Search Results (28)

During roof renovations, large quantities of waste BBRM (bitumen-based roofing materials) are generated, and the possibilities for recycling these materials have so far been very limited. In general, they can be crushed and mixed with asphalt to pave roads or can be burned for energy. While waste plastic materials are often recycled, the remelting process significantly degrades their durability and mechanical properties. Unlike conventional methods, our recycling process results in a material with properties that are in many ways superior to the original materials. It is durable, weather resistant, and has exceptionally high mechanical strength. This material can be used to produce various construction components, including replacing quickly degradable wooden parts in structures. The composite material demonstrates increased flexibility, enhanced tensile strength, and improved resistance to ultraviolet (UV) radiation and environmental degradation compared to standard bitumen. The process is simple and can be carried out directly at the renovation site using a portable device. Full article

In North America and Europe, asphalt shingle waste created during the installation of roofing membranes and tear-off shingles retrieved at the end of the membrane’s life cycle are two major sources of municipal solid waste. Since almost 15–35% of recycled asphalt shingles (RAS) consist of an asphalt binder, the effective recycling of RAS into asphalt mixtures could also allow a reduction in the consumption of non-renewable resources such as asphalt binders. In this context, several studies investigating the use of RAS in asphalt mixtures can be found in the literature, although they exhibit widespread and sometimes conflicting information about the investigated materials, the mix preparation and testing methodologies and the experimental findings. Given this background, this review paper aims at summarizing the existing information and research gaps, providing a synthetic and rational picture of the current literature, where similar attempts cannot be found. In particular, different research studies show that the use of RAS in asphalt mixtures is an economical as well as an eco-friendly option. RAS with up to 20% by weight of binder or 5% by weight of aggregate/mixtures (eventually in combination with 15% reclaimed asphalt pavement aggregate) were found to be relatively suitable to improve the performance properties of asphalt mixtures, both in the laboratory and in the field. Adding RAS to asphalt mixtures could enhance their stiffness, strength and rutting resistance (i.e., high-temperature properties), while negatively affecting the mixtures’ fatigue and thermal cracking resistance. However, the addition of specific biomaterials (e.g., bio-binders, bio-oils) or additives to asphalt mixtures can mitigate such issues, resulting in lower brittleness and shear susceptibilities and thus improving the anti-cracking performance. On the other hand, the literature review revealed that several aspects still need to be studied in detail. As an example, RAS-modified porous asphalt mixtures (fatigue, rutting, moisture susceptibility and thermal cracking) need specific research, and there are no comprehensive research studies on the effects of the RAS mixing time, size and mixing temperature in asphalt mixtures. Moreover, the addition of waste cooking/engine oils (biomaterials) as asphalt binder rejuvenators in combination with RAS represents an attractive aspect to be studied in detail. Full article

This paper proposes a temperature-adaptive radiative cooling (TARC) coating with simple preparation, cost effectiveness, and large-scale application based on a thermochromic powder. To determine the energy efficiency of the proposed TARC coating, the heat transfer on the surface of the TARC coating was analyzed. Then, a typical two-story residential building with a roof area of 258.43 m² was modeled using EnergyPlus. Finally, the energy-saving potential and carbon emission reduction resulting from the application of the proposed TARC roof in buildings under different climates in China were discussed. The results showed that the average solar reflectivity under visible light wavelengths (0.38–0.78 μm) decreases from 0.71 to 0.37 when the TARC coating changes from cooling mode to heating mode. Furthermore, energy consumption can be reduced by approximately 17.8–43.0 MJ/m² and 2.0–32.6 MJ/m² for buildings with TARC roofs compared to those with asphalt shingle roofs and passive daytime radiative cooling (PDRC) roofs, respectively. This also leads to reductions in carbon emissions of 9.4–38.0 kgCO₂/m² and 1.0–28.9 kgCO₂/m² for the buildings located in the selected cities. To enhance building energy efficiency, TARC roofs and PDRC roofs are more suitable for use on buildings located in zones with high heating demands and high cooling demands, respectively. Full article

