Concrete Roof Tiles Research Articles

An Investigation on Indoor Temperature of Modern Double Storey House with Adapted Common Passive Design Strategies of Malay Traditional House

Past years have witnessed the popularity of traditional Malay house as a common housing type in Malaysia. However, double-storey house has become one of the common types of low-rise housing in Malaysia. Several passive cooling strategies have been adopted to cope with the hot-humid climate of Malaysia. In this study, the thermal comfort of a double-storey house was examined when different passive cooling strategies that were adopted from traditional Malay houses were applied using IES-VE 2019 building simulation software. The simulation was conducted for various design strategies such as changing concrete roof tiles to clay roof tiles, adding two small openings to the attic, removing the ceiling between the upper floor and the attic, and extending the overhang by 50% of its length for all the four facades. All these strategies were tested and compared between full-day natural ventilation and without any ventilation. The thermal comfort of these strategies was graphically defined based on the operative temperature. These analyses revealed that protecting the building envelope by extending the overhang by 50% of its length for all the four facades could ensure the best thermal comfort is achieved compared to other selected strategies. Recommendations for further studies are also outlined in this paper.

Study on the feasibility of using iron ore tailing (iot) on technological properties of concrete roof tiles

The mining industry produces large amounts of waste during the iron ore processing. This material is usually discarded into tailing dams, posing high maintenance and monitoring costs as well as causing serious environmental disruptions, such as air contamination and leaching of substances. The reuse of such waste as alternative materials in the construction industry is an alternative to its disposal. Therefore, this study aimed at evaluating the effect of using iron ore tailing (IOT) on the physical, mechanical, thermal and durability properties of concrete roof tiles obtained by the extrusion process. The base trace in mass consisted of 1 : 3 : 0.56 (cement : medium grade natural sand : limestone powder). The treatments were based on 25, 50, 75, and 100% mass replacement of limestone powder by iron ore tailing. After shaping, the concrete roof tiles were taken to a saturated humidity chamber at room temperature for 28 days. Concrete roof tiles were evaluated for water absorption, dry weight, transverse breaking strength, bulk density, apparent porosity properties and microstructure at 28 curing days and after accelerated aging. Thermal conductivity, wettability, XRD, permeability and impact resistance analyses of roof tiles were also performed. There were significant transverse breaking strength and porosity values improvements as a result of using greater amount of IOT compared to traditional concrete roof tiles. The technological properties were improved by increasing the amount of waste, meeting international marketing standards. The use of iron ore tailing as total LP replacement showed great potential for use as raw material for concrete roof tiles production, allowing the correct disposal and development of new, more sustainable products, as well as the improvement of roof tiles physical and mechanical properties.

A REVIEW ON COOLING ROOF TILE MATERIALS

In Indian buildings concrete roof tiles are mostly used. Commonly in traditional rural residential buildings. The cooling roof tile technology provides less heat absorbs and sunlight reflecting comparing to standard roof tile. Just providing light color can reduce the heat gain in hot climate, same principal is used in cooling roof tile material. Considering the essential function of roofing features in building energy efficiency and interior thermal quality conditions, novel approaches to enhance the thermal energy output of this diffused roofing feature have become a main development issue. In this opinion, cool roofing technologies are an important approach to this goal. The current research deals with the Review of revolutionary materials or coatings for conventional roof tiles, with the goal of growing their cooling capacity.

Influence of rice husk ash (RHA) on performance of green concrete roof tile in application of green building

This paper studies on the development of green concrete roof tiles by using rice husk ash (RHA) as a partial replacement of cement as a green material. Rice husk is a product of agricultural waste that can be found easily and in large quantities due to increased annual paddy production in Malaysia. Demand for cement in construction has increased over the years as a result of over dependence on the modern building materials, which are so expensive that low income earners cannot afford building houses of their own. Besides, the satisfaction of building users is closely related to thermal comfort which is a complex dynamics of temperature and humidity. In this study, cement was replaced by the RHA at 0% until 20% by weight. Roof tiles performance were assessed based on Malaysian Standard (MS) requirement comprised of transverse strength, water absorption and water permeability. Results show that up to 10% of RHA give a good performance of concrete roof tiles which comply with Malaysia Standard.

