Different Types Of Roofs Research Articles

Comparative analysis of permeability model construction and risk fields evaluation by roof cutting along the gob in a coal mine.

The productivity of coal mines is seriously threatened by the combined disasters of gas and coal spontaneous combustion, which have become a common disaster mode. It is unclear how the gas and coal spontaneously combusted in the roof cutting along gob working face. The goal of this study is to identify the distinctive features of combined disasters in gob from two different types of roof cutting along working faces. In these two different types of roof cutting along gob working faces, the paper constructs the permeability model of the gob. The findings demonstrate that the data from the field experiment and the simulation results agree, which validates the simulation's reliability. In contrast to single sided roof cutting along gob working faces, double sided roof cutting along gob working faces clearly has a thinner oxidation zone. Moreover, the oxidation zone of the double side roof cutting along gob working faces is closer to the working face, which is located in the shallow area of the gob 50m behind the working face. The gas explosion area and the coal spontaneous combustion area are divided by the double side roof cutting along gob working face, which reduces the risk of compound disasters. Important theoretical direction for the prevention and control of gob disasters in the roof cutting along gob working face is provided by the simulation results.

Modification of the "green" roof using technical solutions to reduce the negative impact of stormwater in urban conditions

The effectiveness and shortcomings of the "green" roof in the management of rainwater in the urban environment are analyzed. The scheme of the construction of a typical "green" roof and its classification in terms of types are shown. The proposal to increase the efficiency of stormwater management with the help of "green" roofs, through their integration with other systems, that is, the creation and implementation of "hybrid green roofs" (Hybrid Green Roofs), is substantiated. The possibility of a "blue" roof as a rainwater management technology without vegetation, which allows for effective retention of rainwater, is analyzed. The design scheme and principle of operation of the "green-blue" roof are given, and a comparative analysis of its effectiveness in stormwater management with traditional and "green" roofs is made. The results of research are presented, which showed that the measured runoff of rainwater from a "blue" roof is about 0.45 dm3/s compared to a regular roof with a runoff volume of 1.55 dm3/s. On the other hand, the runoff from the "green-blue" roof is about 0.1 dm3/s, compared to the control roof (0.3 dm3/s). It is substantiated that a "green-blue" roof is more effective in retaining rain runoff during long-term precipitation than a "blue" roof. However, both options can be applied to urban buildings as effective methods of managing stormwater runoff in urban areas. The scheme of construction and the principle of operation of the "purple" roof is given - as a type of roof that includes a spongy layer of hydrophilic mineral wool, a dense layer of polyester fabric, and can include an additional cellular layer to increase the amount of rainwater that can be retained, thereby reducing peak flow up to 95%. The results of the study are presented, which confirm the technical feasibility of the "purple" roof technology in terms of slowing down the flow and reducing the volume of storm water during rainfall of various intensities. A "Purple" roof, based on the concept of "storage", is conceptually and technically different from a "green" roof and can effectively delay peak rainfall, thereby reducing the pressure on the local stormwater management system. Unlike a "green-blue" roof, a "purple" roof is passive in nature - water flows off without any mechanical drainage points to divert the water. A diagram characterizing the degree of retention of rainwater, depending on the intensity of precipitation, by different types of roofs is presented. The authors proposed a comparative analysis of rainwater runoff management using traditional roofs, "green" roofs, and roofs modified with other "green" roof systems.

Experimental study on traditional timber-concrete hybrid house with different types of roofs using shake table

Buildings with different roofing systems possess different seismic performance during earthquake. Most of the traditional buildings are susceptible to earthquake disaster due to no seismic loading is considered in the design. In addition, irregular buildings have been proven to perform badly during earthquake events. Due to lack of investigations on asymmetrical timber-concrete hybrid building under earthquake loading, a ¼ of this type of building model was tested seismically using a unidirectional shake table. Four structural models with frequencies 3.85 Hz, 3.33 Hz, 2.70 Hz and 2.50 Hz varied using diagonal wooden braces and different roof materials namely heavy metal roof and clay roof tile. The models were subjected to El Centro ground motion excitations scaled to 0.08 g, 0.16 g, 0.24 g and 0.32 g PGA resembling 25%, 50%, 75% and 100% of the actual ground motion strength, respectively. Nine accelerometers and seven LVDTs were used to measure the seismic response of the models during shake table test for acceleration and displacement, respectively. Heavier roof material shows a different trend in the amplitudes across the maximum displacement time history, but a clear decrease in acceleration response for the roof level as compared with lighter roof material.

