Electrothermal and Optical Properties of Hybrid Polymer Composites

The Electrothermal and optical properties of hybrid polymer composites made of poly (ethylene oxide) (PEO) matrix filled with different zinc oxide (ZnO) concentrations (0, 2, 4, 6 and 12 wt %), and strengthened with iodine (0.1 wt %) have been investigated. The electrical properties have been studied using the impedance technique as a function of ZnO concentrations, applied frequency ranges from 10 KHz to 3 MHz, and temperature in range (25-55 ˚C). The AC electrical properties showed frequency, temperature, and zinc oxide dependence. It was found that with increasing the ZnO concentration and with decreasing the applied frequency the dielectric loss and dielectric constant will be increased. The determined activation energy decreases with increasing the ZnO content and iodine charge complexes. The thermal conductivity has been studied, and it was found that the thermal conductivity increases with both ZnO concentration and temperature. The optical properties have been examined as a function of ZnO concentration, and applied UV-wavelength ranges from 300 to 800 nm. The determined optical dispersion parameters, such as the optical energy and refractive index are discussed

Climate impact optimization in concrete bridge construction

Estimates indicate that the total climate impact, from a lifecycle perspective, generated bySwedish construction processes reaches the same magnitude as emissions from all passenger carsin Sweden. A large part of the emissions from construction of roads and railways arise fromproduction of steel and concrete used in bridges and other infrastructure structures. In thisresearch, several cases of existing concrete bridges have been investigated. The case studies are ina very firm way analyzed, and then opportunities for reducing climate gas emissions are describedand elaborated upon. Accordingly, design and dimensioning through the use of today’s technologyand material selection are discussed. Without developing new ways to construct bridges, orcomparing concrete with other materials, a useful guide on how to use technology andopportunities that are available for constructing climate smarter versions of standard bridgestoday is developed and described

Klimatoptimerat byggande av betongbroar

Sammanfattning: Klimatp\ue5verkan fr\ue5n infrastrukturen (byggande, drift och underh\ue5ll) \ue4r betydande. I Sverige st\ue5r den f\uf6r cirka 5-10 procent av v\ue4g- och j\ue4rnv\ue4gstransporternas totala klimatp\ue5verkan ur ett livscykelperspektiv. En stor del av utsl\ue4ppen fr\ue5n byggande av v\ue4gar och j\ue4rnv\ue4gar kommer fr\ue5n tillverkningen av st\ue5l och betong som anv\ue4nds i broar och andra byggnadsverk.Projektets syfte var att unders\uf6ka hur klimatsmart man kan bygga en vanligt f\uf6rkommande betongbrokonstruktion som en plattrambro. Tanken \ue4r att p\ue5 ett mycket konkret och handfast s\ue4tt analysera och beskriva m\uf6jligheter f\uf6r reducering av klimatgasutsl\ue4pp som st\ue5r till buds med dagens b\ue4sta tillg\ue4ngliga teknik f\uf6r utformning och dimensionering samt materialval. Ytterligare ett syfte \ue4r att f\uf6rse branschen med praktiskt anv\ue4ndbara r\ue5d och v\ue4gledning f\uf6r att underl\ue4tta f\uf6r anl\ue4ggningsbranschen att m\uf6ta de krav p\ue5 reducering av klimatgaser som Trafikverket planerar att inf\uf6ra f\uf6r byggande av infrastruktur.I projektet har m\uf6jligheter att minska klimatgasutsl\ue4ppen fr\ue5n byggande och underh\ue5ll av plattrambroar analyserats utifr\ue5n ett livscykelperspektiv f\uf6r f\uf6ljande \ue5tg\ue4rder:- Produktval armering-\ua0Produktval cement-\ua0Tillsatsmaterial i betong-\ua0Val av betongkvalitet och typ-\ua0Konstruktiv optimering av m\ue4ngder-\ua0Minimering av spill-\ua0Optimering av transporter-\ua0Estetiska val-\ua0Optimering ur underh\ue5llsperspektiv-\ua0Val av produktionsmetodResultaten fr\ue5n projektet visar p\ue5 att det med ett aktivt och medvetet klimatarbete, och en kombination av materialrelaterade och utf\uf6randerelaterade \ue5tg\ue4rder, ofta finns m\uf6jligheter att reducera klimatbelastningen fr\ue5n en vanlig plattrambro med i storleksordningen 50%. Slutredovisningen utg\uf6rs av rapporten "Klimatoptimerat byggande av betongbroar", Stefan Uppenberg, Daniel Ekstr\uf6m och Ulf Liljenroth, samtliga WSP, och Nadia Al-Ayish, RISE (44 sidor och en bilaga)

