ICSDC 2011: Integrating Sustainability Practices in the Construction Industry

Construction processes are highly energy-intensive and account for a large share of carbon emissions. Construction stakeholders increasingly need to voluntarily measure and publicly report their carbon emissions from large-scale construction projects. This paper will present a framework to assess carbon emissions and carbon reduction opportunities in large-scale construction projects. It therefore will discuss various strategies to quantify emissions in the planning phase of construction projects and to verify carbon emissions in order to provide guidelines for stakeholders. In addition, the quantification scope for construction projects and the impact of different scope definitions are discussed. The presented framework will facilitate construction stakeholders in internally identifying and mitigating the carbon-related risks caused by their construction projects. It also will facilitate their participation in voluntary GHG reporting and reduction programs.

The Intergovernmental Panel on Climate Change (IPCC) claimed that greenhouse gases generate impact large enough to change global climate. Some industries are beginning to reduce carbon emissions from their designs and manufacturing processes in order to comply with IPCC recommendations around the world. According to statistics, the construction industry generates the greatest environmental impacts among all the other industries. Green building designs and standards are developed to improve building operation energy and embodied energy efficiencies, and minimize energy and wastes. The most common approach for green building certifications is to rate the compliance of each green building standard through a point rating system. No green building system has yet correlated its rating to the level of "greenness" of buildings. The level of certification does not reflect corresponding reduction in environmental impact and carbon emission. This paper establishes the framework to correlate green building standards with equivalent carbon emissions by, first, reviews the criteria of direct and indirect carbon emission measurement, second, identifies the focal point of carbon emission modeling, and finally, identifies the variables for carbon emission modeling of buildings.

Climate change concerns, pending regulations, and potential legislation have made federal agencies begin to consider their carbon footprints in planning and policies. In the future, the state of Kansas may have to report and account for its carbon footprint and propose solutions to reduce greenhouse gas emissions by conserving energy and water. As a large state agency, the carbon footprint of the Kansas Department of Transportation (KDOT) is a major contributor to the Kansas state government carbon footprint. A research project was begun in 2010 to establish a baseline carbon use footprint for KDOT. Establishing a Carbon baseline for KDOT assets involves three essential steps that include data collection, data assumptions and conversion to carbon equivalents for many facets of DOT operations, including the electrical, natural gas, and potable water use. Utility data was collected for the DOT engineering, maintenance, and operations facilities. This paper documents the methods used and challenges for collecting and establishing the utility energy and carbon footprint for a large organization with hundreds of facilities, along with the carbon footprint calculation methods used.

In the past decades, urban heat island (UHI) phenomenon in the city and its corresponding issues including the mitigation methods have become the main research topics in the area of urban climatology. Researchers have conducted various investigations and measurements in which as the results, they have come out with various prediction models for different purposes. Nevertheless, these prediction models are too complicated for educated non-scientists, in this case the urban planners. At the end, these models remain in the academic domain, unless the scientists are engaged and involve in the urban planning process. There is a gap between scientists and planners. The Screening Tool for Estate Environment Evaluation (STEVE) has been developed as an effort to bridge between urban climatology research, in this case the urban temperature, and urban planning process. In the near future, the STEVE Tool will become an interactive design tool where the urban planners design the building massing and do the urban temperature prediction at the same platform and time. This paper also discusses the prospective of urban climatic analysis tool that lies on how to analyze the interaction between buildings and their surrounding environments as an integrated urban design process.

Buildings have time-varying interactions with local climate condition for its heating or cooling systems; changes on the surrounding climate condition affects building energy consumption. Building envelope therefore plays a critical role in reducing heat gained/ lost, thus energy consumption. Singapore's building regulations currently requires new residential buildings to have a minimum envelope thermal transfer value of 25 W/m² base on the Residential Envelope Transmittance Value (RETV) formula. However, as ambient temperature continues rising with global warming, buildings designed under these criteria might be affected in terms of thermal performance. This paper presents the potential impacts of climate change on building energy consumption, in terms of RETV parameter. Existing local weather data is modified using CCWorldWeatherGen, and entered into TAS building energy simulation. Results showed that there is an increase in building energy consumption of 54% and 75% in 2080 for point and slab block respectively. Hence, current RETV regulations may have to be revised in the future.

