Discussion of Criteria for Prioritization of Predictive Maintenance of Building Fa?ades: Survey of 30 Experts

The practice of predictive maintenance depends significantly on the diagnosis of in-service performance and on the decision criteria for the selection of maintenance tasks. The definition of these criteria is limited because several actors are involved, each with their own perspectives of performance and maintenance needs. This paper discusses a set of 17 criteria to help the maintenance choice for building fa?ades, from three viewpoints: physical performance, risk, and costs. A group of experts was surveyed and 30 answers were received. Therefore, each criterion will be discussed according to the answers collected. The relative importance (using quantitative weights) and subclasses for each criterion are proposed.     

Tall Building Motion Control Using Double Skin Fa?ades

Double skin fa?ade (DSF) systems are more effective environmental mediators than conventional single skin fa?ade systems, and, due to this reason, their usage for tall buildings has increased despite their higher initial costs. This paper investigates the potential of the DSF system as a structural motion control device in tall buildings regarding dynamic wind loads. The connectors between the inner skins and outer skins of the DSF system are designed to have very low axial stiffness with a damping mechanism so that the dynamic motion of the primary building structure can be reduced. Governing equations are generated for motion of both the primary structures and DSF outer skins and solved to anticipate the dynamic responses of the system. The primary structure motion can be substantially reduced by the low stiffness DSF connector design introduced in this paper. However, the excessive motion of the DSF outer skins is a serious design limitation of the system. Further research is required for the practical application of the proposed system.     

Impact Resistance of Annealed Glass Panels

Annealed glass is by far the most commonly used glazing material in building construction. The resistant properties of glazing panels to wind loading has been studied for a long time based on quasistatic modeling. More recently, the vulnerability of infrastructure and its protection against acts of terrorism has been receiving a great deal of attention, as pioneered by the work of Wu and Hao from within Australia, whereas vulnerability studies by Stewart were specific to glass fa?ades in terrorism scenarios. Emphasis has been on modeling the blast induced pressure and impulses, as they are applied to the panels while the resistant properties of the glazing materials have been based on assumptions used currently in design. Research undertaken by the writers over the past two to three?years have revealed scopes of possible improvements to the current models that have been used in defining the resistant properties of glazing materials. Models based on the well known Weibull distribution, although widely assumed in practice, have been found to be not fully consistent with evidence produced experimentally or by analytical simulations. The interaction of the principal stresses surrounding the crack tip and higher mode effects have also been found to have significant effects on the ultimate behavior of the panel. The accurate modeling of these phenomena is particularly important for large panels. This paper provides an update of the redevelopment of a realistic behavioral model for annealed glazing panels subject to impact action. A new simulation procedure that takes various described phenomena into account is presented in this paper.     

Decision-Support Tool for Assessing the Environmental Effects of Constructing Commercial Buildings

Construction of commercial buildings consumes significant amounts of energy and produces lots of emissions and waste. Where should environmental improvement efforts be focused during design and construction? The Construction Environmental Decision-Support Tool allows designers and industry practitioners to quantify energy use, emissions, and waste generation rates due to the construction phase of commercial buildings. A case study of the Bren School at the University of California, Santa Barbara, and several relevant construction scenarios are analyzed. When considering the complete building over its entire life cycle, the construction phase comprised 2% of energy consumption, 1% of CO2 emissions, 7% of CO emissions, 8% of NOx emissions, 8% of PM10 emissions, and 1% of SO2 emissions. This is due to the dominance of the long-term use phase (50?years) compared to a relatively short construction phase (2?years). Scaling up to the national level, however, construction impacts of projects are significant. In each of the categories studied (temporary materials, equipment and materials transportation, equipment use, waste generation), there are actions that can be taken by designers and builders to improve construction phase environmental effects. In structural frame construction, particular areas of concern include material and equipment selection and temporary material use. Energy use and air emissions are primarily due to equipment use, which accounts for at least 50% of most types of emissions. The major contributors are concrete mixer trucks, concrete pumps, cranes, and air compressors. A single feasible decision, such as using a concrete mixer truck with a 335?hp engine instead of one with a 565?hp engine (but having the same capacity) would reduce total construction energy demand by 12%, and the emissions of CO, NO2, PM10, SO2, CO2, and HC by 3, 12, 8, 10, 12, and 10%, respectively. The use of significantly older equipment can have a formidable effect on construction phase emissions. In general, equipment larger that 175?hp made prior to 1996 tends to have significantly greater emissions of HC, CO, and NO2 than more recent models. The majority of waste generated during construction of the structural frame consists of concrete and wood.     