The Quality of Rainwater Collected from Roofs and the Possibility of Its Economic Use

The large temporal and spatial variability of rainwater quality, as well as the relatively small number of tests, makes the preliminary assessment of its economic exploitation difficult. Determining the relationship between the conditions and location of rainwater collection and rainwater quality would help indicate the range of options for rainwater use, as well as the parameters that require improvement. The aim of the presented article is to establish the physical, chemical, and microbiological parameters of different rainwater sources and, from the results obtained, determine the possibilities for its safe use in households. The research was carried out for two years. Samples of rainfall were collected from spring to fall from the following roofing materials: Concrete roof tiles, ceramic roof tiles, galvanized steel sheet, and epoxy-coated terrace. The physical, chemical, and microbiological quality were assessed on the basis of the pH, turbidity, electrical conductivity, the concentration of biogenic compounds, the concentration of chosen elements, the number of Escherichia coli, and the number of fecal streptococci. Significant bacterial contamination, decreased pH, and increased turbidity were identified in the water, depending on the parameters of the roofing washed by the rainfall and the intensity and frequency of precipitation.

Moist curing increases the solar reflectance of concrete

Abstract Most people are dwelling in cities, which contain a high density of buildings constructed of concrete or similar materials. Conventional grey-colored concrete is absorptive to solar radiation and discharges the absorbed heat to the air as sensible heat, contributing to the development of urban heat island. While existing studies have attempted to find high-reflective concrete by varying the components of the concrete mix, the influence of cured conditions on the albedo of concrete samples is still unknown and has not been reported. Here we first prepared 120 cement pastes with different water-to-cement ratios and different cementitious materials, and then cured the pastes in an indoor environment and a moist chamber, respectively. After cured in a moist chamber for 28 days and then cured in the air for 365 days, the spectral reflectance of all the pastes was tested. Experimental results indicated that the pastes cured in a moist chamber have an albedo that is 0.01–0.10 greater than those of the pastes cured in an indoor environment, with a greater albedo difference at relatively higher water-to-cement ratios. The results also revealed that when concrete productions, such as concrete roof tiles and concrete paver blocks, are prepared, it is practical to cure such productions in a moist environment to get a high albedo.

Lowering Emissivity of Concrete Roof Tile’s Underside Cuts Down Heat Entry to the Building

Buildings in Southern China widely use a double-skin roof to reduce heat entry through the roof to the building interior during summertime. Concrete roof tiles are preferably installed as the outmost layer of the double-skin roof due to their resistance to hail and wind damages and their attractive price. However, after construction, the tile’s top tends to be darkened by dust deposit and algae growth, increasing the heat entry through the roof to the building. Here, we show that this heat entry can be curtailed by lowering the emissivity at the tile’s underside. Temperatures and heat fluxes at different elevations of a double-skin roof with concrete tiles as the outmost layer of the roof are monitored. The underside of each concrete tile is coated with a specific paint to get a unique emissivity. Observations reveal that lowering the emissivity of concrete roof tiles could cut down the summer heat gain of buildings in tropical regions.

Carbon footprint and embodied energy assessment of roof-covering materials

The residential building sector regularly satisfies a diverse range of housing needs whilst addressing respective capital-cost considerations. Designers and builders must also be aware of the environmental implications of their design specifications; the work here adds to a body of knowledge concerned with carbon footprint and embodied energy demand, specifically through an examination of alternative roof-covering materials. A life cycle assessment (LCA) has been carried out, within a West Australian context, to compare impacts for the roof specification options of: clay tile; concrete tile; and sheet metal. In locations where recycling facilities are unavailable and thus disregarded, it is found that clay tiles have the lowest carbon footprint of 4.4 t of CO2 equivalent (CO2e-) and embodied energy demand of 52.7 Mega Joule (MJ) per 100 m2, while sheet-metal roofing has the highest carbon footprint (9.85 t of CO2e-), with concrete roof tiles having the highest embodied energy demand (83 MJ). Findings confirm that a sheet-metal roof can obtain significant carbon and embodied energy saving benefits (i.e. 71–73%) compared to clay tile or concrete roof covers through ongoing encouragement of recycling strategies and increased local recycling facilities able to embrace residual cradle-to-cradle material reuse.

