经典外文翻译两篇,中英对照

外文原文 1Building Materials Selection and SpecificationFae'q A. A. RadwanFaculty of Engineering, Near East University, KKTC, Lefkosa, Mersin 10, TurkeyAbstract: The limitations in the selection of the building materials and to the sustainability of any building construction materials that can be used are presented. The practices and techniques that can be used in reducing and minimizing the environmental impacts of building are discussed. Recommendations of using secondary and recycled materials in the construction of buildings are given. Framework for methods of assessment of the sustainability in building construction for environmental performance is presented.Key Words: Limitations, sustainability, environmental impacts, framework, climate.1. IntroductionThere is an apparently unbounded range of possibilities for the selection of building materials for the construction of structures of almost any shape or stature. Its quality will affect the structure function and long life, and requirements may differ with climate, soil, site size, and with the experience and knowledge of the designer. The factors that have the most outstanding solutions are impermeability, control of heat, air, and water flow, and the stability of the structure [1-3].Raw materials extraction, manufacturing processes, and the transportation of the materials to the project site have a multitude of impacts on the environment. These include the disruption of habitats and ecological systems, use of water, and, through energy use, the emissions of air pollutants and climate change gases. Building materials also have major impacts on the building occupants manufacture, construction of buildings and the use of building materials make a significant environmental impact internally, locally and globally. But it is not easy to deliver information to make adequate inclusion decisions considering the whole life cycle of a building. Decisions on sustainable building integrate a number of strategies during the design, construction and operation of building projects. Selection of sustainable building materials represents an important strategy in the design of a building.2.SustainabilityIn recent years, the concept of sustainability has been the subject of much disputation by academics and professionals alike. In 1987, the World Conference on Environment and Development defined sustainable development as development that meets the needs of the present without compromising the ability of future generations to meet their own needs (WCED, 1987).Sustainability must address ecological impacts, regardless of conflicting interpretations of the WCED definition.A good sustainable product must give as much satisfaction as possible for the user. If not, it will be unsuccessful on the market and an economic failure.It is also important to inform people as to what basis a certain product is considered to be sustainable or not and why they should buy it [4- 5].When developing a new product, it is illustrative to move between the three corners Ecology, Equity and Economy in order to obtain a suitable balance so that each category can be fulfilled in the best way.·Ecology (environmental protection).·Equity (social equity).·Economy (economic growth).2.1 Materials Selection and SustainabilityAmong the notable technological developments of the 20th century has been the development of tens of thousands of new materials for use in construction and engineering. The construction industry has also grown to the point where it is a very large consumer of energy and materials. Concern for the environment and the impact of human activity on the Earth's ecological systems has now become clear sighted.We are faced with the problems of material selection and the environmental consequences of their use. Environmentalists have proposed various methods for assessing the impact of materials and energy use, these include ecological foot printing, ecological rucksacks, embodied energy and carbon dioxide values, and so on. Engineers have put forward rational selection methods for the choice of materials. These techniques will be reviewed and explored in an attempt to provide an environmentally-aware, materials selection method- logy for use in construction.Strictly, the term sustainable means that something is capable of being sustained not for an hour, or a day, or a week, month or year, but indefinitely.The implication is that if some process which uses materials and energy is described as sustainable, then the materials and energy which are consumed arecapable of being replaced by natural or other processes as fast as they are consumed. In many cases materials and energy appear to be consumed at a faster rate than they are being replaced. However, to make a judgment, we would need to know what the respective supply and consumption rates are in other words we need some quantitative or numerical index to help us [2].2.2 Environmental CriteriaSince construction uses such large quantities of materials, it has a major impact on the environment. In order to assess and evaluate such impact, a number of criteria or indices have been devised by economists, engineers and environmentalists, and the more important of these are the following [2].2.2.1 Embodied EnergyThis is quite simply the amount of energy consumed in manufacturing a unit quantity of a material, and it is usually expressed in