):  
Deng Jia Wang ◽  
Yan Feng Liu ◽  
Jia Ping Liu ◽  
Jing Hua Liu
Keyword(s):  
Thermal Environment ◽  
Good Practice ◽  
Gansu Province ◽  
Cold Climate ◽  
Brick Wall ◽  
Indoor Temperature ◽  
Indoor Thermal Environment ◽  
Solar Radiation Intensity ◽  
Wind Chill Index ◽  
Indoor And Outdoor

In order to master the indoor thermal environment of the traditional dwelling houses in dry hot and dry cold climate zones in winter, the east Gansu province is taken for example to study. Indoor and outdoor air temperature, relative humidity, solar radiation intensity and wind speed were obtained by using field-tested methods for the traditional dwelling houses in this region in winter, and the clothing form and activity of people were surveyed by way of questionnaire. And then, the influence of house orientation, indoor heat sources and insulation on the indoor thermal environment is analyzed, the WCI (wind chill index) is used to evaluate the indoor and outdoor thermal environment at last. The results show that: the indoor temperature can raise about 8.3 °C when the house orientation is better and Chinese kang as the heating heat source. The good practice on local structure is worthy of following for other houses, such as adobe posted solid brick wall, double windows, wooden sash windows and so on. However, people still feel very cool or cold about the indoor temperature for much of the day, and even people feel very cold for 5% of the day. At the end of thesis, some methods about the indoor thermal environment improvement are proposed.

Materials Characterization and Synthesis of Conductive Aromatic-Bis(Benzothiazoles)

2001 ◽  
Vol 665 ◽  
Author(s):  
Max D. Alexander ◽  
Balasubramanian Sankaran ◽  
B. Robert McKellar ◽  
Douglas S. Dudis
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Fourier Transform ◽  
Electron Spin Resonance ◽  
Magnetic Resonance ◽  
Direct Current ◽  
Material Properties ◽  
Material Characterization ◽  
Materials Characterization ◽  
Spin Resonance ◽  
Synthetic Approaches

ABSTRACTFunctionalized aromatic-bis(benzothiazoles) have been synthesized by our group and have shown promise as conductive n-dopable polymers and oligomers. When reduced (n-doped) these materials typically exhibit conductivity on the order of tens of S/cm. Here we examine the material properties of this family of derivatized, conductive aromatic-bis(benzothiazoles). A variety of synthetic approaches have been examined to produce these polymers and oligomers, and will be discussed. Material characterization has been accomplished by spectro-electrochemistry, nuclear magnetic resonance (NMR), electron spin resonance (ESR), Fourier Transform Infrared (FTIR) spectroscopy, and direct current (DC) conductivity.

Sign in / Sign up

Export Citation Format

Share Document