Climate Load Research Articles

Predicted corrosion rate on outdoor exposed concrete structures

PurposeA significant part of Finnish concrete building stock is relatively young. Thus methods to adopt the existing building stock to climate change are needed. To plan and correctly timing the service actions there is a need to study the rates of different deterioration mechanisms. The reinforcement corrosion in Finnish outdoor exposed concrete structures is almost solely carbonation-induced corrosion. In former studies, it has been shown that active corrosion phase can also have a major effect on the total service life of the structure. The paper aims to discuss these issues.Design/methodology/approachIn this study, the effect of climate change on predicted corrosion rate of concrete reinforcement in projected 2050 and 2100 climates compared to present climate were studied to consider adaptation methods for the climate change. The calculations are based on a corrosion propagation model, which takes into account four different climatic factors: wind-driven rain, temperature, relative humidity and solar radiation.FindingsA significantly higher corrosion rates and thus faster corrosion-induced damage can be expected in the future climate. The increase in corrosion rate is the highest in the late autumn and winter because of the increasing amount of precipitation and weaker conditions for concrete structures to dry. In addition, the duration of high corrosion rate periods is increasing which may shorten the propagation phase. However, corrosion rate is highly dependent on the direction of the greatest climate load and the grade of sheltering which can be taken into account in service life calculations and while planning service actions.Research limitations/implicationsThere are different sources of error because of the uncertainties with both the used model and the climate change scenarios. That is why the results are discussed in more general way than comparing the actual numbers with each other.Originality/valueThe propagation model used in this study has not been used before in adaptation studies. The climate change effect on carbonation-induced corrosion has also been limited while the studies have focused on chloride-induced corrosion.

Operational Safety of Skeleton Frame Built Structures with a Low-Rigidity Covering

The paper discusses issues related to the safety of light skeleton frame structures with a low-rigidity covering. Non-building structures of this kind have been broadly used as large-scale greenhouses. The most commonly used layout for these structures is the multi-span layout. The paper presents legal preconditions related to construction and operation of these structures; it particularly focuses on external climatic loads, i.e. snow and wind, affecting reliability of these structures due to their uneven distribution on multi-slope roofs. One of the problems associated with the use of plastic covering is the accumulation of snow in multi-slope roof valleys. Designers sometimes happen to transfer this problem to the user of the structure by allowing obligatory snow removal in their calculations and thereby leading to situations where the snow load of the main structural frame is underestimated. The paper presents examples of structures in case of which, as a consequence of underestimating the snow load, failures can occur. In addition, a method of determining wind loads for roof shapes not provided for in standards was noted. The summary contains final conclusions regarding construction and operation of foil tunnels in Polish conditions of operation.

The Method of Prediction Climatic Loads on the Building Enclosures

Based on the numerical solution of the differential equation that determines one-dimensional heat transfer under unstable conditions with constant coefficients, a method was developed to calculate the temperature distribution over the cross section of the enclosing structure. Based on the developed method, a method of determining the number of cycles of freezing and thawing of moisture in the cross sections of the outer wall of the building was calculated. This method was tested in the experiment on the exterior walls of operating buildings. The results showed good convergence of the real and calculated temperature values. The calculation of the number of cycles of freezing and thawing on the cross section of the outer wall of the building according to the developed methodology and the experiment showed the same results. The method of numerical assessment was developed to show the impact of global climate change on enclosed structures. The parameter of temperature load of enclosing structures was introduce. The method uses meteorological data of outdoor air temperature over the last 50 years and the results of calculation of temperature fluctuation of the enclosed structures. The use of this method allowed to calculate the number of cycles of freezing and thawing in cross sections of the outer wall at any given time period, and, therefore, more accurately predict the durability of enclosed structures. In addition, the developed technique allows quantitative comparison of different designs of external structures on the thermal load, taking into account global climate change.

ВПЛИВ ЯКОСТІ ОЧИСТКИ МАСЛА НА МОТОРЕСУРС ДИЗЕЛЬНИХ ДВИГУНІВ АВТОМОБІЛЬНОГО ТРАНСПОРТУ

The methods of upgrading of motor oils which determine of engines exploited in different climatic terms and loading modes are described in the article.

