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Effects of UV Radiation on Building Materials
Abstract
During recent years there has been increasing use of polymer-based materials, such as thermoplastics, thermosets and composites, as replacements for the traditional building materials. Although these polymers offer an impressive range of attractive properties, the effect of climatic conditions on the durability and performance of these materials is not fully understood. This paper briefly examines the effects of the UV radiation on the performance and properties of the polymer-based building products. The use of accelerated weathering techniques to assist in assessing the durability of building materials is also briefly discussed.
... The second highest detected shape was that of paint particles, which are mainly generated by physical impacts and weathering on house and building surfaces [32,33]. In addition, when road-marking paint was detected and analysed, 200-300 µm glass beads were detected in the paint ( Figure S4). ...
Microplastics (MPs) are plastic particles < 5 mm in diameter, which are detected in air, soil, and water, causing various environmental problems. In total, 37.3% of MPs are generated from point pollution sources and 62.7% from non-point sources; most of the non-point-source MPs are from vehicles tires, road-marking paint, and bitumen used in road pavements. In this study, the concentrations of MPs generated from roads in Goyang city, South Korea, were examined in terms of the drying period (0, 1, 2, or 3 d). Road dust sampling was performed at the kerb and quantitative and qualitative analyses were conducted for each sample. The MP concentrations were 552 (±39) MPs g−1 for a 0 d drying period and 1530 (±602) MPs g−1 for a 3 d drying period, confirming that the MP concentration in road dust increased with the increase in drying period. Among the detected substances, black particles accounted for the highest proportion (72%) and were found to be bitumen and tyre particles. This study also confirmed that the MPs accumulated on roads were washed away when rainfall exceeded a certain amount.
... Changes to the ozone layer starting in the latter part of the 20 th century led to an increase in the proportion of UV-B radiations reaching the earth's surface. It potentially disrupts the biological life and processes, including damaging several non-life entities, including polymerbased materials, such as thermoplastics, thermosets and composites used as replacements for traditional building materials, through a phenomenon known as chalking (10,47). Ozone layer depletion resulted from rapid industrialization, high consumption of chlorofluorocarbons (CFCs) and halons, and global warming have further worsened the problem towards more destruction (48). ...
Solar ultraviolet (UV) radiation exposure is the primary etiological agent responsible for developing cutaneous malignancies. Avoiding excessive radiation exposure, especially by high-risk groups, is recommended to prevent UV-induced photo-pathologies. However, optimal sun exposure is essential for the healthy synthesis of about 90% of vitamin D levels in the body. Insufficient exposure to UV-B is linked to vitamin D deficiency in humans. Therefore, optimal sun exposure is necessary for maintaining a normal state of homeostasis in the skin. Humans worldwide face a major existential threat because of climate change which has already shown its effects in several ways. Over the last 4 to 5 decades, increased incidences in skin cancer cases have led international health organizations to develop strong sun protection measures. However, at the same time, a growing concern about vitamin D deficiency is creating a kind of exposure dilemma. Current knowledge of UV exposure to skin outweighs the adverse effects than the beneficial roles it offers to the body, necessitating a correct public health recommendation on optimal sun exposure. Following an appropriate recommendation on optimal sun exposure will lead to positive outcomes in protecting humans against the adverse effects of strict recommendations on sun protection measures. In this short review, we spotlight the ambivalent health effects of UV exposure and how ozone layer depletion has influenced these effects of UVR. Further, our aim remains to explore how to lead towards a balanced recommendation on sun protection measures to prevent the spurt of diseases due to inadequate exposure to UV-B.
... The large NIR reflectivity of 0.82 and UV-resistant property (Detailed in Section S6 and Fig. S9 in the Supplementary Information) make it more attractive for building applications compared to commercial white paints. The advantages of the polymer coating over white paints pave the way for potential applications in surface radiative cooling for buildings and spacecraft since they both suffer from heavy UV irradiation and UV rays damage the modern buildings gradually as reported before 36 . Additionally, it is noted that PDMS is not the only choice for the matrix material. ...