大型高炉出铁沟用耐火材料的研究与应用

对大型高炉出铁沟用浇注料、捣打料、喷补料的性能进行了研究，分析了材料的性能、施工工艺与使用寿命的关系，认为适当的维护对于降低成本、提高寿命是有益的，铁厂需要合理的考虑使用寿命与材料的价格因素。     

Problem Solving Solutions in Thermal Spray:HSE and Overspray

目前金属基材料的原材料成本对热喷涂涂层的经济性造成压力。特别是材料挥发和近期铼、钨、钴和镍基材料的价格增长,对各应用领域的许多涂层的经济性造成严重威胁。由于沉积效率的限制,喷涂中未沉积物问题变得越来越重要,不仅只是减少浪费,还可以从材料自身价值角度去看。回收是解决这个问题的一个措施,特别是当废料中含有高价值金属时。欧洲执行的REACH(化学制品的注册、评估、授权)将会逐步强制淘汰标有有毒的材料和物质的使用。在热喷涂中使用这些有毒物质或使用热喷涂产品可能暂时是安全的,然而,从法律限制和从其他工业领域得到的指示表明,像WC-Co粉末这样的化学制品对人体有害。要想在将来的涂层工厂中保持竞争性,必须符合不断提高的更严格的环保和安全规程。     

Computer-Integrated System for Estimating the Costs of Building Projects

The cost estimate is considered one of the most important and critical phases of a construction project. Preparing reliable and accurate estimates to help decision makers is the most challenging assignment that cost engineers and estimators face. For decades, practitioners in the construction industry focused only on estimating the initial cost of a facility, neglecting costs associated with operating and maintaining it. Today, more interest lies in investigating the economics of facility management, which include the cost of owning and operating a building over its useful life. This paper presents a methodology that can be used for an integrated conceptual cost estimating and life-cycle cost analysis for construction projects during their initial phase. The methodology describes the development and implementation of a system that automates the preparation of parametric cost estimates and forecasts future running costs of building projects. The system integrates relational databases, a parametric cost estimate module, an AutoCAD module, a global module, a cost estimate forecasting and decision support system module, and a life cycle costing and sensitivity analysis module. The system will automatically generate a new parametric estimate upon any modification in building design. Once the capital costs are identified, the system forecasts the cost of running and maintaining the new building throughout its expected service life. After assigning the range of deviation, a sensitivity analysis is conducted, which identifies the most sensitive parameters for further consideration and analysis. Designing the system in a user-friendly environment allows owners and decision makers to envision the feasibility of new building projects within their anticipated life cycles. Moreover, it assists architects and cost engineers in generating parametric cost estimates in a dynamic environment. A numerical case example is presented to illustrate the usefulness and capabilities of the developed system.     

Selecting Cost-Effective Green Building Products: BEES Approach

The Building for Environmental and Economic Sustainability (BEES) tool implements a rational, systematic technique for selecting cost-effective green building products. The technique is based on consensus standards and designed to be practical, flexible, and transparent. The Windows-based decision support software, aimed at designers, builders, and product manufacturers, includes actual environmental and economic performance data for 24 building products across a range of functional applications. BEES measures the environmental performance of building products using the environmental life-cycle assessment approach specified in the latest versions of ISO 14000 draft standards. The approach is based on the belief that all stages in the life of a product generate environmental impacts and must be analyzed. The stages include raw material acquisition, manufacture, transportation, installation, use, and waste management. Economic performance is measured using the ASTM standard life-cycle cost method. The technique includes the costs over a given study period of initial investment, replacement, operation, maintenance and repair, and disposal. Environmental and economic performance are combined into an overall performance measure using the ASTM standard for multiattribute decision analysis.     

宝钢3号高炉长寿设计与操作维护实践

宝钢3号高炉1994年9月20日投产,至今已稳定运行了18年,创造了多项宝钢高炉技术经济指标纪录和国内最长寿高炉记录。经过多年来的探索与实践,形成了具有3号高炉自身特点的长寿设计和操作维护综合技术。主要长寿措施：合理的炉型和冷却系统设计;强化入炉原燃料质量管理,优化操业配置,确保炉况稳定顺行;保证足够的冷却强度、改善并稳定纯水水质;采取安装微型冷却器、硬质压入、人工造壁、更换破损冷却壁、稳定铁口深度、适当压浆、完善炉缸监控等多种长寿维护措施,确保炉体炉缸状态良好,从而有效延长高炉寿命。     

Budgeting for Facility Maintenance and Repair. II: Multicriteria Process for Model Selection

The second of two in a series, this paper presents an objective process for selecting an appropriate model for facility maintenance and repair budgeting. Three model evaluation criteria relating facility attributes to maintenance and repair costs—consideration of the facility's physical characteristics and environment, building system and component life cycles, and penalty costs brought on by deferral of maintenance—are introduced. The expense of supplying the necessary data for a model's implementation, given the model user's existing database, is presented as a fourth evaluation criterion. The relative merits of 18 available budgeting models are then assessed against these criteria using various multicriteria decision-making tools: Analysis of dominance, with results displayed via a Hasse diagram; lexicographic ordering; and the technique for order preference by similarity to ideal solution. The results of the evaluation demonstrate how the preferred alternative can change in response to a decision-maker's priorities. Conversely, the selection process can provide considerable insight into these models with very little knowledge about the value system or philosophy of the model users and the decision makers.     