Hygro-mechanical investigations of clavichord replica at cyclic climate load: Experiments and simulations

Abstract A long-term experiment on the load bearing structure of two identical replica of a clavichord from 1807 is carried out. One clavichord is stored in a showcase with nearly constant exhibition room climate. The other one is stored in a climate chamber and loaded by a weekly changing climate of about 30% and 80% relative humidity. By photogrammetric methods, the instruments’ displacements are measured every week over a period of two years. Within a numerical study, the first humidity cycles are simulated by the finite element method applying multi- Fick ian hygro-mechanical material models with respect to short-term response and without viscous phenomena for the first instance.

Influence of Pressure Equalisation Elements on the Quality of Insulating Glass Units

Abstract Continuous increase of expectations concerning improvement in quality of building partitions by means of increasing their thermal insulation properties brings, among others, a need of modification in standards that have been applied to the double glazed windows so far. Triple-glazed and quadruple-glazed IGUs are used more and more often. Such elements have better thermal properties, but they are more prone to deflection and stress resulting from climatic load, i.e. changes in temperature, atmospheric pressure and wind load. Due to the above certain concepts occurred that consist in equalising gas pressure in the gas-filled gaps with the atmospheric pressure. The article contains assessment of such solutions in the context of providing suitable technical parameters of glass panes: thermal insulation and susceptibility to climatic load. It was stated that the pressure-equalizing elements (capillaries) can result in a significant reduction in the quality of the glass partition in the event of the argon purging chamber or damage to the low-E emissions. The lower risk of using required thermal properties occurs when periodically active valves are used, they operate only in case of extreme pressure level differences. Further analysis concerned the idea of pressure equalisation between the gaps of a triple-glazed unit, as that can be done by using an edge spacer of appropriate design. On the basis of comparative analysis of static values it was shown that it is a reasonable solution. Such a unit maintains the properties of a tight unit, while the possibility of gas exchange between the gaps leads to relief of the central glass pane in the unit, thus allowing for decreasing its thickness to 2 mm.

Performance of hydrophobized historic solid masonry – Experimental approach

The hygrothermal conditions in historic solid masonry are expected to change for the worse, with the application of internal insulation. Nevertheless, internal insulation plays a role in a holistic energy retrofit of historic buildings. With careful considerations and correct application, hydrophobic treatment may help remedy moisture ingress from external rain loads. This study includes experimental investigations of the effect on hygrothermal performance of various hydrophobization treatments on both brick and air lime mortar. An investigation of water migration through masonry applied with imitated climatic loads is also reported. The study showed a larger efficiency of hydrophobization on specimens of brick compared to the efficiency of hydrophobization of specimens of air lime mortar, which may be problematic in cases where mortar joints are the primary means for water ingress. Silane-based treatments generally proved to be most efficient in brick, whereas a variety of other active components were most successful in air lime mortar treatment. The investigation of water migration showed a distinct effect of silane, cream hydrophobization, though most evident in the external part of the brick.

Introducing a stress-dependent fractional nonlinear viscoelastic model for modified asphalt binders

Asphalt binders generally behave in a linear viscoelastic manner under conventional stress and strain level. There are several researches and technical protocols consistent with linear viscoelastic theorem. However, two main reasons can affect this well-known behavior of asphalt binders: 1) modification of asphalt binder with some additives causing a change in its microstructure and 2) higher order stress and strain level induced to asphalt binder under heavy traffic or climate loading. It is important to consider non-linear viscoelastic behavior of asphalt binder and its effect on conventional characteristics of asphalt especially two constitutive functions of creep compliance and relaxation modulus. In this research, nonlinear viscoelastic properties of asphalt binders modified with crumb rubber, styrene-butadiene-styrene and polyphosphoric acid are investigated to evaluate the variation in non-linear viscoelastic parameters due to addition of these modifiers. For this purpose, a specified research program was defined to consider non-linear behavior of one neat asphalt binder as well as nine modified ones. Based on a robust literature review and some prior experiences, three different extents selected for each modifier and then specimens were made. Implementing a simple creep-recovery test with creep loading time of 1 s and 100 s and 999 s unloading to simulate traffic load by using a dynamic shear rheometer at different stress levels of 0.1, 1, 10, 20 and 30 kPa, non-linear viscoelastic behavior of neat and modified asphalt binder was captured. The generalized fractional nonlinear viscoelastic model is introduced and successfully implemented to simulate creep and recovery behavior of neat and modified asphalt binders. Addition of all modifiers to the neat asphalt binder alters its non-linear viscoelastic behavior and properties. For short time creep loading, crumb rubber and polyphosphoric acid amplify non-linear behavior while SBS control it and for long creep loading time all asphalt modifiers increases non-linearity of asphalt binder’s viscoelastic behavior.