Rainwater runoff samples from a range of roofing materials were temporally collected from 19 small-scale roof structures and two commercial buildings through simulated and actual storm events, and the concentrations of polycyclic aromatic hydrocarbons (PAHs), phosphorus flame retardants (PFLs), and pyrethroid insecticides and other water quality parameters were analyzed. In Part I of this research, the concentrations of these contaminants in roof runoff and soils receiving runoff from a range of roofing materials were evaluated. In Part II, recommendations have been developed for a first-flush exclusion to improve the quality of water harvesting for nonpotable uses. Recommendations focus on a first-flush diversion based on mass removals of total suspended solids (TSS) and PAHs linked to conductivity measurements throughout a storm event. Additionally, an upper-confidence limit (UCL) was constructed to determine the minimum diversion required to obtain 50, 75, 90, and 95% mass removal of TSS and PAH contaminants. The majority of TSS were produced during the initial 1.2 mm of runoff. Likewise, the majority of PAHs were removed during the initial 1.2 mm of runoff, except for the asphalt shingle roofs, where high PAHs were observed after 6 mm of runoff. The Texas Water Development Board (TWDB)-recommended first-flush diversion of one gallon for every 100 square feet of rooftop was not always adequate for removing 50% of TSS and PAHs from the roofs. Rainwater runoff conductivity decreased drastically between 1.2 to 2.4 mm of rainwater runoff. Diverting the first flush based on conductivity has the potential to also divert the majority of TSS and PAHs in roof runoff. Full article

Rainfall runoff may be captured and stored for later use, but the quality of this water can be detrimental in some uses without the use of appropriately designed first-flush diverters. The rainfall runoff water quality was measured on nineteen new small-scale and two aged commercial roofs located near high traffic highways. Roof coverings included asphalt shingles, sheet metal, clay tiles, and tar and gravel. Runoff samples were evaluated for polycyclic aromatic hydrocarbons (PAHs), phosphorus flame retardants (PFRs), and pyrethroid insecticides. Eighteen small-scale roofs were subjected to a range of simulated rainfall events, while natural runoff was sampled on the commercial roofs and one small-scale roof. Runoff was analyzed for pH, conductivity, turbidity, total suspended solids, boron, iron, copper, zinc, manganese, sodium adsorption ratio, nitrate-nitrogen, seventeen PAHs, tris(2-chloroethyl) phosphate, tris(1,3-dichloro-2-propyl)phosphate, bifenthrin, cypermethrin, and lambda-cyhalothrin. Samples from four natural storm events were also analyzed for total coliforms and Escherichia coli. In addition, soils below seventeen existing gutter downspouts were sampled to determine long-term pollutant accumulation. Atmospheric deposition was the main contributor of pollutants in the roof runoff. A majority of samples fell within the U.S. EPA guidelines for non-potable urban and agricultural water reuse. Trace levels of PAHs, PFRs, and insecticides were detected, but all detections were three orders of magnitude below the USGS health-based screening level benchmark concentrations. Results indicate that diverting the first flush, based on turbidity, total suspended solids, or conductivity, can improve the overall water quality and reduce the concentrations of PAHs in harvested rainwater. Downspout soil sampling showed potential for the long-term accumulation of PAHs at concentrations exceeding the minimum human-health risk-based screening levels at these high runoff-loading locations. Full article

Solar geoengineering (SG) solutions have many advantages compared to the difficulty of carbon dioxide removal (CDR): SG produces fast results, is shown here to have much higher efficiency than CDR, is not related to fossil fuel legislation, reduces the GHG effect including water vapor, and is something we all can participate in by brightening the Earth with cool roofs and roads. SG requirements detailed previously to mitigate global warming (GW) have been concerning primarily because of overwhelming goals and climate circulation issues. In this paper, annual solar geoengineering (ASG) equations and estimated requirements for yearly solar radiation modification (SRM) of areas are provided along with the advantages of annual solar geoengineering (ASG) to mitigate yearly global warming temperature increases. The ASG albedo area modification requirements found here are generally 50 to potentially more than 150 times less compared to the challenge of full SG GW albedo mitigation, reducing circulation concerns and increasing feasibility. These reductions are applied to L1 space sunshading, Earth brightening, and stratosphere aerosol injection (SAI) SRM annual area requirements. However, SAI coverage compared to other methods will have higher yearly increasing maintenance costs in the annual approach. Results also show that because ASG Earth albedo brightening area requirements are much smaller than those needed for full mitigation, there are concerns that worldwide negative SG would interfere with making positive advances for several reasons. That is, negative SG currently dominates yearly practices with the application of dark asphalt roads, roofs, and building sides. This issue is discussed. Full article