Beyond metropolitanism and nativism: Re-grounding media theory

While de-Westernisation is an interesting political intervention in media theory, analytically it offers little. We critique this approach through six inter-related arguments. The first point of critique challenges the putative singularity of the West. The second line of enquiry raises questions about the emergence of new academic disciplines and their intellectual offerings. Our third point is that the call to de-Westernise Media Studies is naïve, ignores history and the long patterns of global interconnectedness that have mutually formed the West/Rest. The fourth argument is that "de- Westernisation" suggests that the theory and methods of Media Studies offer nothing of use outside their original birthplaces, while the fifth argument is the conceptual danger of nativism. The sixth critique centres on the problem of essentialising culture as a determinate object. Examining the contemporary media practices of the Islamic Republic of Iran, we suggest that the true alternative to a repressive theocracy is its internal challenge by women, students and other parts of civil society that offers a critical third way beyond the binary divide

Environmental Impact of Concrete Structures - with Focus on Durability and Resource Efficiency

Concrete is essential for the construction industry with characteristic properties that make it irreplaceable in some aspects. However, due to the large volumes consumed and the energy intense cement clinker production it also has a notable climate impact. In order to reach the international and national sustainability goals it is therefore important to reduce the climate impact of concrete structures. There are many ways to influence the environmental impact of concrete and a detailed analysis is one of the actions that could push the industry and the society towards a sustainable development. The purpose of this research is to evaluate the environmental impact of concrete structures and the built environment and to highlight the possibilities to reduce that impact with choice of concrete mix and innovative design solutions. A life cycle assessment (LCA) was carried out to analyze the environmental impact of two thin façade solutions with innovative materials and to evaluate influences of different greenhouse gas reducing measures on concrete bridges. The influence of supplementary cementitious materials (SCM) in terms of climate impact and durability was also analyzed. The results indicate that SCMs have a twofold effect on the climate impact of reinforced concrete structures. Not only do they reduce the greenhouse gases through cement clinker replacement but also by an improvement of durability regarding chloride ingress. Currently, this is not considered in the regulations, which makes it difficult to foresee in LCA at early design stages. The results also show great possibilities to reduce the climate impact through different measures and design alternatives and the need for further development of products and solutions.QC 20171002</p

Miljövärdering av resurssnål betong med införande i BIM

This thesis aims to illustrate how environmental impact can be reduced, through the use of lean concrete. It also illustrates how environmental data can be applied to a house through implementation with BIM. In this study a unique concrete structure developed by Swedish Cement and Concrete Research Institute is assessed for environmental impact, by calculating the carbon dioxide equivalents using LCA methodology. The construction is a sandwich element where the concrete is made ​​up of three layers. Two external high-strength layers and a middle layer of low-strength concrete. The result is compared with three different concrete recipes. The environmental data obtained is then integrated with a building model in the BIM tool Autodesk Revit, using an own developed method. The purpose is to perform a sensitivity analysis in which the bearing walls are replaced with these concrete recipes. By performing a sensitivity analysis the effect the concrete has on an entire building can be seen. The result shows that there are major differences between the concretes. By only replacing the bearing interior walls to greener alternatives of the same material the climate impact is reduced by 10% of the building's overall climate impact. This study also shows that the resource efficient concrete has a lower climate impact than a standard concrete of the same strength class. The advantage is that this type wall construction can be made thicker without getting a significantly higher climate impact

Climate impact of BioZEment in the construction of residential buildings in Norway

The construction sector is a major contributor to global warming. One solution to the challenge is to develop new sustainable material alternatives. The BioZEment concept employs bio-catalytic dissolution and precipitation of calcium carbonate as a novel alternative to concrete. In this report, the reduction in global warming potential of using BioZEment is assessed with a building stock model, where the use of conventional concrete is compared to the use of BioZEment in Norwegian dwellings until 2100. The assessment is conducted with the assumption that BioZEment has expected material properties and is gradually penetrating the building stock until it reaches a full implementation by 2050. Results indicate that the use of BioZEment has a higher potential of reducing global warming potential than conventional concrete, regardless of the development of the cement industry. BioZEment could decrease cumulative greenhouse gas emissions with ca 15 % by 2100 compared to using conventional concrete with a conservative development and slightly less if compared to using concrete with an optimistic development (including among other initiatives breakthrough technologies like carbon capture and storage, and carbon capture and utilization). Results also indicate that, while BioZEment is not fully implemented in the entire building stock, using the optimistic development concrete instead of conservative concrete provides the lowest cumulative emissions by 2100. That means that including several migration strategies at the same time will reduce emissions further than taking one single action. The building stock model provides interesting indications about the potential of BioZEment, which can guide further development. If Norway is to meet its ambitious goals of emission reductions and climate neutrality, it is important to design thought through and robust strategies for the construction sector