RATIONAL ALTITUDE STRUCTURE FOR PLACING THE WIND EQUIPMENT IN THE CONDITIONS OF UKRAINE

Purpose. For wind observations special wind equipment is used, which should be placed at a certain height above the ground for a relatively short period of time. Such equipment can be transferred from one region to ano-ther. Therefore, the main purpose of the studies outlined in the publication is the selection and justification of the construction of a mobile altitude structure for the placement of wind equipment in the natural and climatic conditions of Ukraine. Methodology. To achieve this purpose, first we chose the type of altitude structure from the existing ones. Next, we determined the nature of the effect of natural and climatic loads on these structures in accordance with the norms of Ukraine. After this, we performed a numerical analysis of the work of altitude structures by the finite element method on the basis of the Lira software. Also, an economic evaluation of the expediency of using altitude structures of a certain type was made, taking into account the lease of the land plot for their location. Findings. According to the results of the conducted studies, it should be noted that for the conditions of Ukraine a steel tower is the most rational mobile altitude structure for placing wind equipment for a relatively small interval of time. In comparison with a steel mast of a similar height, the total cost of its installation and operation is lower. The X-cross brace for steel towers from 50 to 60 m in height is more rational than the K-brace. Herewith, its usage decreases the construction cost almost by half. Taking into account the possibility of transportation, the separation of the steel tower into assembly units of 8-10 m in length is the most effective. Originality. The authors proposed the method for estimating the economic efficiency of choosing a mobile altitude structure depending on the natural and climatic conditions of the terrain. In accordance with this method, the most rational type of altitude structure is determined taking into account its mobility. Practical value. Application of the proposed approaches and the solutions allows reducing the time required for calculations in design practice and also more reasonably approaching the choice of design solutions for altitude structures.

The snow load in Europe and the climate change

It is often assumed that, as a consequence of global warming, a reduction of snow load on the ground should be expected. In reality, snow load is often depending on local orographic situations that can determine an increase of its height, even when the average snow height over the surrounding areas is reduced. Large snow loads on roofs during the winter season of 2005–2006 led to over 200 roof collapses in Central Europe. To proceed with the adaptation of the European standards for important buildings and infrastructures to the implications of climate change, the expected changes in the climatic loading shall be assessed in terms of the Eurocodes concept for characteristic values of variable climatic actions. The paper presents a procedure for derivation of snow load on ground from data on daily temperatures and precipitation. In addition, it allows to derive the characteristic snow loads from climate change projections and thus to evaluate the future trends in variation of snow loading. Analysis of these trends for the Italian territory is performed by comparing the results for several subsequent time periods of thirty years, with those obtained for the reference period 1951–1980. Results presented show a significant increase in the snow loading for the period 1981–2010 in many regions in north and east Italy in comparison with the reference period. It is suggested that a European project on snow load map shall be started, in order to help National Competent Authorities to redraft the national snow load maps for design with the Eurocodes.

Thermal Balance in the Process of Fresh Water Production from Atmospheric Air Using the Sea Waves Renewable Energy

Climatic changes and man-induced environmental load cause to a shortage of drinking quality fresh water. Upon that, fresh water sufficiency is one of the preconditions for quality assurance in adequate living standards as well as for domestic and foreign political stability especially in developing countries. A lot of technologies of fresh drinking water production are known today. Most of them involve significant power consumption and endanger to environment. As a rule these technologies use non-renewable hydrocarbons as power source. The author-developed technology of fresh drinking water obtaining from atmospheric air involves the use of clean renewable energy of the sea. This article bases the method of water production from the air. It is also describes technology implementation energy balance.

Modelling of Railway Track Temperature Regime with Real Heat-Technical Values for Different Climatic Characteristics

AbstractHigh quality of railway track construction is a major priority. One of the quality elements is the resistance to load of railway formation with individual structural layers caused by negative temperatures during the critical freezing period of winter. Numerical modelling allows obtaining more control outputs at different climatic loads. The presented paper shows the load of railway track model with different variants of climate and shows the importance in the designing of the non-transport load under negative temperatures, i.e. observation of transition of the zero isotherm through the layers of railway subgrade. If the subgrade layers of the railway formation are built with high quality and durability then the axis of the track will keep its geometric spatial position during the long-time operation.