Research on Roof Cutting Pressure Relief of the Gob-Side Entry Retaining With Roadside Backfilling

Based on the application of the retained gob-side entry in a fully mechanized face E2307 headgate, the stress distribution and deformation characteristics of the roadside backfill body for different types of roof cutting were investigated in this study by employing a combination method of theoretical analysis, numerical simulation, and field measurement. The study uses RocLab software to accurately modify the lithology of the simulation area, discuss the position of roof cutting and the pressure relief parameters of roof cutting, and select the optimal solution of the roof-cutting plan. The results show that the advanced pre-cracking effectively blocks the stress transmission in the high-level roof strata; the roadway is in the stress unloading zone, the stress environment of the surrounding rock in the roadway is significantly optimized, and the deformation of the surrounding rock in the roadway is significantly reduced. In the roof-cutting scheme, the deformation of the surrounding rock in the 90° main roof-cutting scheme is reduced by 78% compared with the uncut roof and by 39% compared with the 90° immediate roof cutting. The research results were successfully applied at the E2307 headgate of the Gaohe coal mine; the maximum roof subsidence and the maximum rib convergence were 121 and 74 mm, respectively. Field monitoring indicates that the deformation of the retained entry was controllable, and the final retaining effects were good.

Influence of microclimate on the effect of green roofs in Southern Brazil – A study coupling outdoor and indoor thermal simulations

A comprehensive understanding of the effect of green roofs on the indoor thermal comfort, under different microclimates, will help to identify key design aspects. In this study, which is the first of its kind in Brazil, the indoor thermal comfort for two different types of roofs, under different microclimates in Porto Alegre in Southern Brazil, have been compared. Coupled simulations using ENVI-met and EnergyPlus linked calculations of outdoor microclimate and indoor thermal comfort. The site was approximately 100 m by 100 m with 24 one-story, naturally ventilated semi-detached houses with an area of 39 m2. One of the houses, located approximately in the middle of the site, represented the building scale. In the original site (with no tree shadings), the substitution of the ceramic by the green roof led to an increase of 9.1% of the time within the thermal comfort zone. This study helps to bridge the current gap between thermal simulations in different scales. Moreover, this investigation concluded that green roofs performed better when in a green environment: for the summer season, with trees partially shading the roof, the green roof resulted in a reduction of the maximum operative temperature by 4.3 °C, whereas for the site without trees, the reduction was 2.8 °C.

Seed point set-based building roof extraction from airborne LiDAR point clouds using a top-down strategy

Building roof extraction from airborne laser scanning point clouds is significant for building modeling. The common method adopts a bottom-up strategy which requires a ground filtering process first, and the subsequent process of region growing based on a single seed point easily causes oversegmentation problem. This paper proposes a novel method to extract roofs. A top-down strategy based on cloth simulation is first used to detect seed point sets with semantic information; then, the roof seed points are extracted instead of a single seed point for region-growing segmentation. The proposed method is validated by three point cloud datasets that contain different types of roof and building footprints. The results show that the top-down strategy directly extracts roof seed point sets, most roofs are extracted by the region-growing algorithm based on the seed point set, and the total errors of roof extraction in the test areas are 0.65%, 1.07%, and 1.45%. The proposed method simplifies the workflow of roof extraction, reduces oversegmentation, and determines roofs in advance based on the semantic seed point set, which suggests a practical solution for rapid roof extraction.