THERMAL ANALYSIS OF URBAN LAND COVER USING AN UNMANED AERIAL VEHICLE (UAV) IN MEDELLIN, COLOMBIA

Thermal anomalies in built environments, known as Urban Heat Islands (UHI), are studied with satellite-derived data. However, this information is insufficient to examine regions such as the Aburra Valley, where the city of Medellin is located. In this valley, atmospheric interferences are common and the rugged terrain influences the amount of solar radiation reaching the surface, which hinders the analysis of the UHI. Unmanned Aerial Vehicles (UAVs) can be used to obtain the Land Surface Temperature (LST) at a time and location that is more convenient. In this project, a UAV was equipped with a thermal sensor to collect data on natural (ground vegetation and trees) and artificial (concrete, asphalt, and clay roof tiles) land cover types in Medellin, Colombia. The thermal information provided by the drone overcame the limitations of the satellite-derived data in terms of spatial, temporal, and radiometric resolution. This data enabled the study of specific land-cover types in different urban contexts, especially the influence of vegetation on LST. The findings suggested that the distribution of trees is crucial for UHI mitigation. Tree shading reduced the surface temperature of asphalt in average by 12 °C and by 5.7 °C for concrete. In addition, the presence of trees alongside streets reduced the maximum surface temperature of asphalt by 22.4 °C in the same neighborhood. These results contributed to the understanding of the influence of urban development on Medellin’s temperature.

THERMAL ANALYSIS OF URBAN LAND COVER USING AN UNMANED AERIAL VEHICLE (UAV) IN MEDELLIN, COLOMBIA

Thermal anomalies in built environments, known as Urban Heat Islands (UHI), are studied with satellite-derived data. However, this information is insufficient to examine regions such as the Aburra Valley, where the city of Medellin is located. In this valley, atmospheric interferences are common and the rugged terrain influences the amount of solar radiation reaching the surface, which hinders the analysis of the UHI. Unmanned Aerial Vehicles (UAVs) can be used to obtain the Land Surface Temperature (LST) at a time and location that is more convenient. In this project, a UAV was equipped with a thermal sensor to collect data on natural (ground vegetation and trees) and artificial (concrete, asphalt, and clay roof tiles) land cover types in Medellin, Colombia. The thermal information provided by the drone overcame the limitations of the satellite-derived data in terms of spatial, temporal, and radiometric resolution. This data enabled the study of specific land-cover types in different urban contexts, especially the influence of vegetation on LST. The findings suggested that the distribution of trees is crucial for UHI mitigation. Tree shading reduced the surface temperature of asphalt in average by 12 °C and by 5.7 °C for concrete. In addition, the presence of trees alongside streets reduced the maximum surface temperature of asphalt by 22.4 °C in the same neighborhood. These results contributed to the understanding of the influence of urban development on Medellin’s temperature.

Balancing of life cycle carbon and cost appraisal on alternative wall and roof design verification for residential building

PurposeThe purpose of this study is to describe life cycle cost (LCC) and life cycle assessment (LCA) evaluation for single story building house in Malaysia. Two objective functions, namely, LCA and LCC, were evaluated for each design and a total of 20 alternatives were analyzed. Two wall schemes that have been adopted from two different recent studies toward mitigation of climate change require clarification in both life cycle objectives.Design/methodology/approachFor this strategic life cycle assessment, Simapro 8.3 tool has been chosen over a 50-year life span. LCC analysis was also used to determine not only the most energy-efficient strategy, but also the most economically feasible one. A present value (PV)-based economic analysis takes LCC into account.FindingsThe results will appear in present value and LC carbon footprint saving, both individually and in combination with each other. Result of life cycle management shows that timber wall−wooden post and beam covered by steel stud (W5) and wood truss with concrete roof tiles (R1) released less carbon emission to atmosphere and have lower life cycle cost over their life span. W5R1 releases 35 per cent less CO2 emission than the second best choice and costs 25 per cent less.Originality/valueThe indicator assessed was global warming, and as the focus was on GHG emissions, the focus of this study was mainly in the context of Malaysian construction, although the principles apply universally. The result would support the adoption of sustainable building for building sector.