The creation of the greenIZOLA Experimental Center results from a long-term collaboration between the Faculty of Civil Engineering, Technical University of Košice, and the construction company, IZOLA Košice, s.r.o. The project focuses on a four-story administrative building with four terraces and services, asphalt roads, and warehouses located in the industrial part known as Nad Jazerom, in Košice, Slovakia. This study examines the benefits of green roofs as a case study in green transformation processes. Green roofs have multiple benefits. In addition to reducing energy demands for heating and cooling through better insulation properties, green roofs can improve stormwater management and local water balances by mitigating water runoff and increasing local evaporation. They can reduce energy demands, improve stormwater management, and enhance biodiversity. The research involved comparing pre- and post-establishment data with simulations. The roof was divided into three test segments for temperature measurements throughout the year. External climatic parameters were monitored using a weather station and a pyranometer. Long-term temperature monitoring in the individual roof layers was also conducted. This data was crucial for validating the building energy demand simulation models, assessed using the SimStadt platform. The results showed a 15–40% reduction in U-values with different types of greening. The findings could encourage more widespread implementation of green roofs in Slovakia and Eastern Europe. Full article

Recent ground-based measurements find the magnitude of the urbanization effect on the global average annual mean surface air temperature corresponds to an urbanization contribution of 12.7%. It is important to provide modeling to help understand these results as there are conflicting concerns. This study models the global warming contribution that urbanization heat fluxes (UHF) can make due to anthropogenic heat release (AHR), and solar heating of impermeable surface areas (ISAs), with additional secondary effects. Results help explain and support ground-based observations. Climate models typically omit anthropogenic heat release (AHR) as warming estimates are below 1%. In agreement, the baseline assessment in this paper has similar findings. However, in this study, the methods of climate amplification estimates (MCAE) with data-aided physics-based amplification models are used. When the MCAE are applied at the global and microclimate levels that consider greenhouse gases (GHGs), feedback, and other secondary effects; the results show that AHR fluxes can amplify, increasing to have an estimated global warming (GW) influence of 6.5% from 1950 to 2022 yielding a 0.9% decade⁻¹ increase. This increasing rate due to energy consumption is found as anticipated to be reasonably correlated to the increasing population growth rate over this time. Furthermore, using the MCAEs, this paper studies heat fluxes assessment due to solar heating of unshaded impermeable surfaces including likely secondary amplification effects. Impermeable surface areas (ISAs) such as asphalt roads, roofs, and building sides have been reported with high land surface contact temperatures (LSCTs) relative to non-ISAs and significantly found to contribute to urbanization warming. Results indicate that high-temperature unshaded impermeable surfaces (including building sides) are estimated to average around 10–11 °C above the earth’s ambient temperature of 14.5 °C (showing albedo ISA estimates between 0.133 and 0.115 respectively); the ISA heat fluxes with secondary effects are estimated to have about a GW influence of 6.5%. This is broken down with average contributions of 4.0% from urban ISAs and 2.5% from rural ISA heat fluxes. Asphalt road ISA heat fluxes are estimated to have about a 1.1% global warming influence. Then the total UHF effect from ISAs and AHR with secondary effects is assessed in modeling to yield a combined average GW influence of 13% helping to confirm ground-based measurement results. Several key adjustment values were used for shading, cloud coverage, and rural-to-urban ISA ratios. Microclimate GHGs and related water vapor feedback (WVF) were assessed to increase urban warming by about 50%. As well an assessment of water vapor and radiation increases from UHF is provided. This study also shows the need to incorporate urbanization heat fluxes with secondary effects into climate models and indicates the necessity for Paris Agreement urban heat flux mitigation goals. Results also found that given average climate conditions, it is possible to mitigate much of the UHI effect with an albedo increase of 0.1 that is anticipated to lower the average impermeable surface temperatures by about 9 °C. Studies show this can be accomplished with cost-effective cool roads and roofs. Although roads are only estimated to occupy 14% of ISAs, changing roads from asphalt to concrete-type surfaces would improve reflectivity by about a factor of 5 and is estimated to mitigate about 5.5% of global warming. Unfortunately, the current overuse of black asphalt on pavements and roofs is highly dangerous to our environment causing UHI increases in heatwaves, excessive temperatures, and global warming issues and should be banned. Asphalt usage also reduces opportunities for solar geoengineering of urbanization. Full article