kJ/kg. Its value is determined by the efficiency of the manufacturing plant. Values range from 275 GJ/tonne for aluminum (a high value) to 0.1 GJ/tonne for gravel aggregates (a low value) [2].2.2.2 Embodied Carbon DioxideEmbodied C02 is similar to embodied energy. It is the weight of C02 emitted during manufacture of unit weight of the material, and is usually expressed as kg of C02 per ton.Again, the value will depend upon the efficiency of the manufacturing plant [2].2.2.3 Ecological RucksackThe ecological rucksack concept was devised as a way of assessing material efficiency by F. Schmidt一Bleek [6]. He recognized that many tonnes of raw material could be extracted and processed to make just one kilogram of material. For example, the environmental rucksack for the precious metal platinum is 250,000:1.2.3 Rational Selection MethodThere are various approaches to the problem of selecting materials from the huge numbers now available. Designers can have recourse to materials property charts and data books. Alternatively, they can talk to their colleagues, hoping that by widening the knowledge circle, they will not omit a significant group of materials. Another strategy is simply to specify the same or a similar material to those used in previous, similar designs. All these are valid approaches, but they may result in the specification of a less than ideal material and overall, a less than optimal solution to the problem [3-5].The basis of the rational selection methods devised to date is a recognition that the performance of a component, artifact or structure is limited by the properties of the materials from which it is made. It will be rare for the performance of the item to depend solely on one material property; in nearly all cases, it is a combination of properties, which is important. To give an example, in lightweight design, strength to weight ratio of, and stiffness to weight ratio E/pwill be important. Ref. [3] has put forward the idea of plotting material properties against each other to produce material property maps. On these maps, each class of material occupies a field in material property space, and sub-fields map the space occupied by individual materials.These materials property charts are very information-rich they carry a large amount of information in a compact but accessible form. Interestingly, they reveal correlations between material properties, which can help in checking and estimating data, and they can also be used in performance optimization, in a manner such as that set out as follow.If we consider the complete range of materials, it immediately becomes apparent that for each property of an engineering material there is a characteristic range of values, and this range can be very large. For example, consider stiffness (Young's Modulus E). Materials range from jelly (very low stiffness) up to diamond (very high stiffness). The properties can span five decades (orders of magnitude),A number of conclusions can be drawn, including:(1) A rational selection method such the one put forward by Ashby is capable of incorporating environmental parameters such as embodied energy and C02 or the environmental rucksack concepts, thereby making possible rational selections based on environmental considerations.(2) This method is not as simple to use as the environmental preference method or the environmental profiles method. However, this rational method could be used to generate data for the environmental profiles and preference methods.(3) The construction industry needs to take steps to better integrate itself into the materials cycle. The quantity of demolition waste needs to be reduced, and more of it should be recycled. To this end, the building designers need to keep full records of materials of construction, and buildings need to be designed for easy dismantling at the end of their useful lives.2. 4 Ashby's Materials Selection MethodologyMaterials selection charts一Property interaction (not always causal)一First order optimization●Performance indices●Multiple constrains●Multiple design goals●Shape and material interaction一“Enhanced" performance indicesProcess selection [3, 4].3. Foundations and Construction ComponentIn any consideration of which building materials and alternatives can feasibly be integrated into the foundations of a large-scale development there are several limitations that must be considered.In terms of the actual materials that may be used, there are three main limitations. First, because of the large scale and heavy loads that the foundations must support, strength is imperative. Any materials must be consistently strong and able to effectively distribute the weight of the structure. The second major limitation is climate. In areas with sub-zero winter conditions, frost heave is a major consideration. For this reason, foundations must be deep enough to support the structure despite any changes in near-surface volume; shallow foundations will be insufficient unless certain innovative steps are taken. The limitation of climate also influences any decision on insulating foundations. Finally, there is the consideration of cost. This consideration is reliant on material availability, cost per unit, and building techniques and associated labor. For these reasons, the only materials that can feasibly be used are concrete and steel. Therefore, the alternatives for minimizing impact lie