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Achieving carbon neutrality by 2050 requires extensive energy renovation of the existing building stock. In this study we focus on deep renovation with prefabricated insulation elements as a potential solution to attain the required renovation speed and volume. The use of such elements without a proper moisture safety strategy can, however, lead to moisture-related problems, including mould growth. Here we examine the causes of moisture and mould damage in a case study of a building that has been renovated to near-zero energy standards using prefabricated insulation elements. The study elucidates the reasons for the moisture damages detected and proposes two moisture safety strategies to improve the situation. The first strategy emphasizes the importance of ensuring dry construction conditions by either using a full temporary roof or avoiding rainfall during installation. The second strategy addresses localized water damage to the attic floor and involves the use of protective measures, active ventilation and a correct installation sequence. In the case of local moisture damage, the required amount of ventilation air flow during summer is 0.5-0.55 l/(s·m2). During cooler periods, heating is needed. The employed methods include modelling the case-study building with the IDA Indoor Climate and Energy software, as well as mould growth risk assessment based on temperature and relative humidity measurements. The results highlight the effectiveness of both strategies in preventing mould growth if applied correctly, and emphasize the need for thorough planning, moisture safety regulations and rapid response to ensure successful renovation with prefabricated insulation units. The study provides valuable information on moisture safety strategies for serial renovations with prefabricated elements. The existence and proper implementation of a moisture safety strategy is important for achieving the desired energy performance goals while maintaining building durability and occupant health, and it needs to be applied throughout the chain of site management: from the main contractor down to the skilled worker. [ABSTRACT FROM AUTHOR]

Due to their thermal performance, domed roofs are one of the passive solutions that affect energy consumption in buildings. The thermal performance of domed roofs has been investigated in many naturally ventilated spaces. However, few studies have discussed their performance in conditioned spaces. Therefore, this study introduces a computational comparison between domed and flat roofs to investigate their impact on thermal comfort inside a conditioned mosque. At an earlier stage, field measurements were carried out inside a Bahraini mosque to acquire its indoor air conditions during the summer period of 2021, in addition to validating the computational model. The findings of this study confirm that, under mechanical cooling conditions, the flat roof offers a lower indoor temperature than the domed roof by 0.4 °C and 0.1 °C for open and closed doors, respectively. Similarly, the air velocity is lower by approximately 0.01 m/s for both door modes. The overall PMV values of the flat roof are also lower by 0.07 and 0.01, while the PPD values are lower by 0.20, and 0.34 for open and closed doors, respectively. Based on these small differences, it can be concluded that the thermal performance of both roofing systems behaves equally in conditioned spaces. However, the air patterns are substantially different, the overall thermal performance is similar. This similarity drives building designers to rethink the thermal performance of the domed roofs in air-conditioned spaces with such a hot climate, regardless of their aesthetic and acoustical behaviour.

Due to their thermal performance, domed roofs are one of the passive solutions that affect energy consumption in buildings. The thermal performance of domed roofs has been investigated in many naturally ventilated spaces. However, few studies have discussed their performance in conditioned spaces. Therefore, this study introduces a computational comparison between domed and flat roofs to investigate their impact on thermal comfort inside a conditioned mosque. At an earlier stage, field measurements were carried out inside a Bahraini mosque to acquire its indoor air conditions during the summer period of 2021, in addition to validating the computational model. The findings of this study confirm that, under mechanical cooling conditions, the flat roof offers a lower indoor temperature than the domed roof by 0.4 °C and 0.1 °C for open and closed doors, respectively. Similarly, the air velocity is lower by approximately 0.01 m/s for both door modes. The overall PMV values of the flat roof are also lower by 0.07 and 0.01, while the PPD values are lower by 0.20, and 0.34 for open and closed doors, respectively. Based on these small differences, it can be concluded that the thermal performance of both roofing systems behaves equally in conditioned spaces. However, the air patterns are substantially different, the overall thermal performance is similar. This similarity drives building designers to rethink the thermal performance of the domed roofs in air-conditioned spaces with such a hot climate, regardless of their aesthetic and acoustical behaviour. [ABSTRACT FROM AUTHOR]