The Comprehensive Comparison of Thermal and Physical‐Mechanical Properties of the Recycled Rubber and Plastic Roofing Tiles versus Roofing Tiles Made with Different Traditional Materials

The objectives of this research were to estimate the thermal transmittance and some physical‐mechanical properties of a housing cover built with roofing tiles made from recycled plastics and rubber and compare them with three other traditional solutions for housing cover: ceramic roofing tiles, concrete roofing tiles, and zinc sheets. This roofing tile has technical advantages over the others, due to its higher thermal insulation, higher resistance to freezing, higher resistance to hail, higher flexural resistance, lower specific weight, and lower water absorption, with lower cost than the traditional glazed black ceramic roofing tile. And it is also friendlier to the environment.

Water footprint and life cycle assessment of concrete roof tile and brick products at PT. XYZ

PT. XYZ is an Indonesian company engaged in manufacturing concrete roof tile and paving block. The company has not paid attention to the environmental and human health aspects of their production activity, where there is so much water used and discarded during the production process and no water treatment for the wastewater produced. Therefore this topic proposed in order to determine the resulting impacts from the production processes of concrete roof tile and brick at PT. XYZ on the environment and human health. The impact on the environment and human health were identified through water footprint assessment (WFA) and life cycle assessment (LCA). Through the WFA accounting, it is known that the amount of water needed to produce a concrete roof tile is 21.384 L which consists of 16.433 L blue water and 4.951 L grey water, whereas for a brick is 10.496 L which consists of 10.48 L blue water and 0.016 L grey water. With ReCiPe midpoint (H) method, it is known that the dominant impact categories generated in one batch production processes of concrete roof tile and brick are natural land transformation, marine eco-toxicity, freshwater eutrophication, and freshwater eco-toxicity, where those impact categories represent the average of 75.5% from overall impact category for concrete roof tile and brick products.

Regulating top albedo and bottom emissivity of concrete roof tiles for reducing building heat gains

In Southern China concrete tile roof is widely used as double-skin roof to shield sunlight directly on the roof deck. Colony of dust and algae rapidly reduces the albedo of the tile’s top after construction, increasing the heat gain of the interior building during summer months. Here we show a simple retrofit strategy by decreasing the tile’s bottom emissivity and increasing the tile’s top albedo simultaneously. A building cell housed for concrete tiles with different tile’s top albedo and with different tile’s bottom emissivity is built to monitor the temperatures of the roof at different elevations. The temperatures observed at the roof tile and at the roof deck indicate that both decreasing the tile’s bottom emissivity and increasing the tile’s top albedo can effectively decrease the roof deck temperature and reduce the heat gain of the building. We speculate that increasing the tile’s top albedo and decreasing the tile’s bottom emissivity should be done simultaneously to retrofit concrete tile roofs for reducing the heat gains of buildings in summer months.

Mathematical model of consolidation of fine concrete mixtures with different mobility, casted by vacuumizing and axial pressing in layers

A mathematical model allowing establishing regularities in the consolidation processes of fine-grained concrete mixtures with different mobility and compaction methods has been worked out. This study is based on two-phase systems and nonlinear character of their consolidation. It resolves the question of the choice of vacuumizing optimal parameters and axial pressing in layers for molding of thin-walled products such as concrete roof tiles and concrete pipe products. Finally, we can get products without heat treatment by the materials and energy-saving technologies.

Life Cycle Cost and Energy Analysis of Roof Systems for a Single-Family House

In this study, the life cycle cost (LCC) and energy consumption of a residential home were evaluated to find the lowest LCC among 12 roof systems. EnergyPlus 8.3 program was employed to estimate the annual cooling requirements of a two-storey house with total area of 240m 2 . The analysis was carried out for four types of roof insulation (aluminum foil, fiberglass, polystyrene and polyurethane)and three types of roof tires (concrete, ceramic and fiber cement).The concrete roof tiles without insulation were set as the baseline case. Results show the concrete roof tiles with fiberglass insulation provide the highest energy saving in the air conditioning system at 10.98%. However, the roof using fiber cement roof tiles with polystyrene insulation was found to be the most cost effective roof system. It shows the lowest LCC with the reduction in LCC by 3.31%.