Investigations on the effect of roof types on wave impinging on a building: A hybrid experimental-numerical approach

Numerous efforts have been made to estimate the tsunami wave loads on structures, particularly box-shaped buildings (flat-roofed). As buildings have different types of roofs, insights into their respective wave flow mechanisms are important especially for the overtopping case. This study, therefore, focuses on the effect of roof types on tsunami-like waves impinging on a building. Through a series of wave flume experiments and numerical simulations, wave loads exerted on the front and back faces of a typical gabled-roof building were measured and compared with that of a box-shaped building. Results showed that the roof eaves caused the wave reflection and increased the upstream water depth, leading to an increment in maximum front face force up to 11% relative to the case of flat roof. Howbeit, less wave overtopping effect was demonstrated, thereby inducing a lower wave impact at the back of the building with a gabled roof. A ratio comprising the maximum flow depth and the story height of a building was then proposed, where the effect of gabled roof on the resulting maximum horizontal force was found to be insignificant to a ratio below 0.6. Finally, empirical equations to predict the maximum wave pressure on a building's front and back faces were formulated, which provide practical information for the design of a tsunami-resilient coastal building.

Identification of Roof Surfaces from LiDAR Cloud Points by GIS Tools: A Case Study of Lučenec, Slovakia

The identification of roof surfaces is characterized by a sequence of several processing steps. The boundary detection of different types of roof is realized from light detection and ranging (LiDAR) cloud points and can confirm the real boundary of the roof. In the process of processing LiDAR data, shortcomings have been found regarding the inappropriate classification of points (class 6 “buildings”) concerning the roofs (the points of the building facade were marked as outliers and reclassified). In cases of insufficient point density, there is a problem with not being able to capture either the roof boundary or small roof objects, along with the possible occurrence of gaps inside the roof areas. This study proposes a processing procedure in a geographic information system (GIS) environment that advocates the identification of roof surfaces based on the LiDAR point cloud. We created the contours of a roof surface boundary with a simplified regular shape. From 824 roofs in the studied area, six different types of roof were selected, which this study presents in detail. The expected result of the study is the generation of segments inside the roof boundary. The study also includes the visualization of the outcomes of the spatial analyses of the identified roof surfaces, which forms the basis for determining the potential of solar systems with respect to green roofs for the development of smart city buildings.

Surface runoff as a potential source of pollution

Due to the accelerated development of urbanized areas, the increase of paved and impermeable surfaces, permanent changes in the environment of the city occur. The spatial structure of the city is changing. There are creating significant artificial landscape elements that are not able to absorb rainwater. As a consequence of this unnatural phenomenon in the city was identified a new area pollution source - surface runoff. The formation of surface runoff is affected by several factors. For us, it is important the character of the pollutants in the surface runoff. The paper aims to point out the impact of surface runoff from urbanized areas on the environment. Compare quality parameters of rainwater runoff from different types of paved areas (different types of roof, roadway, car parking). To get acquainted with the legislation covering the area permitted criteria for the content of undesirable substances and the method of their removal.

Integration of Recreational Spaces into Living Buildings Considering Ecological Aspects

The main goal of this article is to explore the modern approaches to solving problems of energy saving and environmental pollution by introduction recreation areas to the residential buildings. Reviewed the popular elements of green building - green roofs and vertical greening in residential buildings. Also, identified the advantages of greened roofs, studied the different types of roofs and various types of plants. The author considered vertical gardening and constructions (such as – suspended systems, modular lattices, metal mesh). The examples of foreign houses using vertical gardening confirm this type of landscaping as a unique. They can create new favorable spaces in an urban environment. So we can conclude that using of green roofs and vertical gardening is very relevant nowadays. They make urban accommodation more comfortable, increase aesthetic conditions of urban environment and they have good effect on human health.

Life Cycle Cost Comparison Study of PV and Concrete Rooftop in Jakarta

This paper presents a comparative study of “life cycle cost” or LCC of a building school rooftop element in Jakarta. The simulation applied two different types of roof: a concrete roof and a PV rooftop. The aim of this study is to investigate the electricity production of the solar panels, the saving to investment ratio or SIR, and the total life cycle cost of each rooftop element. To accommodate those objectives, the calculation utilized a software called “Building Life Cycle Cost (BLCC) version 5” which is a product of the US Department of Energy. The simulation results showed that the LCC can be improved by 27.6%, and the “discounted payback” is reached at year 15. Indeed, this indicates that a roof made of solar panels is promising to replace the existing concrete roof.