In the building renovation industry, a growing volume of discarded insulation materials, such as stone wool insulation, prematurely finds its way to landfills or incinerators after building demolitions. However, these materials often did not reach their complete service life potential, and the reuse of insulation materials is usually not considered in current building practices. This study provides a comprehensive overview of the potential challenges associated with repurposing stone wool insulation from existing flat roofs. By means of detailed assessments via dismantling and performance evaluations of collected stone wool insulation boards up to 28 years old, this research reveals the unavoidable damages that occur upon dismantling yet emphasizes that this does not impede reuse. While density and thermal performance remain stable over time, water absorption and mechanical stability are affected. In total, 48% of all short-term tests revealed an increase in water absorption, possibly due to hydrophobic substance degradation. Mechanical performances of aged SW insulation from flat roofs depend on various factors, with 43% and 33% of compression and puncture resistance tests, respectively, not meeting current standards. Beyond a durability assessment, this study advocates for a multidisciplinary approach, uniting materials science, construction engineering, and sustainability insights, to creatively repurpose used insulation materials into future projects. [ABSTRACT FROM AUTHOR]

Copyright of Engineering Mechanics / Gongcheng Lixue is the property of Engineering Mechanics Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Wasteful consumption of electricity in high-rise building in Indonesia is the primary trigger for the increase in carbon emissions. Predominantly, the excessive use of electrical appliances and air conditioning systems is the principal factor contributing to the use of energy within these structures. To effectively address this issue, the importance lies in adopting suitable building envelope material. Therefore, this study aimed to analyze the effectiveness of different insulation types and roof covering in improving the energy-saving performance of office building. There were six proposed renovation for the flat roof of building, consisting of two approaches, namely (1) the incorporation of insulation and (2) the replacement of roof covering layers. Scenarios A1, A2, and A3 have incorporated 100 mm of polyurethane (PU) foam, polyisocyanurate (PI) foam, and fiberglass batt into the design. Meanwhile, Scenarios B1, B2, and B3 opted for ceramic material, Ethylene Propylene Diene Terpolymer (EPDM) membrane, and grass vegetation as roofing material for the existing roof. The results showed that the addition of insulation to roof through Insight 360 and the replacement of roof covering layers produced an energy reduction of 19.5% to 20.2% and 19.5% and 23.5%, respectively. The implementation of green roof in scenario B3 was selected as the most promising renovation option, achieving a remarkable 23.5% reduction in energy consumption.

In the modernist architectural changes of the 19th to the 20th centuries, tuberculosis'therapy influenced the emergence of modernist architectural units, but it has been rarely studied in architectural history. Based on the perspective of tuberculosis, this paper focuses on the history of architectural change from sanatoriums to modernist houses, and specifically analyzes the correspondence and development path between the modernist architectural characteristics -"flat roof, recliner chair, balcony and terrace"and the mainstream treatment of tuberculosis -"Heliotherapy and fresh air treatment". By constructing the picture of the association between tuberculosis and modernism, it argues that tuberculosis is one of the biggest factors influencing modernist architectural change on the one hand, and attempts to explore the medical participation and cultural movement behind the architectural change on the other. [ABSTRACT FROM AUTHOR]

Wasteful consumption of electricity in high-rise building in Indonesia is the primary trigger for the increase in carbon emissions. Predominantly, the excessive use of electrical appliances and air conditioning systems is the principal factor contributing to the use of energy within these structures. To effectively address this issue, the importance lies in adopting suitable building envelope material. Therefore, this study aimed to analyze the effectiveness of different insulation types and roof covering in improving the energy-saving performance of office building. There were six proposed renovation for the flat roof of building, consisting of two approaches, namely (1) the incorporation of insulation and (2) the replacement of roof covering layers. Scenarios A1, A2, and A3 have incorporated 100 mm of polyurethane (PU) foam, polyisocyanurate (PI) foam, and fiberglass batt into the design. Meanwhile, Scenarios B1, B2, and B3 opted for ceramic material, Ethylene Propylene Diene Terpolymer (EPDM) membrane, and grass vegetation as roofing material for the existing roof. The results showed that the addition of insulation to roof through Insight 360 and the replacement of roof covering layers produced an energy reduction of 19.5% to 20.2% and 19.5% and 23.5%, respectively. The implementation of green roof in scenario B3 was selected as the most promising renovation option, achieving a remarkable 23.5% reduction in energy consumption. [ABSTRACT FROM AUTHOR]