Sustainability Aspects of New Admixtures and Supplementary Cementitious Materials for Durable Concrete

s the global population is growing and changing the globalization direction towards large city areas the needs for the development of infrastructure and housing will increase. In order to have a safe and sustainable construction the infrastructure needs to be not only sustainable but also durable. In some cases, the concrete is subjected to severe environments, e.g., elevated or high temperatures, de-icing salts, seawater exposure or acidic environment, which means increased demand to extend the service life beyond what is prescribed in the design codes. The sustainability of concrete infrastructures is highly dependent on the durability. A longer service life with low repair work reduces the greenhouse gas emissions. Various admixtures and cement supplementary materials may increase the durability of the concrete. However, it is also important to consider the embodied impact and safety issues concerning innovative nanomaterials as well as application of slag and fly-ash in concrete and their future availability on the market. Here we present an overview on the latest developments on the durability and sustainability of climate-optimized concrete

Livslängden hos betongbroar: Erfarenheter och implementering med LCA/LCC [Elektronisk resurs]

The lifespan of construction works is crucial to achieve a low environmental impact for aprovided function. Supplementary cementitious materials are increasingly used in concrete production where the effect on the service life of structures needs to be assessed. In order to achieve a long service life, the design, flexibility in the design and workmanship also needs to be addressed.Today’s LCC and LCA analyses are based on statistics of service life of older bridges and are not material specific. There is still a lack of information about how the service life of concrete bridges is affected by different measures. The overall goal of this project was to close this information gap. The project aimed at describing key factors that affect the lifespan of concrete bridges. Key factors may reflect aspects of both durability and the utility of the design. The purpose was to investigate how the service life can be included in LCA and LCC analyses and to create a basis for future LCA and LCC analyses of concrete road bridges.Factors affecting the service life of concrete bridges have been identified through a literature survey and interviews. The studies comprised the service life of concretebridges, durability, service life models, requirements and guidelines, previous LCA and LCC studies as well as service life-extending measures throughout the whole lifecycle from material production to the end-of-life.The studies showed that reinforcement corrosion caused by chlorides is the most common cause of damage in concrete bridges where the service life of parts of theconstruction is usually shorter than the design service life. Even though frost resistance has historically been more restricting when choosing a concrete composition. The restrictions have, however, been reduced lately but there needs to be more focus on finding a design method that takes into account the impact of the concrete composition regarding reinforcement corrosion in order to find the most suitable solution for each individual case.The study shows the service life of concrete bridges depends not only on the expert’s knowledge of concrete but also on quality of execution. There is great potential to extend the service life of concrete bridges and to reduce their climate impact. However, it is important that the service life-extending measures also have a low embodied impact.The results of the survey show that technology and cost are the highest priority for mostrespondents, except for researchers where the focus is more on the environment and durability. Many also consider that contractors should set more demands towards environmentally friendly solutions.The results are compiled in the form of recommendations for reduced environmental impact and costs, as well as for how an LCA and LCC can be carried out with regard to service life.</p

A comparative study of the environmental impact of Swedish residential buildings with vacuum insulation panels

A large part of the energy consumption in the European Union member states is related to space heating, a significant share of which is due to transmission losses through the building envelope. Vacuum insulation panels (VIPs), with unique thermal insulation properties, do therefore provide an interesting alternative for the building industry. This paper presents the results of a life cycle analysis (LCA) study that compares the environmental impact of three hypothetical buildings, a standard residential building, a regular well-insulated building and a building insulated with VIPs. The environmental impact includes the global warming potential (GWP) and the primary energy (PE) use, from the material production stage to the building operational phase (50 years). The cradle-to-gate environmental impact categories of ozone depletion potential (ODP), acidification potential (AP) and eutrophication potential (EP) of all building components are also assessed. The study shows a comparatively lower operational energy for the VIP insulated building and a relatively lower total greenhouse gas emission as well as the possibility to save significant living space. The results also show that the VIPs have measurable environmental impact during the product stage while the core material of the VIPs has considerable impact on the results.</p