Performance Analysis of the Joint Sealing Materials for the Cement Concrete Pavements in Civil Airports

Cement concrete pavements in airfields need to be sealed with all kinds of sealants to prevent the ingress of water or incompressible materials into their joints. Airfield cement concrete pavements have unique in-service conditions, and the sealants in these environments are not only exposed to climatic effects and heavy traffic loads but also to jet fuel and fluids. By analyzing the causes of damage and selecting four types of typical joint sealing materials for cement concrete pavements in civil airports (e.g., silicone, polyurethane, polysulfide, and polythiourethane), the basic physical properties, adhesion, and resistance of these materials are tested. By combining the experimental results with the relevant technical specifications and standards at home and abroad, these materials are divided into high elastic modulus and low elastic modulus based on 23℃ tensile modulus. The surface drying time, cone penetration, elastic recovery rate, tensile modulus, low temperature tensile elongation, tensile bond, fuel immersion characteristics, resistance to heat ageing, and flame resistant properties of these materials are used as performance indices and provide a technical reference for the construction of airport cement concrete pavements.

Conversion of a Temporary Tent with Steel Frame into a Permanent Warehouse

The paper is dealing with the problem of a functional conversion (involving both architectural and structural issues) applied to the case of an industrial building. As well known, temporary tents, designed according to the European Code EN13782, represent a remarkable stake on the building market and a fast and practical solution for some situations. It is exactly the case approached by the paper, where the investor has initially decided to erect on his platform a provisional shelter for agricultural machines and subsequent staff, built of a light steel structure covered by PVC roofing and cladding. This temporary tent has been acquired from a specialized supplier in form of a series product. After using the tent for a number of years, the investor has decided to convert the existing structure from architectural and structural point of view by switching to a permanent structure designed accordingly. Important changes were thus imposed both to the architectural part (technological flows, openings, facades) and especially to the structural part where this switch imposed a re-design to the codes of permanent structures (especially as far as climatic loadings are concerned). The required architectural change implied the building of a 70 cm high concrete plinth and replacing the PVC membrane temporary roofing and cladding by permanent 60 mm thick PUR sandwich panels. Together with a new system of openings this has led to renewed facades of the buildings. As for the structural change, the required conversion has imposed a thorough checking of the existing steel structure (very slender and typical to a tent) in view of transforming it into a permanent structure. The consolidation measures of the existing galvanized steel structure are described, together with the measures applied at infrastructure level in order to implement the required conversion.

Increased thermal induced climatic load in insulated glass units

Increased thermal induced climatic load in insulated glass units

High-resolution spectral mapping of urban thermal properties with Unmanned Aerial Vehicles

The integration of microclimatic information and physical properties of the materials into urban design is essential for adequately addressing the challenges related to climate change and to adaptation of urban environment to new climatic loads. Especially, the thermal and optical properties of materials used in the urban fabric play a fundamental role in determining the microclimate and building's energy balance. The present research approach aims at analyzing the thermal characteristics of the materials and the surface temperature distribution using airborne multispectral imaging sensors mounted on Unmanned Aerial Vehicle (UAV). Aerial surveys and in-situ measurements have been carried out in April 2016 at the Municipality of Ymittos in Athens (Greece). The applied multi-sensory survey included high resolution imaging of the materials in the visible and near infrared (VIS/NIR) wavelength region and IR part of the spectrum. The images have been analysed to form maps of surface temperature distribution and of material properties. The derived thermal maps show the changes in surface temperatures of the urban materials during a diurnal heating cycle. In addition, ground measurements of VIS/NIR reflection and albedo from the survey area were obtained and an albedo map and a map of apparent thermal inertia were derived. Thermal scanning of the asphalt in the area, allowed the estimation of the state of decay due to weathering and traffic. The combined maps of surface temperature, albedo and apparent thermal inertia give new perspectives of the urban features and enhance the classification of fine urban material and the energy balance models.

Structure of volcanic landscape in the equatorial belt (A case study of the Kerinci Volcano, Sumatra Island)

An analysis is made of the volcanic landscape structure of Mount Kerinci, the highest volcano in South-East Asia. Field observations, remote sensing methods, and also cartographic material were used in obtaining new evidence to gain a more penetrating insight into the characteristics of structure and altitudinal zonation of the landscapes along the equatorial belt that have shaped themselves and are evolving in conditions of intense volcanic activity, equatorial climate and heavy anthropogenic load. The analysis revealed natural and anthropogenic landscape-forming factors that determined the present-day landscape appearance of the Kerinci volcano. Within the boundaries of the volcanic structure, landscapes of the mountain class show the highest diversity of landscape taxa. They are represented largely by slope units. With an increase in altitude, there is an increase in the proportion of landscapes of steep and vertical slopes as well as moderately steep slopes, along with the disappearance of landscapes of smart slopes and valley bottoms. A less diverse landscape structure is characteristic for subclasses of aggraded-denudation plains where there occur only landscapes with bogs and waterlogged meadows predominating. Anthropogenic modifications of landscapes occur mostly within subclasses of smart slopes and aggraded-denudation plains. They are characterized by a predominance of agricultural plants.