Roofing Materials’ Contributions to Storm-Water Runoff Pollution

Development in sensitive watersheds continues to pose environmental problems for receiving waters. One contributor to this long-term pollution is building and other construction materials. However, the long-term effect of many building materials on the environment has not been quantified due to limited testing of these materials prior to sales and installation. Laboratory “leach” testing of commercially available roofing materials by this research group indicated that the potential for release (primarily nutrients, lighter hydrocarbons, pesticides, and metals) is substantial. Testing of metals’ release from aged roofing panels also has shown that the potential for pollutant release still exists after 60?years. The data missing from a complete evaluation of many roofing materials is behavior over the lifespan of the material, including the critical period of initial exposure. The 2?years of runoff data from a pilot-scale testing of these materials indicated substantial concerns regarding zinc from uncoated galvanized metals and copper from treated woods in this early part of the materials’ lifespan, plus the potential for long-term nutrient releases in the runoff from several roofing types.     

Interstitial Space Design in Modern Laboratories

Modern laboratory design and construction is becoming increasingly complex with advancements in mechanical, electrical, plumbing, and specialty system technologies. Laboratory projects often have critical schedules and rigorous maintenance and operations requirements. The use of interstitial spaces that create additional floors for mechanical systems is a design strategy that can facilitate both the construction and operation of laboratories. By providing additional space and easier access to mechanical systems, interstitial designs facilitate maintenance and reconfiguration of laboratories, thus reducing life cycle costs. Despite these and other advantages, the use of interstitial space is often eliminated as a laboratory design option due to perceptions of high first costs. This paper presents an analysis of the advantages and disadvantages of interstitial space design as an alternative to traditional plenum construction. The opinions of experienced operators, designers and builders of interstitial building spaces are presented. Survey results of design and construction professionals are presented illustrating current perceptions (and misconceptions) of interstitial spaces as a design alternative for laboratories. Finally, a detailed interdisciplinary case study redesign is used to illustrate the comprehensive effects of introducing an interstitial space design in an actual modern laboratory in which a 1.6-year payback was achieved on the investment in an interstitial design alternative. The research concludes increased first costs can potentially be offset by savings in construction time, and that valuable savings in maintenance and operation costs help to justify the use of interstitial space design solutions.     

Designing Buildings for Maintenance: Designers' Perspective

The degree to which the design of a building embraces maintenance considerations has a major impact on its performance. A survey was conducted of the largest 211 building design firms in the United States to investigate the relationship between design practices and maintenance considerations. The findings shed light on the extent to which maintenance issues are considered when designers specify building materials and service equipment; the level of designers' knowledge in maintenance-related issues; the degree to which design personnel is exposed to training in maintenance-related matters; the extent to which designers consult property managers and maintenance consultants; the relative importance of maintenance issues to other design factors; the level of difficulty in cleaning, inspecting, repairing, and replacing various building components; and the magnitude and frequency of maintenance-related complaints that designers receive from clients and tenants. The performance of buildings is likely to be enhanced if designers are cognizant of maintenance-related matters.     

搅拌摩擦焊用钨铼合金的研究进展

搅拌摩擦焊接技术是一种环保、低成本的固相连接技术,已经在航空航天、轨道交通和新能源汽车等领域得到广泛应用。对于高熔点合金材料如钛合金和不锈钢的搅拌摩擦焊接而言,搅拌头材料成了主要制约因素。钨铼（W-Re）合金凭借其高熔点、高硬度和强抗腐蚀性等优点,已成为研究和应用最热的搅拌摩擦焊接高熔点合金的搅拌头材料。本文综述了近年来在搅拌摩擦焊工艺中以W-Re合金作为搅拌头材料的制备方法、复合强化技术和应用场景的研究进展。此外,还展望了拓宽W-Re合金在搅拌摩擦焊领域应用的前景,包括降低W-Re合金的生产成本和提高其服役寿命等方面,旨在推动W-Re合金搅拌头材料在搅拌摩擦焊领域的进一步应用和发展。     