Renovation of flat roofs typically involves repairing or replacing the existing roof to improve its performance and extend its lifespan. The renovation process may include a range of tasks depending on the condition of the roof, such as repairing leaks, replacing damaged or deteriorated materials, adding insulation, or upgrading drainage systems. This research aim was to establish the priority of renovation of flat roofs of the public building based on the principles of multi-criteria analysis and fuzzy set theory, using the multi-criteria method PROMETHEE II in fuzzy logic form (F-PROMETHEE II). The proposed approach is adequate due to its ability to transform the uncertain and vague information received from an expert into a fuzzy number. This way, the objective outcome can be obtained, the criteria conflict removed and the alternatives ranking and mutual comparison enabled. It was necessary to analyze the existing literature, the flat roofs of a public building in terms of their current condition, and define the main goals and criteria for the roof renovation project. Based on the defined goals and criteria, the roofs are evaluated and ranked according to the priority for renovation. The planning process of renovation of flat roofs was carried out specifically on the building of the Faculty of Civil Engineering, Architecture and Geodesy in Split. [ABSTRACT FROM AUTHOR]

Wind energy harnessing in built environment contributes to the development of sustainable cities. In this study, flow features and wind energy over roofs with various parapet heights were investigated via computational fluid dynamics simulations. Effects of normalized parapet height (h p / H = 0, 1/320, 1/160, 3/320, and 1/80) and wind angle θ were examined. Moreover, flow features and associated aerodynamic mechanisms were investigated. Effect of h p / H on flow features and wind energy potential depended on roof locations and θ. Parapets had the greatest effect on velocity and turbulence intensity at θ = 45°. At θ = 45°, the largest u occurred at large heights as h p / H increased because parapets would lift up the roof flows. The largest amplification factor of wind energy decreased linearly as h p / H increased from 0 to 1/160, whereas no obvious variations for h p / H were observed from 1/160 to 1/80. The average hub height increased from 1.13 to 1.16 as h p / H increased from 0 to 1/80, indicating potential higher installation cost of wind turbines for larger h p / H. Analysis of parapet height is required to fully assess the wind energy potential and determine the layout of rooftop wind turbines. [ABSTRACT FROM AUTHOR]

An approach of rainwater harvesting (RWH) collected from the roof of a building provides the practical and effective utilization of rainwater which would ensure the availability and sustainable management of water. Instead of flat slabs, architects have designed attic and inverted slabs, which can serve the purpose of rainwater catchments and allow water to fall into dedicated catchment areas. Herein, the approach of rainwater collection through the core-cut method on a flat slab was analyzed on FLOW-3D based on the mean annual rainfall data of Karachi city, Pakistan. The results of the numerical simulation ensured that the developed harvesting system had the capability to capture and deliver the collected water into the storage tank. It has been noticed that between time 0 and 54 seconds, the value of the volume flow rate was 0, which indicated that the rainwater took time to accumulate prior to flowing into the cuts. After t = 54 seconds, a sudden increment in the volume flow rate was observed. This was due to the rainwater that accumulated on the roof and started to go through the cuts. However, after t = 70 seconds, the volume flow rate became steady and very minor fluctuations in the flow rate were noticed. [ABSTRACT FROM AUTHOR]