While most selective emitter materials are inadequate or inappropriate for building applications, here we present a techno-economically viable optical coating by integrating glass bubbles within a polymer film. A controlled glass bubble volume concentration from 0 to 70% leads to a selective solar reflectivity increase from 0.06 to 0.92 while the mid-infrared emissivity remains above 0.85. Outdoor measurements show the polymer coating on a concrete surface can provide a temperature reduction up to 25 °C during the day when conduction and convection are limited and a net cooling power greater than 78 W/m² at a cost less than $0.005/W. The impact of polymer coating on common buildings is estimated as potential annual energy savings of 2–12 MJ/m² and CO2 emission savings of 0.3–1.5 kg/m². More savings are expected for higher surface-area-to-volume-ratio buildings, and the polymer coating is also expected to resolve cooling issues for old buildings with no air conditioning.
... Results indicate to great color stability and better efficiency of Silicone oil for preserving of visual and aesthetic values of leather relics after accelerated aging process with compared to polyethylene glycol (with or without ascorbic acid). Color Change results from production of double bonds in organic materials, which act as the chromophoric groups (Timar-Balazsy and Eastop 2012: 17;Crabbe 1971: 150;Jones 2002). According to results of FTIR spectroscopy, oxidation of PEG produces new carbonyl groups as chromophoric agent (koochakzaei et al. 2014). ...
Lubricants and leather dressings are the most common treatments of dry and waterlogged historical leathers. Color change has a great importance during the time and treatment process, due to visual and aesthetic values of historic leather relics. Polyethylene glycol (PEG) and silicone oil (SiO) are frequently used leather dressings in the conservation procedures. Therefore, color stability of treated leathers with PEG and SiO were investigated before and afterheat accelerated aging. Moreover, application of ascorbic acid was evaluated as an antioxidant additive for PEG (PEG+AA).Color change after treatment and aging were studied by colorimetry technique in the CIE *L*a*b system. Results indicated to severe color alteration in PEG treated and aged leathers with or without ascorbic acid. Whereas, SiO treated samples showed better stability and minimum color shift after aging. Silicone oil was characterized as the best dressing for historical leathers with compared to PEG and PEG+AA, due to its high stability and aesthetical properties.
... This can have consequential effects on the salvage and reuse of those components. As background, New Zealand has an environment that is harsh toward building materials 84 . The country enjoys very clear skies owing to strong and consistent winds that remove pollution. ...
This paper discusses the state of deconstruction in New Zealand. It outlines specific circumstances in New Zealand which affect deconstruction and materials reuse. The paper details techniques, strategies and examples of deconstruction in New Zealand, and provides an overview of legislation, guidelines, governmental bodies and industry organisations that are associated with construction and demolition as well as waste minimisation in New Zealand. The key document relating to the potential for wide spread implementation of deconstruction and other materials reuse strategies in New Zealand is the recently published a strategy document 'The New Zealand Waste Strategy – Towards Zero Waste and a Sustainable New Zealand 2002 1 , which sets the nation a target of reducing construction and demolition waste going to landfills by 50% of the 2005 figure by 2008. Half of the Territorial Authorities in New Zealand have set themselves the even more ambitious target of zero waste by 2015.
... Although these polymers offer an impressive range of attractive properties, the effect of climatic conditions on the durability and performance of these materials is not fully understood. However, the outdoor environment contains several elements that are destructive to organic polymers, such as moisture, acid rain, temperature cycling, and ultraviolet (UV) radiation [1]. In both the USA and Western Europe about 20–30% of the annual production of plastic resin is used by the building sector [2]. ...
The increased use of fiber-reinforced polyester composites in an outdoor environment has led to questions concerning the environmental durability of these materials, particularly as related to ultraviolet (UV) exposure. In this research the effects of UV radiation on mechanical properties of glass/polyester composites were studied. Since the photo degradation is a surface mechanism and is restricted to degradation of mechanical properties of resin (fiber is not degraded), this research is focused on resin properties. For this reason, test samples made of polyester resin were prepared and treated in a UV chamber through accelerated tests. Three types of specimen were manufactured. The tensile testing samples were prepared based on ASTM D638 standard with a nominal thickness of 1 mm. Also, Arcan specimens for shear tests and ASTM D3410 for compression tests were manufactured. To obtain time dependent mechanical properties of polyester resin under UV radiation, samples were radiated in three different time intervals, equivalent to 3, 6 and 12 months, using an artificial UV exposure chamber. Test specimens were tested under tension load and showed a decrease of up to 15% in average failure strain, a decrease of up to 30% in ultimate strength, and 18% decrease in tensile modulus after 100 h exposure. Also, significant changes were considered in shear modulus and strength of polyester. The effect of ultraviolet absorbers (UVA) on preventing polyester mechanical properties degradation is also studied. The results showed that the samples which have UVA additives were not degraded after UV exposure.