The operation, maintenance, and construction of buildings require a huge amount of energy and generate a significant amount of greenhouse gases (GHG's) (Hendrickson 2000). The energy and GHG's are generated from the process of extracting raw materials, producing and manufacturing new materials, transporting materials to sites, and installing materials (Junnila et al. 2006). Energy conservation and control of GHG's are critical to ensure energy security for future generations and to alleviate the impact of climate change. This paper presents a new approach of Enterprise Carbon Accounting. The method is based on categorization depending on the size of the organization and its assets. Categorization of similar buildings and assets are averaged and analyzed as a unit. Outliers and averages of each type are then examined for causes, correlations, and future solutions. The proposed method will establish a carbon emission and energy use baseline for the large scale agency.

This study investigated rammed earth (RE) housing as an alternative to the current method wood frame (SB) used in residential construction in Northern Colorado (NoCO). Using an embedded methodology including; direct observations, archival records, and documentation to produce the findings. The objectives of this research evaluated the energy consumption by both RE & SB housing. RE is purported to be more energy efficient because of the thermal dynamics of wall construction. The claims, by proponents of RE indicate residents can save between 30–50% on energy consumption. This study substantiates that RE can conserve on energy consumption, however the percentages were lower. This is a comparative analysis rather than a definitive choice of prototypes.

Reducing energy usage, or at least controlling energy consumption, is an important goal for Colorado Housing Authorities (CHAs). Observational data, however, suggests only a limited number of CHAs have undertaken energy conservation measures. Data to either support or refute these observations is not avaliable, yet it is needed by funding agencies seeking to enhance energy conservation through their grant programs. This paper reviews the need for and the development of a survey of the application of green building technologies in both the maintenance and construction of CHAs' properties. Data collected will ultimately assist funding agencies in identifying current levels of technology implementation among CHAs as a planning tool for current and future energy projects.

From the beginning of the operation of the Olympic Pool in Tennessee, there were signs of trouble, such as liner bubbles, cloudy water, differential gutter rim level, sand in the bottom of the pool, and dirty filter bags. After eight months of operation, sand could be seen coming out of the inlets and one blister, located approximately in the middle of the pool rose above the water and finally the pool liner tore. In determining the causes of the problem, the subgrade subsidence, pool wall settlement and distortion, and sub-floor pipe damage were considered in this investigation. Laboratory testing and subsurface investigations were performed. In this investigation, the mechanism of the failure and the reasons behind the liner bubble were explored and discussed. As described in the paper, it appears that significant fracturing of the sub-floor plumbing due to compression of under-compacted fill caused pipe failure. Knowing the mechanism of the failure helped to sustain the pool and keep it operational.

Aiming to be "City in a Garden", greenery systems are widely developed to be integrated into buildings in Singapore. Zero Energy Building of Singapore as a test bed for several green building technologies also tested the greenery systems. Vertical greenery systems and extensive rooftop greenery systems were installed and the thermal performance was being monitored. The paper discussed on the performance of the greenery systems in reducing heat gain into the building and cooling down the ambient air temperature. The study was conducted by field measurement of the surface temperature and the ambient air temperature. The study showed that there was significant reduction on the surface temperature of the wall/ roof being shaded by the greenery systems up to 11°C for the vertical greenery on the west façade, 6.6°C for the vertical greenery on the south façade and 24.5°C for the rooftop greenery; and on the ambient air temperature at 300mm away from the external bare wall/roof and greenery of up to 3°C for the west facing vertical greenery, 2°C for the south facing vertical greenery and 7°C for the rooftop greenery.

Water features, within an urban area have a positive effect on the microclimate of the surrounding areas when natural cooling from evaporative process is needed in the hot sunny day. The increased availability of water usually enhances evaporation, and the associated uptake of latent heat provides and additional daytime cooling effect. The water bodies of the river operate as the cooling source on the microclimate of the surrounding area. Air temperature near or over bodies of water is much different from that over land due to differences in the way water heat and cool. Water bodies are noted to be about the best absorbers of radiation, but on the other hand, they exhibit very little thermal response. Many other researches argued that evaporative cooling from water bodies or water features is yet one of the most efficient ways of passive cooling for building and urban spaces. However, evaporative cooling may not work optimally in a hot humid tropical country due to its relatively high humidity. This paper studies the evaporative cooling performance of a waterway of approximately 70m to its surrounding micro-climate. The waterway is situated in Kallang, Singapore. The air temperature and relative humidity are measured continuously for five months, May and September 2010, to find the clear extent of the cooling effect from the waterway horizontally. There is a total of 10 measurement points in each location, where five points of measurement are located along the waterway and another five points of measurement are located moving away from the waterway in order to observe the extent of its cooling effect.