Interference influence of the spacing and height ratio on the modal generalized force and wind-induced response of the low-rise building roof due to one adjacent high-rise building is investigated at three typical wind directions of 0∘, 90∘ and 180∘, where the low-rise building was, respectively, located at the upstream, side-by-side and downstream of the high-rise building. The mean and standard deviation of the modal generalized force of the first vibration mode mainly exhibits reduction effects and amplification effects, respectively, at the wind direction of 0∘ and 90∘ at small building spacing, and first experiences shielding effects and then becomes amplification effects when the height ratio increases at the wind direction of 180∘. The maximum displacement mainly presents reduction effects at the wind direction of 0∘, the interference factor decreases with the increase of the reduced frequency in engineering range, and the minimum interference factor is close to 0.2. At the wind direction of 90∘, the maximum displacement mainly presents amplification effects, these effects are obvious when the spacing ratio is small and the height ratio is large, and the maximum interference factor is close to 2.2 when the reduced frequency is larger than 0.3. At the wind direction of 180∘, the maximum displacement shows significant amplification effects when the building spacing is small and the height ratio is large, the amplification effects gradually weaken and change into shielding effects as the building spacing increases or the height ratio decreases, and the minimum interference factor is close to 0.3. The minimum displacement experiences amplification effects at all three typical wind directions. [ABSTRACT FROM AUTHOR]

Waterproofing applications in buildings cause environmental impacts due to energy and resource consumption in the production and construction processes of materials. Considering tons of waterproofing materials are applied every year, it is clear that their possible environmental impacts besides physical, chemical, etc. performance characteristics of these materials should also be evaluated. In the article, the production and construction process environmental impacts of the waterproofing systems commonly applied to conventional and inverted flat roofs in Turkey are investigated by life cycle assessment method. The environmental impact analyses of the applications determined for conventional and inverted flat roofs are carried out with SimaPro simulation program, which analyzes life cycle of products and services. According to the results obtained; the total environmental impacts during the production and construction processes are the highest for the mechanically fastened PVC based waterproofing system in conventional flat roof while they are the lowest for the bitumen based liquid waterproofing system in the inverted flat roof. The research results will help architects and engineers preferring waterproofing applications with low environmental impact. Additionally, the paper will also be a guide for future studies where different applications to be carried out in other building subsystems will be investigated environmentally. [ABSTRACT FROM AUTHOR]

The paper presents a multi-objective optimization solution on the basis of ratio analysis and the assessment of the effectiveness of the thermal insulation layer of the flat roof of a class A++ industrial building. The MOORA method was selected for the evaluation of the effectiveness of the middle layer of the thermal insulation material. Five different thermal insulation materials (Paroc ROS 30; EPS100; EPS80N; XPS300; FF-PIR ALK) were assessed according to 4 objectives: the thickness of the thermal insulation layer; the density; the thermal conductivity coefficient; and the price (the third quarter of 2022) of insulation material. Findings of the performed analytical study suggest that the graphite polystyrene foam EPS80N is the most effective thermal insulation material for the flat roof of the nearly zeroenergy industrial building. This material scored the highest number of the relative efficiency points (-0.318). The least effective alternative (from the five tested materials) is the rock wool - Paroc ROS 30 (-0.618 points). The difference between the best and worst alternatives is 51.46 percent. [ABSTRACT FROM AUTHOR]