Thermal Comfort Modelling Based on House’s Architecture Using Ghost Point Quadratic Explicit Method

When a person builds a house, the different roof shapes become a factor of consideration to obtain the desired model. The shape of a roof is a very influential factor shaping a sense of comfort in the house. Henceforth, everyone will have to sort different forms in choosing the proper roof model that makes them feel comfortable. This research developed a mathematical modeling of the temperature distribution of a room that is influenced by the shape of the roof. This research uses different types of roof to be studied, namely, a rectangular house with a straight, triangular, convex and concave roof. Room temperature distribution is analogous to the concept of thermal fluid dynamics equations. Solution heat equation was solved numerically through explicit finite difference method. However, due to the random observation domain, this study uses ghost-point method. This method uses the quadratic extrapolation approach. The development of mathematical models in the program was compiled using python language, so that the program can represent the temperature of the room at any point well. This research shows that a house which with straight roof is the most efficient in terms of heat distribution

The Establishment of Experimental Green Roofs

The aim of the work was establishment of research green roofs on Mendel University in Brno. The experimental green roofs were established in August 2015 and it is based on current issues of rainwater management and the quality of storm water launched into recipients or sewage system. There is a valid legislation addressing the management of rainwater in environment – decree no. 268/2009, Coll., and decree no. 269/2009, Coll. Four experimental plots were created and placed in Mendel University Campus. It was hypothesized that different types of experimental plots will result in different amount of retained water and in different quality of water runoff. Resulting hypotheses proved statistically significant difference between the height of rainfall and runoff height on individual types of green roofs. In addition, it was shown that the different types of roofs prove statistically significant difference in the ability to reduce runoff (retention efficiency).

SURVEY OF CHANGE IN HUMIDITY, TEMPERATURE AND ILLUMINANCE BY USING DIFFERENT MATERIALS FOR ROOF CONSTRUCTION

A roof is uppermost part of building or shelter which plays a predominant role in protecting inner elements and living things inside structure, this protects against weather, rain, snow, heat, wind and sunlight. The protection properties of roof vary by composites with which the roof is made. In this paper analysis of temperature, humidity and illuminance properties variation due to different types of roofs, the survey made on different roofs such as R.C.C, Asbestos sheets, planks and shack type of roofs for 24 hours are compared to reading that are obtained by open place reading without any roof. This survey clearly represented that readings gradually increases when sun is at his highest point and reduces to zero in the absence of sun. This survey also revealed that using asbestos sheet roof will increases humidity of roof eventually and by using shank roof reduces the temperature, humidity, and lux values passing in to building. Hence this says that although shank roof are less strength roof compared to all roofs these can be used in arid region to reduce interior temperature and humidity, although asbestos sheets are thin layered these can be used in places where humidity and temperature is required compared to temperature and humidity outside the building.

Thermal behavior of alternative materials used as roof and efficiency of the reflective painting on the external face

This study was developed in order to compare the thermal behavior of different types of roofs by measuring the External Surface Temperature (EST) and the Internal Surface Temperature (IST) over the days. The experimental design was completely randomized, with five treatments: AC - Asbestos cement tiles, BA -Bamboo tiles, BAP - Bamboo tiles painted in white, FB -Vegetable fiber tiles and bitumen, FBP -Vegetable fiber tiles and bitumen painted in white, with 15 repetitions, being adopted as repetitions the days of measurement. The temperature of the internal and external roofing surfaces was collected at 8:00 am, 10:00 am, 12:00 pm, 2:00 pm, 4:00 pm and 6:00 pm. Data were analyzed by SISVAR 5.1® program through the analysis of variance and Skott Knott test for comparison of means, significance level at 1%. The FB coverage showed the worst thermal performance compared to other types of coverage, with the best results observed in BAP coverage.