more in the methods of construction and any realistic structural changes that can be made.The three main foundation components of concrete, steel, and insulation will be examined as the only reasonable materials for the construction of a building with limitations such as the foundations [1].3.1 ConcreteIt is the fundamental component of the foundation construction, receiving the building loads through walls or posts and distributes them down and outwards through the footings. Concrete and cement have ecological advantages which include durability, long life, heat storage capability, and (in general) chemical inertness [8].The life cycle concerns of concrete are as follows. First, there is land and habitat loss from mining activities. Furthermore, the quality of both air and water quality suffer from the acquisition, transportation, and manufacture. Carbon dioxide emissions are also a negative environmental impact accrued through the production and use of concrete. Similarly, dust and particulate are emitted at most stages of the concrete life-cycle. $oth carbon dioxide and particulate matter have negative impacts on air quality [1]. Water pollution is also another concern associated with the production of concrete at the production phase. Fly ash is by-product of the energy production from coal-fired plants and increasing its proportion in cement is environmentally beneficial in two ways. First, it helps in reducing the amount of solid waste which requires disposal. As well, fly ash in the cement mixture reduced the overall energy use by changing the consistency of the concrete. Fly ash, increases concrete strength, improves sulfate foundation, decreases permeability, reduced the water ratio required, and improves the pump ability and workability of the concrete [9]. Now in the United States, the Environmental Protection Agency requires that all buildings that receive federa funding contain fly ash and most concrete producer: have access to this industrial waste [9].There are alternative methods of both making concrete and building foundations with this concrete that have environmental benefits, no matter the structure scale or climate. These include Autoclaved Aerated Concrete, the increased integration of fly ash into the cement mixture, and the use of pre-cast foundation systems to reduce resource use. Through consideration and possible integration of these alternatives, impacts could potentially be reduced.3.2 SteelAs wood resources are becoming limited, steel is increasingly popular with builders. In the case of a large-scale building, steel reinforcement is basically a necessity for overall strength and weight distribution.The initial life cycle impacts of steel use are similar to those of concrete. These include land and habitat loss from mining activities, and air and water quality degradation from materials acquisition and manufacture [1]. However, the largest proportion of steel used nowadays contains a percentage of recycled materials. In terms of improving environmental conditions by reducing impacts, this is the only real recommendation for the use of steel in building foundations; to purchase recycled steel products. Not only would this reduce industrial and commercial solid waste,such a decision would also reward the manufacturers of such products.3. 3 InsulationNew and innovative pre-cast building foundations are becoming increasingly available and feasible for implementation. These new systems can reduce the overall raw material use, as well as conserve energy through the creation of an efficient building envelope. A further used of this rigid insulation as a skirt around the building foundations helps to eliminate any potential frost problems, improve drainage, and help further reduce heat loss. A polyethylene air and water vapor barrier is applied above the insulating layer, as is a three to four inch layer of sand. These shallow foundation systems have excellent insulating properties, decreased use of raw materials for concrete, and comparatively low demands for labor. However, the use of rigid insulation is increased. Also, in soils where frost and drainage is a consideration additional piles in the centre of the foundation may be required to prevent movement. This increases the relative land disturbance, although it remains still much less than that of deep foundation systems. Shallow foundations are structurally sound and are becoming increasingly common in colder climates. There are strength considerations associated with these new techniques which must be addressed by someone with the technical ability to do so, before they can be feasibly recommended for the building of the new residence.As discussed above, there are limitations to the sustainability of any foundation construction materials used. In other words, there are environmental impacts associated with all types of foundations. For these reasons, a primary recommendation is the use of secondary materials (fly ash and recycled steel) in the construction of foundations.4. FrameworkThe material components of the building envelope, that is, the foundation, wall construction, insulation and roof, have been analyzed within a framework of primarily qualitative criteria that aim to evaluate the sustainability of alternate materials relative to the materials cited in the current foundation design. This analytical process has enabled the