• The force experiment of flat roof Trough Concentrator model was carried out in the wind tunnel. • The wind load coefficient of the flat roof Trough Concentrator varies with the vertical and horizontal wind azimuth angle. • The resistance coefficient of flat roof is 67.39% smaller than that of ground. • The most unfavorable conditions appear in the tilt angle of 10°, the horizontal wind azimuth angle of 45° and 315°. • The conical vortex at the edge of the roof makes the wind coefficient between the roof and the ground different. In this paper, the flat roof Trough Condenser (FRTC) model is studied using a wind tunnel high frequency dynamic force measurement experiment. The Trough Condenser's (TC) wind (torque) coefficients were obtained in six azimuths. The regularity and features of the wind coefficient when changing within a horizontal wind azimuth angle of 0°~360° and tilt angle of 0°~90° were analyzed. In addition, the TC on the flat roof and the TC installed on the ground were compared and analyzed. The results showed that the FRTC's resistance coefficient, lift coefficient and fundament tilting torque coefficient are all much greater than the side force coefficient, side torque coefficient and azimuth torque coefficient. When designing the TC's structure, the main consideration is the influence of resistance, fundament tilting torque and lift force. The maximal value of the resistance coefficient is 0.938, the maximal fundament tilting torque coefficient is 0.869, and the maximal value of the lift coefficient is −0.620. In addition, compared with the TC on the ground, the roof's resistance coefficient is 67.39% lower, the lift coefficient is 130.65% lower and the fundament tilting torque coefficient is 68.01% lower. Furthermore, as the wind field on the roof is different from that on the ground, while the height of the condenser is lower, and the parapet shields the condenser to a certain extent, the maximum wind (torque) coefficient is also different when under different working conditions. Finally, the effect of the cone vortex on the roof's edge also impacts these results. [ABSTRACT FROM AUTHOR]

In sodium-cooled fast reactors, free liquid surfaces are found in several important components, including reactor vessels; sloshing due to earthquakes is one of the major concerns in design. Especially in cases where seismic isolation systems are installed to prevent or reduce damages to facilities due to earthquakes, periods of vibration are lengthened and become close to natural sloshing periods. As a result, sloshing is more likely to occur. In severe seismic conditions, sloshing waves are considered to even reach a roof slab of a reactor vessel. The structural integrity of roof slabs is required to be evaluated against sloshing impacts. However, there is no widely recognized evaluation method for sloshing impact pressure on flat roofs yet. Therefore, in this paper, a simplified evaluation method is proposed based on Wagner’s theory, which is a well-known classic theory for evaluating impact pressures on rigid wedges dropping on water surfaces. In the proposed method, we assume an equivalent wedge on a flat roof. The impact pressure on the equivalent wedge is evaluated by applying Wagner’s theory. Computational fluid dynamics analysis is conducted to confirm that a key assumption of Wagner’s theory is applicable to the evaluation of sloshing impact on a flat roof. In addition, the predictability of the proposed method is investigated by comparing literature data of sloshing experiments with the estimated values.

Copyright of Online Journal of Art & Design is the property of Online Journal of Art & Design and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Motif Academy Journal of Folklore is the property of Motif Yayincilik and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of International Social Research is the property of Journal of International Social Research and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Abstract In snowy areas, the accurate prediction of snow distributions on roofs plays an important role in designing structures. The process of snow accumulations on roofs is complicated due to the action of wind, which is related to the wind field conditions (e.g. , wind velocity, turbulence intensity, and wind direction), the geometry of roofs, temperature, humidity, and the property of the snow. To systematically study the effect of the length-height ratio of the flat roof and approach flow velocity on the uneven accumulation of snow loads on 3D flat roofs, wind tunnel tests of snow drifting are carried out using silica sand to simulate snow particles. Four models are designed with length-height ratios of 1, 2, 3, and 4, and then four nominal wind velocities are taken into consideration, namely 5.0 m/s, 5.5 m/s, 6.0 m/s, and 6.5 m/s. Two newly added parameters, the snow residual rate η and the erosion rate λ, are set up to illustrate the snow redistribution on 3D flat roofs. Then the effects of wind velocity or roof length on the average transport rate and the mass flux of flat roofs are systematically analyzed. Furthermore, the flow characteristics around the flat roof are obtained by means of numerical simulation, and the relationships between the flow characteristics (vorticity magnitude and friction velocity) near the flat roof and the snow redistribution pattern are carefully discussed. The snow redistribution on flat roofs is obviously uneven due to erosion mainly on both sides where the vorticity magnitude and friction velocity are also larger than in other places. The quantitative analysis indicates that the transport rate of snowdrift on the whole flat roof is proportional to the 4.45 power of the approaching wind velocity, which is slightly larger than the 3.8 derived from the empirical formula from field measurements. Highlights • Tests for snowdrift on 3D flat roofs were carried out in the wind tunnel with high-density silica sand. • The characteristics of snowdrift on different flat roofs were presented, and some parameters were built for describing it. • Some significant factors affecting mass transport rates and mass fluxes on 3D flat roofs were analyzed systematically. • The relationship of flow characteristics near the roof and the snowdrift pattern were carefully discussed. [ABSTRACT FROM AUTHOR]