Recently, there has been an attempt to implement increasingly significant prefabrication in building construction, since this method is considered to represent an opportunity to reduce impacts in the construction sector. For pitched roofs, there have been relevant developments, such as sandwich panels, asphalt shingles, lightweight roof panels, among others. However, in relation to flat roofs, the advances have been of little relevance and are mainly limited to the improvement of technical characteristics and prefabrication of the construction materials used. The main goal of this article is to demonstrate the possibility of developing new solutions for more sustainable flat roofs in the carbon footprint, and for this purpose a system was developed called ADAPTIVE—Advanced Production System for Sustainable and Productive Roofing Retrofit, which consists of developing a composite solution for the rehabilitation of flat roofs, completely prefabricated and with zero waste, with the aim of increasing energy behaviour, collecting and storing rainwater, and using the roof as a garden leisure space. To obtain the validation results, computerised theoretical modelling was conducted with theoretical assessment of the components and the set of components developed, which allowed us to conclude that the system meets the high hygrothermal, acoustic, and structural requirements. Full article

Urbanization increases the urban land surface temperature (LST), challenging society and the environment. This study measured the LST of diverse land uses (LU) in Dallas–Fort Worth (DFW) using a high-resolution (8 cm) thermal infrared sensor onboard a small, unmanned aerial vehicle (UAV). LUs included park (PA), industrial (IA), residential low-cost (RLC), and residential high-cost (RHC) areas. LST was collected by the UAV at different times on eight nonconsecutive days. UAV-collected LST was compared with that from Landsat 8-9 and in situ measurements. RHC reported the highest mean LST, and PA showed the lowest mean LST. Dark-colored asphalt shingle roofs in RHC had the highest mean LST range at 35.67 °C. Lower LST was measured in shaded areas and under thick green cover, whereas areas with thin green cover occasionally reported higher LST than pavements. The micro-urban heat island (MUHI) was calculated between LUs and within land cover types (roof, pavement, green, and water). The MUHI varied from 4.83 °C to 15.85 °C between LUs and 0.2 °C to 23.5 °C within LUs for the less than 1 km² study area. While the UAV thermal sensor and Landsat demonstrated a similar trend of LST variation, the UAV sensor reported more intense MUHI. An average percent bias (PBIAS) of 5.1% was calculated between the UAV sensor and in situ measurements. This study helps inform the urban design process by demonstrating how land use decisions impact LST locally and provides valuable insight for studies concerned with fine-scale urban LST variability. Full article

This study proposes the technology of “runoff storage and seepage utilization” for achieving purification of road rainfall–runoff and presents a multi-level series purification system (PBT-GR) comprising porous asphalt pavement (PAP), a bioretention system (BS), a storage tank (T) and a hydroponic green roof (GR). The operation parameters of each component unit were optimized and the contribution of each unit to pollution was analyzed. The results showed that under typical simulated rainfall, the suspended solids (SS), total nitrogen (TN), total phosphorus (TP), Pb, Zn and Cu removal rates by filtration and interception of porous pavement were 62.26 ± 3.19%, 16.29 ± 1.74%, 29.27 ± 1.37%, 37.61 ± 2.58%, 35.57 ± 4.64% and 31.17 ± 3.27%, respectively. The average concentrations of SS, TN, TP, Pb, Zn and Cu in the effluent of the PBT-GR system were 14.70 ± 2.21 mg/L, 1.52 ± 0.24 mg/L, 0.14 ± 0.04 mg/L, 0.09 ± 0.04 mg/L, 0.11 ± 0.03 mg/L and 0.04 ± 0.01mg/L, respectively, which met the water quality standards recommended in the Chinese guidelines and showed a high adaptability to pollution load. The contents of pesticide residues and heavy metals in cultivated vegetables met the national standards. The period required to recoup the investment in the system was approximately 3 years, indicating its good economic feasibility. The present study can provide a valuable reference of the construction of an efficient, low consumption and sustainable urban stormwater treatment system and can contribute to the improvement in the quality of the urban water environment. Full article

The principal difficulty in extracting urban surface water using remote-sensing techniques is the influence of noise from complex urban environments. Although various methods exist, there are still many sources of noise interference when extracting urban surface water, and automatic cartographic methods with long time series are especially scarce. Here, we construct an automatic urban surface water extraction method from the combination of traditional water index, urban shadow index (USI), and land surface temperature (LST) by using the Google Earth Engine cloud computing platform and Landsat imagery. The three principal findings derived from the application of the method were as follows. (i) In comparison with autumn and winter, LST in spring and summer could better distinguish water from high-reflection ground objects, shadows, and roads and roofs covered by asphalt. (ii) The overall accuracy of Automated Water Extraction Index (AWEIsh) in Zhengzhou was 77.5% and the Kappa coefficient was 0.55; with consideration of the USI and LST, the overall accuracy increased to 96.0% and the Kappa coefficient increased to 0.92. (iii) During 1990–2020, the area of urban surface water in Zhengzhou increased, with an evident trend in expansion from 11.51 km² in 2008 to 49.28 km² in 2020. Additionally, possible omissions attributable to using 30m-resolution imagery to extract urban water areas were also discussed. The method proposed in this study was proven effective in eliminating the influence of noise in urban areas, and it could be used as a general method for high-accuracy long-term mapping of urban surface water. Full article