Aerial Survey and In-situ Measurements of Materials and Vegetation in the Urban Fabric

The integration of microclimatic information and energy balance of the materials into urban design is essential for adequately addressing the challenges related to climate change and to adaptation of urban environment to new climatic loads. Several studies model the urban climate from multispectral satellite measurements. However, the remotely sensed measurements usually have a spatial resolution of several meters and are not suitable for determining microclimate effects in urban areas and on individual buildings. Moreover, they require consideration of the intervening atmosphere and the surface radiative properties that influence the emission and reflection of radiation within. The present research approach includes in-situ measurements and aerial surveys with VIS/NIR multispectral camera and IR camera mounted on a UAV. Analysis presented here, aims (1) to identify physical characterization of reflectance properties in a variety of urban settings in Athens, (2) to explore the response of vegetation, cool and conventional materials in the NIR region (3) to study climate parameters essential to the bio-climatic design in this urban cover (4) to elaborate observational studies for obtaining better validation of the surface effective parameters derived. The sensors on UAVs provide a unique perspective of urban features for revealing the complex mechanisms that lead to micro-climatic modifications and to quantify their relative contribution. The application of NIR images in building and urban scale analysis is innovative and reveals different properties of the surface of the objects.

Фауногенетическая структура орнитонаселения и ее трансформация в связи с депрессивными изменениями гидрологического годового цикла в среднем течении р. Медведицы

The flood plain of the Medveditsa River in the middle current is characterised by various fauna of birds. Nowadays significant transformations of local fauna, influenced by climatic conditions and anthropogenous loadings, are observed. In the valley of the river the most significant factor influencing communities of birds is the flood mode. The purpose of the work is the birds faunogenetic structure analysis of the Mededitsa river flood plain, and also it`s dynamics under the conditions of degradation of an inundated hydrological cycle. Collecting field data was carried out on the territory of the Medveditsa River valley between the Uritsky village (55.43 ° EL of 44.93 °N) and Atayevka village (51.17 ° EL 44.50 °N) of Lysogorsky district of the Saratov region in May-July, 2013–2016. The methods of research included the birds quantitative accounting, mapping of nesting sites, selection the faunogenetic complexes, determination of the birds residence status in habitats. Assessment of statistical similarity of species quantity in various ecological groups of birds under the conditions of the changing water content of a flood plain was carried out by means of Mann-Whitney nonparametric U-criterion. During the observations period the manifolding of 117 bird species which are falling into nine faunogenetic complexes was confirmed. According to their ecological adaptations birds fall into dendrofila, limnofila, sklerofila, types of open spaces, evritopa and sinantropa. The species having relationship with the European broad-leaved woods, Palearktik's woods, as well as widespread azonal palearkta, prevail among them. Representatives shares of the Mediterranean, Manchurian, steppe and desert and taiga fauna are small. The Arctic and hypoarctic birds meet in the Medveditsa River valley during seasonal migrations. Degradation tendency of the annual Medveditsa River hydrological cycle was identified: a frequency of anomalously low floods is ascending and abundantly high waters occur once in seven-ten years. As a result, we observe Essential structural change of habitats the limnophilic of the birds dated for reservoirs of the central flood plain and a priterrasye. The analysis of the U-criterion calculated by quantity of the nesting in different years limnofila, dendrofila types and birds of open spaces, showed that water content of a flood plain does not influence significantly the structure of birds communities (U emp > U0.05). We identified a certain difference (U emp< U0.01) in quantity of breeding individuals of the limnofila birds in the years with the maximum and minimum levels of the priterrasny Lebyazje lake on the model platform.

Autonomous power supply using solar energy in Russian Far East regions

The most useful application of PV solar power in Russia are autonomous power systems in regions with high costs of organic fuels (due to transportation problems). Effective application of PV power needs comprehensive data analysis for solar energy resources, electric and heat load graphs and fuel costs. This paper is devoted to climate and power load data analysis for Russian Far East regions (in connection with PV application) and PV-based power plant mathematical modeling for several locations.