Investigation on the Influence of Abutment Pressure on the Stability of Rock Bolt Reinforced Roof Strata Through Physical and Numerical Modeling

In underground coal mining, high abutment loads caused by the extraction of coal can be a major contributor to many rock mechanic issues. In this paper, a large-scale physical modeling of a 2.6 × 2.0 × 1.0 m entry roof has been conducted to investigate the fundamentals of the fracture mechanics of entry roof strata subjected to high abutment loads. Two different types of roof, massive roof and laminated roof, are considered. Rock bolt system has been taken into consideration. A distinct element analyses based on the physical modeling conditions have been performed, and the results are compared with the physical results. The physical and numerical models suggest that under the condition of high abutment loads, the massive roof and the laminated roof fail in a similar pattern which is characterized as vertical tensile fracturing in the middle of the roof and inclined shear fracturing initiated at the roof and rib intersections and propagated deeper into the roof. Both the massive roof and the laminated roof collapse in a shear sliding mode shortly after shear fractures are observed from the roof surface. It is found that shear sliding is a combination of tensile cracking of intact rock and sliding on bedding planes and cross joints. Shear sliding occurs when the abutment load is much less than the compressive strength of roof.

Influence of green roofs on the seismic response of frame structures

Environmental and operational benefits of green roofs are manifolds; however, their main disadvantages are cost and weight. New technology enabled the use of plastics to reduce the weight of green roof systems to promote their installation. To maximize their potential benefits, green roofs can be installed on existing structures. This study evaluates the influence of green roofs on the seismic response of 3, 6, and 8 storey reinforced concrete ductile moment resisting frames, which were designed according to current seismic standards, however, not designed for green roofs. For each frame, three different types of roofs are considered: gravel flat roof, extensive green roof, and intensive green roof. Nonlinear dynamic time history analysis using an ensemble of twenty real earthquake records was performed to determine the inter-storey drift demand and roof drift demand for each frame. Eigenvalue analysis was also performed to determine the impact of green roofs weight on the elastic and cracked periods of the structure. Results from the analysis demonstrated that intensive and extensive green roofs do not affect the seismic performance of reinforced concrete frame structures.

Hyphomycetes in rain water, melting snow and ice

The investigations performed by direct microscopy method or bait technique (fragments of plants, cellophane, snake skin) using rain water flowing from trees, different types of roofs and melting snow and ice allowed determination of 146 species including 55 new to Poland. Aero-aquatic species were predominant and only several belonged to typically aquatic <i>Hyphomycetes</i>.

Low Cost Roof System For Rural Housing

1.1 Near about 5.6% of the total tribal population of India live in “MEWAR” and “VAGGAR” region of Rajasthan state. In this region, lot of tribals are residing in the out-skirts of Banswara, Udaipur, Pratapgarh and Dungarpur districts. They prefer to live in the jungle with the nature and build their huts by using local material and local skill. It is imperative to introduce the innovative technology of the construction of rural cost-effective huts, which is based on the adoption of the local environment and constructed with the house-hold themselves without the need of the modern tools & equipment. If, we analyze the building costs and its break up, it is observed that the main components of the building are foundation, wall, roof, door & window, flooring and finishing etc. The maximum expenditure for rural houses after construction of walls is in roofs which is 25 % of total expenditure. Therefore, to reduce the cost of the roof of the rural houses this study was under-taken. Necessary sustainable cost-effective techniques are developed for supporting system by use of Bamboo roof trusses and Bamboo spaced column for costeffective rural huts. The average cost break-up of rural hut are shown as below A rural house is a structure providing the suitable place for protecting rural people from heat, cold, rain and wild animals. It can be built with different types of roof covering materials like thatch, tiles, slate, galvanized iron sheets and corrugated asbestos sheets over a supporting structure at present it is a baulk or trunk of a tree and the mud walls. In place of the high cost of supporting structure, bamboo trusses are introduced as the cost-effective system for supporting the roof covering

TESTING ALGORITHMS FOR THE IDENTIFICATION OF ASBESTOS ROOFING BASED ON HYPERSPECTRAL DATA

There are several environmental issues in urban areas that are caused by the unintentional consequences of past activities. One of these issues is the wide application of asbestos cement in roofing materials in the 2 nd half of the 1900s. In this study, our goal was to identify different roof types and to determine those with asbestos components using high-ground (1 m) and spectral (126 bands) resolution airborne hyperspectral imagery (AISA Eagle II) and several classification approaches. In addition, we aimed to identify those wavelengths that play a significant role in distinguishing the different roof types. In the image analysis, the SAM, MLC and SVM classification methods were used to evaluate the different types of roofs. These methods resulted in accurate maps of the roof types, and asbestos cement roofs were identified with over 85% accuracy.