identification of several construction materials that can be feasibly integrated into current design and construction standards of the building envelope.The tools and strategies described below are useful in analyzing the relative benefits of different materials[9-14].Life-Cycle Assessment (LCA). LCA is a comprehensive analysis that takes intoconsideration all aspects of a material over its entire lifetime: raw materials extraction; manufacturing and processing; transport; use; and post-use recycling, reuse, or disposal. This approach enables a true "apples to apples" comparison between materials.The BEES system (Building for Environmental and Economic Sustainability) developed by the National Institute of Standards and Technology is the most widely used methodology. BEES provides materials with a score that can be compared to other similar products. At this time, however, a fairly limited number of materials have completed the BEES analysis.Life-Cycle Costing. Life-Cycle Costing is an analysis of the short- and long-term costs associated with a material, from purchase to ultimate recycling or disposal. This includes frequency of replacement, maintenance costs, and costs that are avoided through use of the material (or system). LCC is useful in looking beyond a comparison based solely on first costs. Similar to LCA, this type of analysis is not available for all materials, but a back-of-the-envelope calculation is usually fairly easy to work up.Certification. Many conventional building products are approved or certified by independent third party or government groups. The Forest Stewardship Council certifies the certifiers (Smart Wood and SCS) that assess whether forestry companies are using sustainable management practices to harvest wood. The Carpet and Rug Institute provides a Green Label for carpets that meet certain low-VOC criteria. Green Guard certifies products that meet strict indoor air quality criteria. The Department of Energy's Energy Star label identifies equipment and appliances that meet or exceed standards for energy efficiency. Scientific Certification Systems and Green Seal certify recycled-content claims and other green product claims made by manufacturers.5. ConclusionOver-consumption, resource utilization, pollution and over-population are examples of the perhaps most basic problems for the environment in the future. A more sustainable future can be achieved by producing more sustainable products causing less environmental impact. Materials and design are and will always be very important areas when developing more sustainable products.The Life Cycle Assessment concept might be the most effective way of determining the environmental impacts for all product stages from extract of material to the product disposal stage. A price must be set for restoration on everyenvironmental impact. Information can be received from official authorities pertaining to the environment in different countries. Renewable and easy recyclable materials are preferably used together with a design for easy recycling and repair of the products. Minimization of the energy connected to the product is also important. Full sustainability can never be achieved for products according to thermodynamic laws. However, the attempt to achieve more sustainability is a requisite if we want to preserve the earth for the coming generations. Education, research and spreading of information will be very important for the future in order to receive more sustainable products especially because the market demand is important in order to develop successful sustainable products.References[1] M. Davison, J. Persmann, J. Reid, J. Stange and T. Weins, Green BuildingMaterials Residence, A WATgreen/ERS 285 study.[2] J. L. Sturges, Construction Materials Selection and Sustainability, School of theBuilt Environment, Leeds Metropolitan University, UK.[3] M. F. Ashby, Materials Selection in Mechanical Design, Pergamon, Oxford, 1992.[4] M. F. Ashby and K. Johnson, Materials and Design: The Art And Science ofMaterials Selection in Product Design, Oxford: Butterworth-Heinemann, 2002 [5] L. Y. Ljungberg, Materials selection and design for development of sustainableproducts, Materials and Design 28(2007)466-479.[6] F. Berkhout and D. Smith, Products and the environment: an integrated approachto policy, Eur. Environ 9 (1999)174-185.[7] F. Schmidt-Bleek, Carnoules Declaration of the FactorTen Club, WuppertalInstitute, Germany, 1994.[8] A．Wilson，Building green on a budget,Environmental Building News8(5)(1999)．[9] G．E．Dieter，Engineering Design，McGraw-Hill，New York，l991．[10] Sandy Patience (Ed．)，The Role of Evidence in The Selection of BuildingProducts and Materials，Constructing Excellence in The Built Environment．[11] M．D．Bovea and R．Vidal，Increasing product value by integrating environmentalimpacts costs and customer valuation，J Resour Conserv Recycling 41(2004) 133-145．[12] N．S．Ermolaeva,M．B．G．Castro and P．V．Kandachar, Materials selectionfor an automotive structure by integrating structural optimization with environmental impact assessment，Materials and Design 25 (2004) 689．698．[13] M．Goedkoop and R．Spiensma，The Eco-Indicator 99：A Dam age OrientedMethod for Life Cycle Impact Assessment，Amersfooft：PRe consultant B．V．，2000．中文翻译 1建材选择和规格Fae'q A. A. RadwanFaculty of Engineering, Near East University, KKTC, Lefkosa, Mersin 10, Turkey摘要：建材选择的限制和可利用的任何建筑物工程材料的持久性显现出来。