Wind tunnel simulation is a very important approach to studying snow drifting and predicting drift snow loads on roofs. A complete simulation of the full process of wind-induced snow accumulation on a roof should include snow drifting both during snowfall and after snowfall. However, in most of the previous studies, snow drifting phenomenon was only simulated without concurrence of snowfall. We herein describe simulations of snow drifting on a flat roof during snowfall, which were carried out in a cryogenic wind tunnel using artificial snow particles. Based on the results, we demonstrate the differences and similarities between snow drifting during snowfall and that without concurrent snowfall. The developments of snow transport before saturated state apparently follow the same rule, no matter whether there is concurrent snowfall or not. However, it seems that the required fetch distance for a saturated saltation state can be reduced by snowfall. A formula is proposed to more reasonably describe the development of snow transport rate. Based on test results and deductions, some discussions on similarity requirements for modelling snow drifting on roofs during snowfall will be presented. Finally, a prediction of the prototype fetch distances under different wind and snowfall conditions will also be presented, which can provide a guide for further research and engineering application. • Wind tunnel tests of snow drifting during snowfall are described. • Drifting development during snowfall follows the same rule as that without snowfall. • Snowfall may reduce the required fetch distance for a saturated state of drifting. • Similarity requirements for simulating snowfall are discussed and proposed. [ABSTRACT FROM AUTHOR]

This paper presents an investigation into the characteristics of wind pressure induced by different parts of separation bubbles through the wind tunnel test on a large-span flat roof. Production mechanism of wind pressure characterestics at each part of the flat roof was analyzed in terms of the flow motion inside and outside the seperation bubbles. The distribution of mean and fluctuating pressure coefficients was firstly presented, followed by an analysis of the correlations of longitudinal and transverse pressure fluctuations. The wind fluctuating pressure spectra and phase angles were then presented for longitudinal taps. Lastly, the characteristics of wind pressure induced by separation bubbles were discussed. The test results show that at the forepart of separation bubbles, significant correlation of longitudinal wind pressure and low-frequency wind fluctuations are observed. The statistical peak suction is detected at a distance of 0.2 times reattachment length from the separation point. At the central part, the maximum fluctuating wind pressure occurs at approximately the midpoint of the reattachment length, which is the transition point for the wind fluctuation from low-speed propagation to high-speed propagation. The upstream and downstream wind fluctuations of the transition point are found to be negatively correlated and out of phase. At the reattachment region, the correlation in the transverse direction is weakened by high-frequency wind fluctuations. The minimum peak factor occurs at the reattachment point [ABSTRACT FROM AUTHOR]

Through wind tunnel tests of rigid model, the wind pressure characteristics of flat roofs with rounded leading edge in different wind directions were investigated, focusing on separation bubble and conical vortices. The wind pressure distribution and area-averaged pressures near the corner of flat roofs with and without rounded edge were compared and analyzed. The eigenvalues and eigenvectors of wind pressure field were given by proper orthogonal decomposition. Characterestics of wind pressures located at the rounded leading edge were discussed over the time and frequency domain. The results indicate that with rounded leading edge, the pressures induced by separation bubble and conical vortices attenuate monotonically, although the pressure may increase near the leading edge. The mean area-averaged pressure near the corner can be increased for the rounded leading edge under the effect of separation bubble. When exposing to conical vortices, the mean and peak of area-averaged pressures near the corner are decreased by up to 68% and 82%, respectively. The involved area and energy of wind pressure fluctuation decrease towards the rounded leading edge, where the most evident decrease occurs on the surface of the flat roof with rounded leading edge of relatively larger radius under conical vortices. At the rounded leading edge, the maximum suctions and spectral peak of pressure fluctuations may exceed those of the adjacent region. As the radius of the leading edge increases, the maximum suctions and low-frequency spectral peak of pressure fluctuations decrease. [ABSTRACT FROM AUTHOR]