This paper presents the results of a survey that was undertaken to examine homeowners’ FireSmart mitigation practices and investigate existing incentives and barriers to uptake of FireSmart Canada’s recommended wildfire mitigation activities in the Urban Service Area of Fort McMurray Alberta. Single-family residential property owners, the large majority of whom were affected by the Horse River wildfire, were invited to participate in an online survey. A total of 496 surveys were completed, with a response rate of 38%. We found that most of the participants generally perceive a low to moderate wildfire risk to their properties: they felt there was a low chance of a catastrophic fire happening soon and/or ‘enough’ had already been done to reduce the immediate risk. Although about half of the participants searched for information about FireSmart, having information or knowledge of FireSmart did not translate into substantial adoption of recommended mitigation actions. Survey participants generally preferred and implemented more of the low-cost, low effort mitigation measures such as cutting grasses and cleaning debris, likely for reasons other than wildfire risk reduction. With regard to structural measures, we found asphalt shingles and vinyl siding were present on the majority of homes; although this was not a choice but was provided by the builder or on the home when it was purchased. Very few respondents were willing to replace their siding or roof––the cost was the single biggest factor. In addition, we identified several other factors as negatively influencing homeowners’ mitigation actions, including the tendency to shift responsibility to the municipal government and social pressure such as neighbors not being as proactive in completing FireSmart mitigation measures. Recommendations that may help promote positive wildfire mitigation behaviors are discussed. Full article

This study proposes the use of spatial high-resolution Formosat-5 (FS5) images for estimating total suspended matter (TSM) concentrations in a coastal region. Although many atmospheric correction methods are available, none of them are proposed to apply to FS5. Therefore, to remove the atmospheric effect, we performed a linear regression between the digital number (DN) of an FS5 image and the Landsat-8 Operational Land Imager (OLI) level-2 remote-sensing reflectance (Rrs) by using 160 samples of five ground targets. The ground targets, namely roof material, asphalt, water, vegetation, and other materials (sand and soil), were assumed to have negligible differences within 24 h. The results show that the linear model used for computing FS5 reflectance exhibited good coefficients of determination (R²) ranging from 0.87 to 0.96 for blue, green, red, and near-infrared bands. Next, in situ TSM measurements were not collected during the FS5 overpassing in Ha Long Bay, Vietnam, so we used two existing algorithms with a red band to estimate the TSM concentration. These algorithms developed for different coastal waters exhibited satisfactory agreement between derived field data and observed TSM concentrations with R² ranging from 0.86 to 0.95. We also cross-checked the accuracy of the FS5-derived TSM concentration through comparison with an OLI-derived TSM image. The OLI-derived TSM image was validated and discussed for Vietnamese coastal waters, including Ha Long Bay. Lastly, based on comparisons between FS5- and OLI-derived TSM images in terms of spatial distribution, histograms, and root mean square error, we indicated the FS5 images after the removal of atmospheric effects could be totally used for estimating TSM in coastal water regions. Full article

The urban heat island (UHI) effect increases the ambient temperatures in cities and alters the energy budget of building materials. Urban surfaces such as pavements and roofs absorb solar heat and re-emit it back into the atmosphere, contributing towards the UHI effect. Over the past few decades, researchers have identified albedo and thermal inertia as two of the most significant thermal properties that influence pavement surface temperatures under a given solar load. However, published data for comparisons of albedo and thermal inertia are currently inadequate. This work focuses on asphalt and concrete as two important materials used in the construction of pavements. Computational fluid dynamics (CFD) analyses are performed on asphalt and concrete pavements with the same dimensions and under the same ambient conditions. Under given conditions, the pavement top surface temperature is evaluated with varying albedo and thermal inertia values. The results show that the asphalt surface temperatures are consistently higher than the concrete surface temperatures. Surface temperatures under solar load reduce with increasing albedo and thermal inertia values for both asphalt and concrete pavements. The CFD results show that increasing the albedo is more effective in reducing pavement surface temperatures than increasing the thermal inertia. Full article