Assessment of thermal cracking in concrete roof tiles

Roofing system durability or service life depends greatly on the resistance of the system to climatic effects. In arid regions, the environmental temperature plays a major role in the performance of roof tiles. The temperature difference between the internal and external tile surfaces is one of the important parameters that control the characteristic of the thermal crack. This paper numerically investigates the thermal performance of concrete roof tiles widely used as roof covering material in Australia. A 3-D finite element model of the roof tile was developed in ATENA software. The field monitored temperature data at the inner and outer surface of the tiles was used to analyse the thermal performance. Further, a parametric study was conducted to quantify the effect of material property and thermal loading. It was observed that the temperature difference between the inner and outer surface of the tile has the significant effect on the crack width, however the rate of cooling of the top surface does not have an effect on the crack width. Finally, a probabilistic crack width damage model was developed as a function of the temperature difference. This can be used to assess the vulnerability of concrete tile subjected to thermal load.

Investigating a wind tunnel method for determining wind-induced loads on roofing tiles

Current design loads for roofing tile systems in the U.S. are determined based on a standardized wind tunnel testing method developed in the 1990s to examine wind-induced pressures on the upper and lower surfaces of the tile. The method neglects several key parameters that are well known to affect wind loading (e.g. wind angle, specimen shape, etc.). The research objective of this study is to investigate this method by [1] characterizing wind-induced surface pressure distributions on field tiles for varying wind angles of attack and [2] measuring load path intensity through mechanically fastened tile attachments. Surface pressure distributions were measured on three full-size, rapid prototyped roofing tile models with 256 pressure taps immersed in wind flows. The models are geometrically identical to low-, medium- and high-profile concrete roofing tiles that are widely used in high wind areas. Additionally, their real counterparts were instrumented with load cells to measure reaction forces at mechanical fasteners. The results highlight areas of the method that are lacking in specificity and shows that low-resolution pressure measurement may yield conservative parameters for low- and medium-profile tiles but is potentially not conservative for asymmetric (s-shaped) high-profile tiles.

Achieving environmentally friendly building envelope for Western Australia’s housing sector: A life cycle assessment approach

Abstract The rapid growth of Western Australia’s population and economy will affect the sustainability of its building sector. The energy consumption of all processes during mining to material production, transportation, construction plant and tools, and operation (heating, cooling, lighting, hot water and home appliances) stages causes high greenhouse gas (GHG) emissions and embodied energy (EE) consumption. The literature review to date have confirmed that the building envelope consisting of exterior walls, windows, external doors, roof, and floor could significantly affect the energy consumption during operation stage. Australian construction industry could thus enhance the energy efficiency of the building envelope in order to achieve its GHG emissions reduction targets. This paper has assessed the GHG emissions and EE consumption associated with the construction and use of a typical house in Perth for sixty building envelope options using a life cycle assessment (LCA) approach. The results show that the building envelope consisting of cast in situ sandwich wall with polyethylene terephthalate (PET) foam core, double glazed windows, and concrete roof tiles has the lowest life cycle GHG emissions and embodied energy consumption.

THE THERMAL PERFORMANCE OF MANUFACTURED CONCRETE ROOF TILE COMPOSITE USING CLAY AND RICE STRAW FIBRES ON A CONCRETE MIXTURE

This paper presents a review of research on the development regarding concrete roof tile composite using clay and rice straw on concrete mixture to produce sustainable building materials in reducing indoor temperature during hot and dry weather. Architects today are less stressed about the impact and significance of roofing material to reduce indoor air temperature in the building design. Concrete roof tile is an exceptionally strong product and can endure wind and storm that would tear up other roofing types. Because of its excellent strength, concrete roof tile can withstand lifetime of your home. It is less expensive than many of the roofing tiles that it competes with a wonderful combination and its longevity. Nevertheless, concrete roof tile is non-heat insulation and also rather heavy. The combination of concrete with clay can make the concrete roof tile as a bad conductor, become heat insulation material and reduce indoor temperature level. Rice straw is the natural fiber consists of great thermal to improve indoor air quality and alleviates the issue of the weak mechanical strength of combination with concrete and clay. Besides, it can reduce the density of concrete because it has a lower density than other fibers.