New edition of the German National Annex to Eurocode 1, Part 1‐3 „Snow loads" in 2019‐04 The new edition of the German National Annex to Eurocode 1, Part 1‐3 „Snow loads" considers the user experiences and code interpretations, as well as simplifications of shape coefficients for the current snow load specifications. In this contribution, the background and the essential changes between the 2019 edition of DIN EN 1991‐1‐3/NA:2019‐04 and the 2010 edition are explained in detail. The new regulations include, for example, the concretisation of snow loads on extended flat roof areas, the regulation of snow loads on flat inclined roofs between tilt‐mounted photovoltaics or solar systems as well as an informative annex for ice loads. [ABSTRACT FROM AUTHOR]

Domed roofs are the masterwork of mechanical engineering because of building heat load reduction in Iran. Received ‎solar radiation on a domed and flat roof has been compared with each other experimentally and numerically in this ‎research. Data measurements have been done on 15th day of each month from sunrise to sunset with one hour intervals. ‎A 1/10 scaled model of a mosque in Yazd has been used for experimental investigation. Data obtained on 13 point on ‎this model. The dome has three circuits named A, B and C, with a horizontal angle of 30o, 50o and 90o respectively. ‎Four points on every circuit in the four main directions are considered. Results show that the total received solar ‎radiation (per unite area of dome base) for flat roof is higher than domed roof. The maximum solar radiation received ‎on the East and South direction for warm and cold seasons respectively for domed roof. The minimum solar radiation ‎received on the North direction during a year. The maximum solar radiation on the East direction is received in the ‎early morning, while the West has its maximum in the late afternoon. In addition the maximum received solar ‎radiation for the flat roof and the South direction of the dome occur at approximately noon, while the maximum ‎received solar radiation tends to be happened before noon for the North direction.‎

The failures of solar array systems occur occasionally under strong or extreme winds. The wind load is one of the main loadings on such systems. To investigate the characteristics of wind loads of solar arrays mounted on flat roofs with deflectors and those on gable roofs, pressure measurement tests on rigid models were conducted. The wind pressures on the upper and lower surfaces of solar panels and also the net pressures for these two types of roofs were examined. The variations of the largest negative peak net pressures with the tributary areas, considering all wind directions, were obtained and compared with the provisions on the wind design of flat-roof-mounted solar arrays by the Structural Engineers Association of California (SEAOC) as well as the recommended net pressure-effective area curves proposed by previous studies. The results indicate that the largest negative peak net pressures of solar arrays mounted on flat roofs are larger, and decrease more rapidly with the tributary area than those on gable roofs. The results of flat roof ones agree well with the SEAOC provisions. The design wind loads proposed by previous studies are conservative when the tributary area is relatively large. [ABSTRACT FROM AUTHOR]

Based on the wind tunnel experiment of the large-span flat roof and saddle roof, the area time history method was adopted to get the most unfavorable shape factors, and the calculation results were analyzed according to the CB 50009—2012 ‘Load code for the design of building structures’. The Davenport crest factor method and the Hermit model theory were used to calculate the Gaussian and non-Gaussian peak factors respectively, and the most unfavorable peak wind pressure on the roof surface was obtained. Results show that the shape factors of the GB 50009—2012 on the cladding and components are not reasonable and the design wind loads of the front windward corner area is underestimated obviously. For the front windward central area, the shape factor is conservative; for the central area of the roof, a single coefficient is used to underestimate the shape factors at the junction of the windward comer and the central area. Therefore, based on the wind tunnel test and theoretical calculation results and also reference to the AIJ-2004 loading code, the most unfavorable shape factors and peak suction are defined by partition and the suggested values are also given. [ABSTRACT FROM AUTHOR]