武钢8号高炉强化冶炼条件下的长寿实践

武钢8号高炉投产4年多来,实现了高利用系数下的长期稳定顺行、冷却壁零破损。就8号高炉如何解决强化冶炼与高炉长寿这一矛盾进行了较为全面的分析,通过加强原、燃料管理,优化入炉配料结构,调整装料制度,稳定热制度及造渣制度,提高炉型维护意识等,实现了强化冶炼条件下的长寿生产。     

Medical Records for Building Health Management

Medical records provide essential information for evaluating a patient’s health. Without them, it would be difficult for doctors to make accurate diagnoses. Similar to diagnoses in medical science, building health management also requires building medical records for making accurate diagnoses. At later stages of a building’s life cycle, when the budget is limited, organizations responsible for building repairs and maintenance are unable to digitalize building health diagnoses and keep complete medical records of buildings; as a result, maintenance crews usually cannot fully understand buildings’ overall health conditions and their medical histories, which may result in erroneous diagnoses directly or public safety dangers indirectly. Using the problem-oriented medical record adopted for the medical diagnosis of human diseases, this paper designs a building medical record (BMR), which allows simple electronic archiving, and evaluates its practicability with a case study of school buildings. The purpose of a BMR is to enable maintenance engineers (building doctors), building managers, and contractors of school buildings to have low-cost access to required information for making complete evaluations and maintenance suggestions for buildings.     

Computer-Aided Healthcare Facility Management

The decision-making process in the field of health-care facility management is multifaceted and encompasses many different areas, including maintenance, performance, risk, operations, and development. Information and communications technologies are perceived as the interface that integrates these topics. The main objective of this research is to develop a decision-support system based on core parameters affecting the performance of health-care facilities. This paper presents the preliminary development of a quantitative integrated health-care facility management model, subdivided into the following three interfaces: input, reasoning evaluator and predictor, and output. The model proposes the following five modules: maintenance, performance and risk, energy and operations, business management, and development. It offers projection of maintenance costs, performance, and risk of built facilities in the health-care sector. The model hypotheses are that age, occupancy, and environment affect the maintenance of the facility. These factors are quantitatively developed and analyzed for performance-based maintenance planning, employing an occupancy coefficient and a projection of performance indicator. Simulations of the facility coefficient for different combinations of occupancy and environment reveal that the occupancy level is a major factor that causes an augmentation of more than 18% in the allocation of resources for maintenance compared with standard occupancy. Prediction of the performance score of a building is carried out using a nonlinear pattern for the structural components and linear patterns for the rest of the components.     

Service Life Assessment of Existing Highway Bridges with No Planned Regular Inspections

Safety of a highway infrastructure system depends very much on the proper maintenance of bridges. The level of required maintenance is, typically, determined through a series of regular field inspections with the guidance of safety–economy trade-off. In Turkey, bridge maintenance, repair, and rehabilitation are currently performed on an as-needed basis. Time-dependent reliability analysis cannot be utilized for Turkish bridges for the time being since the majority of the bridges are either not regularly inspected or not inspected at all. The purpose of this paper is to propose a simple method to assess the remaining service life of a bridge by defining a relationship between its current condition rating and its age by evaluating a set of bridges at different ages. In a case study, 28 bridges were inspected for the first time to assess the average life expectancy. The average life of a bridge was predicted to be 80?years, and for this set of bridges, the main body components were found to deteriorate more than earth retaining and serviceability components.     

Health and environmental benefits from air pollution reductions in Hungary

The aim of this study was to assess the cost and benefit of the implementation of a specific energy saving program in Hungary. We have considered the possible reduced damage to public health, building materials and agricultural crops that may be obtained from reducing emissions of important air pollutants and also how the program contributes to reduced emissions of greenhouse gases. The measures are described in the National Energy Efficiency Improvement and Energy Conservation Programs (NEEIECP), elaborated by the Hungarian Ministry of Industry and Trade and accepted by the Government in 1994. The energy saving expected from the program is approximately 64 PJ/year. The benefits were estimated using monitoring data and population/recipient data from urban and rural areas in Hungary together with exposure-response functions and valuation estimates mainly from western studies. Our analysis indicates that the main benefit from reducing the concentrations of pollutants relates to public health and that reduced prevalence of chronic respiratory diseases is an important effect. Reduced premature mortality is also important and the estimated attributable risk of air pollution to excess mortality at present is approximately 6%. The estimated annual benefit of improved health conditions alone is likely to exceed the investments needed to implement the program. In addition there are significant benefits due to reduced replacement and maintenance costs for building materials (30-35 million US$ annually in Budapest only). The damage to crops due to ozone is large, but a significant improvement in Hungary depends upon concerted actions in several countries.