This chapter reviews the potential impact of six environmental agents (water, ice, wind, fire, solar radiation and chemical attack) on the long-term stability of earth buildings together with some of the most common techniques for measuring and improving material durability. Liquid water appears the most detrimental of all environmental agents, not only because it can significantly reduce capillary cohesion inside the material but also because water can penetrate inside buildings through multiple routes, e.g. rainfall, foundation rise, ambient humidity and utilities leakage. Water can also be very damaging when it is present in solid form as the expansion of pore ice may induce cracking of the earth material. The high resistance of earth buildings to wind is instead proven by the good conditions of many historic structures in windy regions. Earth buildings also exhibit good resistance to fire as the exposure to very high temperatures may even improve material durability. Solar radiation has, in general, a beneficial effect on the stability of earth buildings as it promotes water evaporation with a consequent increase of capillary cohesion. Solar radiation may, however, have a detrimental effect if the earth is stabilised by organic binders that are sensitive to photodegradation because, in this case, it may produce material damages ranging from a simple surface discoloration to a much more serious deterioration of the intergranular bonds. Unstabilized earth is generally inert and, hence, largely unaffected by chemicals though, in some instances, the precipitation of salt crystals inside the pore water can induce material cracking. Chemical degradation can instead be severe in both stabilised earth (due to the dissolution of intergranular bonds) and steel-reinforced earth (due to the corrosion of rebars). No international standard protocol exists to measure the durability of earth materials, which is currently assessed by multiple experimental procedures depending on which environmental agent is considered. Testing standards may, however, be devised in the future by differentiating between weathering protocols, which reproduce the effect of each agent on the earth sample, and durability protocols, which adopt a unique experimental procedure to measure a given material property regardless of weathering history.
Optimum UV pretreatment of polystyrene (PS), polyethylene (PE) and polyethylene terephthalate (PET) plastics for their efficient biodegradation were evaluated in this study. It was found that a longer incubation time and shorter distance to UV source (t2 d2 condition) (UV dose of 7.02 × 10¹² μW.cm⁻².s) resulted in a higher roughness, hydrophilicity, microbial viability, biofilm formation, surface degradation, and a more significant physical and molecular weight reduction. The highest biodegradation within 45 days happened to PE and PS with respective 7.8 and 5.13% physical weight loss, and 4.71 and 2.1 fold molecular weight reduction compared to the “un-pretreated & strain-free bio-treated” (control-3). The hydrophilicity of PS and PE were increased to the “UV-pretreated & bio-treated” samples with a reduction in water contact angle from 105° to 5° in PS and 102° to 60° in PE. Microscopic analysis indicated significant surface property changes or degradation (cracks and holes) on “UV-pretreated & bio-treated” samples. The thermal gravimetric analysis also showed 73, 25 and 20 °C reductions in degradation temperature of “UV-pretreated & bio-treated” PE, PS and PET, respectively. Chemical transformation revealed new peaks in “UV-pretreated & bio-treated” samples, indicating the positive role of UV in biodegradation efficiency. Statistics analysis showed that 45 days was adequate to obtain optimum biodegradation efficiency (p< 0.05).
The effects of moisture, temperature, and ultraviolet (UV) light on performance of natural-fiber–plastic composites (NFPC) were assessed. We conducted short-term tests in the laboratory and long-term tests under natural exposure and measured changes in mechanical properties and color in samples of the composite. Chemical changes of the composite's materials were measured by X-ray photoelectron spectroscopy to elucidate the mechanisms of chemical transformations on the material surface. Relative humidity highly affected the modulus of rupture (MOR) and the modulus of elasticity (MOE), and had a greater effect than temperature and UV exposure on performance of the composite. The lightness of the composite was increased by the UV effect in the short- and the long-term tests. The X-ray photoelectron spectroscopy (XPS) analysis suggested that the composite was protected by the UV absorber. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 99: 2570–2577, 2006
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