The influence of visual assessment grade on the residual flexural capacity of 46 existing precast... more The influence of visual assessment grade on the residual flexural capacity of 46 existing precast concrete ribbed panels was studied. Before the tests, the panels were assessed on a 6-point rating scale according to visually distinguishable corrosion deterioration. All panels, the ultimate load of which was lower than the control load, received grade 0 on visual rating scale. Consequently, attention should be paid to panels where the concrete cover of longitudinal reinforcement has spalled (grade 0), which could be a sign of decreasing load capacity. The majority of panels with grade 0 exhibited larger deflections under load than panels with higher grades. Of the 46 panels tested flexural ductile failure was noticed in 36 panels.
Desalination using clay and lime sacrificial plasters with additives on field stone wall and fired clay bricks
Journal of Physics: Conference Series, 2021
Salt deteriorations can ruin the appearance as well as the structure of buildings. Salt deteriora... more Salt deteriorations can ruin the appearance as well as the structure of buildings. Salt deteriorations can be mitigated by passive and active methods. Common active methods include sprinkling water on the structure, scraping off the concentrated salts from the surface and the use of sacrificial plasters. Sacrificial plasters are traditionally used for desalination. Two tests at different sites were performed in order to determine the effectiveness of desalination of different sacrificial plasters. The first test site was a two hundred years old stable wall in Mooste county, Estonia. Salt percentage by mass in the test wall was determined in 2017 and again in 2019. In December 2019 different plasters of local natural clay and lime with additives such as hemp flax, charcoal and turf were tested on the wall. The second test was performed on burnt clay bricks that were placed into salt solution until efflorescence appeared. For desalination process again, different clay and lime based s...
Ilmastonmuutoksen hillitseminen edellyttää kansallisia ja kansainvälisiä toimia. Rakennussektoril... more Ilmastonmuutoksen hillitseminen edellyttää kansallisia ja kansainvälisiä toimia. Rakennussektorilla on arvioiden mukaan eniten potentiaalia pienentää kasvihuonekaasupäästöjä. Asuinrakennusten osuus rakennussektorin energiankulutuksesta on noin 27 %. Euroopan unionin energiatehokkuusdirektiivi ja rakennusten energiatehokkuusdirektiivi (EPBD) ovat merkittävimmät lainsäädännölliset keinot, joilla pyritään parantamaan uusien ja olemassa olevien rakennusten energiatehokkuutta. Direktiivejä toteutetaan erilaisin kansallisin säädöksin ja ohjelmin, joissa tavallisimmin keskitytään vähentämään rakennusten energiankulutusta. Energiatehokkuuden parantaminen voi kuitenkin vaikuttaa myös sisäympäristön laatuun sekä asukkaiden terveyteen ja hyvinvointiin, joskin tutkimustietoa asiasta on niukasti. tavoitteena oli selvittää asuinrakennusten energiatehokkuuden parantamisen vaikutuksia rakennukseen, sisäilman laatuun ja asukkaiden terveyteen sekä kehittää kokonaisvaltainen malli näiden vaikutusten arviointiin. Viisivuotisessa hankkeessa (2010-2015) tutkittiin energiakorjausten vaikutuksia lukuisissa rakennuksissa Suomessa ja Liettuassa (alueet, joilla rakennukset sijaitsevat, on merkitty kuvaan 1). Kuva 1. Tutkimuspaikat sekä tutkimuksessa mukana olleiden rakennusten sijainnit Suomessa ja Liettuassa.
Background: Driven by climate change mitigation, EU countries are committed to improve energy eff... more Background: Driven by climate change mitigation, EU countries are committed to improve energy efficiency of their building stock by implementing the energy performance of buildings directive (EPBD). Should higher energy efficiency result in better indoor environmental quality (IEQ), this policy could also be seen as an opportunity to improve public health across Europe. Objectives: This paper focuses on the assessment of the effects of energy retrofits on occupant satisfaction with IEQ and health in multifamily buildings. Methods: Data on occupant satisfaction with IEQ and health were collected from the occupants of 39 Finnish and 15 Lithuanian multifamily buildings (an average of five apartments per building, one adult per apartment) both before and after energy retrofits (such as improving thermal insulation, windows, heating and/or ventilation systems). Parallel to the data collected from the occupants, data on several IEQ parameters, including temperature, temperature factor, and air change rate, were collected from their apartments. Moreover, data from seven Finnish and five Lithuanian non-retrofitted control buildings were collected according to the same protocol. Results: Occupant satisfaction regarding indoor temperature was associated with both retrofit status (OR 5.3, 95% CI 2.6-11.0) and measured IEQ parameters (indoor temperature OR 1.4 per 1 °C increase, temperature factor OR 1.1 per 1% increase, and air change rate OR 5.6 per 1/h increase). Additional positive associations were found between retrofit status and occupants reporting absence of upper respiratory symptoms (OR 1.8, 95% CI 1.1-2.9) as well as not missing work or school due to respiratory infections (OR 4.1, 95% CI 1.2-13.8), however, these associations were independent of the measured IEQ parameters. Conclusions: There seems to be a strong subjective component related to the observed changes in occupant satisfaction with IEQ and health as a result of energy retrofitting in buildings. Further studies are needed to verify the actual mechanisms, as well as possible long term effects.
Desalination using clay and lime sacrificial plasters with additives on field stone wall and fired clay bricks
Journal of physics, Nov 1, 2021
Salt deteriorations can ruin the appearance as well as the structure of buildings. Salt deteriora... more Salt deteriorations can ruin the appearance as well as the structure of buildings. Salt deteriorations can be mitigated by passive and active methods. Common active methods include sprinkling water on the structure, scraping off the concentrated salts from the surface and the use of sacrificial plasters. Sacrificial plasters are traditionally used for desalination. Two tests at different sites were performed in order to determine the effectiveness of desalination of different sacrificial plasters. The first test site was a two hundred years old stable wall in Mooste county, Estonia. Salt percentage by mass in the test wall was determined in 2017 and again in 2019. In December 2019 different plasters of local natural clay and lime with additives such as hemp flax, charcoal and turf were tested on the wall. The second test was performed on burnt clay bricks that were placed into salt solution until efflorescence appeared. For desalination process again, different clay and lime based sacrificial plasters were used. After removing the sacrificial plaster, samples from the mortar and bricks were taken to measure the salt content by using Ion chromatography. Clay and hemp flax based sacrificial plasters were the most suitable for desalination and removal.
Sixteen existing multi-family buildings (94 apartments) in Finland and 20 (96 apartments) in Lith... more Sixteen existing multi-family buildings (94 apartments) in Finland and 20 (96 apartments) in Lithuania were investigated prior to their renovation in order to develop and test out a common protocol for the indoor environmental quality (IEQ) assessment, and to assess the potential for improving IEQ along with energy efficiency. Baseline data on buildings, as well as data on temperature (T), relative humidity (RH), carbon dioxide (CO 2), carbon monoxide (CO), particulate matter (PM), nitrogen dioxide (NO 2), formaldehyde, volatile organic compounds (VOCs), radon, and microbial content in settled dust were collected from each apartment. In addition, questionnaire data regarding housing quality and health were collected from the occupants. The results indicated that most measured IEQ parameters were within recommended limits. However, different baselines in each country were observed especially for parameters related to thermal conditions and ventilation. Different baselines were also observed for the respondents' satisfaction with their residence and indoor air quality, as well as their behavior related to indoor environment. In this paper, we present some evidence for the potential in improving IEQ along with energy efficiency in the current building stock, followed by discussion of possible IEQ indicators and development of the assessment protocol.
Existing buildings are a source of great potential for energy efficiency through renovation. In t... more Existing buildings are a source of great potential for energy efficiency through renovation. In this study, the national energy requirements equivalent for the major renovation of existing non-residential buildings using the example of office buildings in five European case countries are drawn out and discussed. The non-residential building sector has been found to be complex and heterogenous with much less available data than for the residential sector, but having greater average specific energy consumption per floor area. The existing non-residential building stock in the studied countries has been divided into varying amounts of groups and sub-groups. The energy requirements have been shifting from the increasing requirements for the U-values of the building envelope (before the 2000s) towards calculated energy demand for buildings as a whole (currently). The requirements for buildings in the near future will be carbon emission based. The energy efficiency of N-RBs in all of the ...
The influence of polymer admixtures upon the characteristics of the C12/15 class concrete
The concrete and reinforced concrete of hydraulic structures are constantly affected by internal ... more The concrete and reinforced concrete of hydraulic structures are constantly affected by internal and external factors. With the rapid improvement of the construction sector chemical materials are being used in concrete more and more often in order that structures should withstand various internal and external factors. The usage of polymer modified concrete as building material is rare due to relatively expensive polymer admixtures. Therefore, sometimes cheaper nontraditional materials (concrete primers), which are made on acrylic base, are used in local building as well. During the research three different polymer admixtures were used to modify C12/15 class concrete. The first admixture (A) was the traditional admixture designed for concrete to improve the strength and longevity. The second (B) and the third (C) admixtures were used as nontraditional. The test results confirmed that better properties had polymer modified concrete which was cured in air. Using professional polymer ad...
Steel fibre-reinforced concrete (SFRC) is widely applied in the construction of civil infrastruct... more Steel fibre-reinforced concrete (SFRC) is widely applied in the construction of civil infrastructure projects, including the following: industrial floors, slabs, walls, and foundations. The application of steel fibres in the reinforcement of concrete remarkably improves the postcracking behaviour of such concrete. In order to estimate this property, the energy involved in absorption is measured by using several valid testing standards: EVS-EN 14651:2005, EVS-EN 14488-5:2006, and ASTM C1550-12a. The objective of this study was to carry out a comparable analysis of the results that have been obtained using previously-mentioned standards and to be able to find a more reliable method for the determination of the fracture toughness of SFRC specimens. Experiments were carried out in accordance with the chosen standards. It was concluded that procedure involved in the ASTM standard provides a smaller variability of results with better levels of repeatability, therefore a smaller volume of ...
Air pressure differences are a key factor in the behavior of building ventilation and air leakage... more Air pressure differences are a key factor in the behavior of building ventilation and air leakages through the building envelope. Field measurements of the air pressure differences over the building envelope were conducted in 24 Finnish municipal service buildings. The measured buildings were mainly schools and daycare centers, of which half were new buildings and half recently retrofitted. All buildings had mechanical ventilation. The measurements were conducted during 2016–2018. The total number of measurement points was 100, and the duration of individual time series varied. According to the results, the mean air pressure difference was within the range of national recommendations (small underpressure indoors) in 81–89% of measurement points, but some cases experienced either strong underpressure or overpressure conditions. In some cases, the air pressure difference showed a clear stepwise constant behavior, while other cases showed larger temporal variation. The conditions varie...
Nowadays there are approximately 500,000 summer cottages in Finland and the amount will increase ... more Nowadays there are approximately 500,000 summer cottages in Finland and the amount will increase in the future. In order to improve the energy efficiency of summer cottages in Finland, the effects of a constant output heating in unoccupied cottages are studied. The idea is to apply a minimum amount of energy in order to avoid moisture-related deterioration of structures and movables. This kind of constant output heating needs an electric input of 5-15 W per floor square meter, which is clearly lower than the energy consumption of conventional heating. Field measurements, which are presented in current paper, aim at indicating the actual moisture conditions in unoccupied Finnish summer cottages. Field measurements in seven non-insulated massive log walled cottages in Tampere region (Finland) have been performed during 2007-2009. Based on indoor and outdoor RH logger measurements (at one-hour interval) the monthly average differences between indoor and outdoor water vapour content were determined. In general, both moisture excess, but mostly moisture deficit was found in summer cottage case buildings during different months a year. The average moisture content of indoor air was found to be lower than the average moisture content of outdoor air indicating an average moisture deficit of indoor air in unoccupied Finnish summer cottages. These results oppose to the usual moisture excess of full-time residential buildings in Finnish climate. Even though the conditions differ, the structures both in summer cottages and in full-time residential buildings are often alike.
The Energy Performance of Buildings Directive (EPBD) of the EU states that Each Member State shal... more The Energy Performance of Buildings Directive (EPBD) of the EU states that Each Member State shall establish a long-term renovation strategy to support the renovation of building stock into a highly energy efficient and decarbonised building stock by 2050. The motive for the study was the dissatisfaction of inhabitants of a single-family building about the heating costs and thermal discomfort. In this study both the emotional and resource efficiency aspects were considered. The structures and technical systems of the studied small dwelling are typical of representing single-family buildings of the Estonian building stock. The initial purpose was to improve the energy efficiency of a building while preserving the existing load bearing structures as much as possible. The research questions were: 1) what the situation before the renovation was, 2) what solutions can be used, 3) making decisions, whether to renovate or demolish. Calculations were carried out – the thermal transmittance ...
When the external appearance of the building is fixed due to heritage requirements the interior t... more When the external appearance of the building is fixed due to heritage requirements the interior thermal insulation is the only possible solution for thermal upgrade of the building envelope. Applying internal insulation to existing buildings is known to pose a challenge in relation to hygrothermal risks, as this can lead to high relative humidity levels, condensation and ultimately, mould growth and decay. The case study building is under historical preservation and therefore this is not allowed to be insulated from outside. The paper describes the hygrothermal assessment of applying internal glass wool insulation and vapour barrier in masonry wall with air gap. In addition to the calculations the condition investigation was also performed. Data loggers measuring temperature and RH were applied during the period of 31.01.2013–16.02.2013. The conclusions were based to theoretical calculations (case study and DIN 4108-3) and practical measurement results based on the data logger value...
In Estonian agricultural buildings there exist a lot of precast concrete load-bearing structures,... more In Estonian agricultural buildings there exist a lot of precast concrete load-bearing structures, which were manufactured in the 1970s and 80s. By now, some of these are rather near for reaching their designed service life. 20 years old prestressed concrete ribbed ceiling panels (type PNS-12) with the dimensions of 6 m (length) by 1.5 m (width) from an existing agricultural building (pigsty) are the subject of current study. The objective of current study was to evaluate the retention stress of prestressing bars (PSBs) of a ribbed panel PNS-12. In other words the purpose was to find out how much of the factory-issued initial prestress was left at the PSBs after 20 years of service. As a novel application in civil engineering strain gauges were applied in the evaluation of retention stress of PSBs in current study. The active strain gauges were glued to the opposite sides of PSBs at the middle-span of the ribbed panel, dummy gauges were glued to the unloaded steel slab. Strain gauges...
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