Zero Energy Building (ZEB) of Building and Construction Authority (BCA) in Singapore is a retrofitted building with different green building design features and technologies. It is used as a test-bed for innovative building designs and energy efficient building solutions, particularly for existing buildings. The study focused on the performance of shading devices and lightshelves in providing daylighting and affecting the thermal comfort in naturally ventilated classrooms under afternoon sun. Field physical measurements were conducted to compare the space with and without the passive design elements. For the shading devices, the complete setting configuration showed higher mean radiant temperature reduction of around 1°C – 2°C. The illuminance level of the complete setting configuration showed around 100 lux more reduction than the 4-panel configuration. For the lightshelves, the reflective surface improved about 100 lux at 1pm and did not improve much afterward. The mean radiant temperature showed a lag of half an hour. The zone with the reflective surface was heated up earlier and in overall, the temperature was increased of around 1°C deeper in the room.

Contractors are working towards defining their role in the movement towards sustainability in the built environment. Amongst all of the uncertainty surrounding this quest, one thing is certain: solutions must be based upon sound financial principles. Transportation during the construction process has been identified as one area where the environmental impacts of construction may be reduced. Compressed natural gas is an alternative fuel that could be used in concrete mixer trucks to increase the environmental performance of the construction process. The question is: will switching from diesel fuel to compressed natural gas save money while providing increased value during the construction process? This research examines the various costs, impacts, and savings involved in such a transition. Results of the study indicate the cost is a function of numerous operational parameters, government policies, and cost and availability of compressed natural gas. A general multi-variant financial model was developed to aid in the analysis. The model may be used by companies who wish to determine if switching to natural gas would be feasible for their operation.

Population growth requires increases in supporting infrastructure and nowhere is this more important than in the provision of water supplies to support new residential development. The use of greywater (GW) systems in residential applications provides promise for more efficient use of existing water supply systems while new sources are brought online. In addition, GW system use provides benefits to water, sewer, and electrical infrastructure which culminate in reduced CO₂ emissions. A case study of these potential impacts was performed using environmental life cycle assessment and found significant reductions in CO₂ emissions and water consumption resulting from decreased electrical use for treating both potable and wastewater in two Northern Colorado cities.

The movement to construct high performance "green" buildings has had unprecedented market growth and continues to become a mainstream practice for constructing schools in the United States. This paper will consider how the results of government requirements for higher performance school buildings may affect the health and performance of students. The research focuses on educational leaders' perceptions of how they would prioritize green building strategies based on recent governmental policy that requires building green schools. There is clear and compelling evidence that schools currently built to specific green standards of indoor environmental quality, specifically lighting, result in healthier and more productive students. Interview results concluded that educational leaders' perceived energy savings strategies to be more important than indoor environmental quality in the design and construction of new schools.

The literature stresses the importance of the role building adaptation plays in detaining building deterioration and delivering building sustainability. Nevertheless, attributes that influence the determination of building adaptation potential remain unknown to the readers. Thus, this research intends to address this problem by identifying these attributes from occupants' perspective. Personal interview survey with questionnaire provided the basis for the study. The targeted respondents were occupants of public housing in Singapore. The findings show that these key attributes could be grouped into four categories: occupants' attitudes before adaptation, housing obsolescence before adaptation, expected impacts during adaptation, and expected impacts after adaptation. Identifying the key attributes would assist policy makers in obtaining an accurate result of building adaptation potential, which will enable them to select the right buildings for adaptation with the intent to optimize the allocation of limited resources like budget and to promote the sustainability of existing public building stock in Singapore.

The desire to create construction operations that have a minimal negative energy and environmental impacts are of great importance for the domestic and global construction community. Despite the fact that are several codes, specifications, and certifications that have been established to address energy and environmental sustainability with regards to site location, materials selection and architecture/engineering design issues, there has been minimal investigation regarding the sustainability of the construction operations which address their impacts on energy consumptions and environmental protections. This paper describes the author's efforts to understand the current legislation, codes, and certifications increasing the sustainability standards for construction operations. First, the researchers conducted a thorough literature review on the current codes, regulations, and certifications with focus on ensuring the design of a proposed facility meets sustainability measures as well as the codes and regulations in place that influence that project development approval process. Second, this paper summarizes the current best management practices used in the construction industry today with regards to energy and environmental sustainability.

This paper presents a novel finance project delivery concept, Savings to Sustainability (S2S), that bridges the existing gaps between energy projects implemented using alternative financing mechanisms, sustainability initiatives, and greenhouse gas reductions. Bridging these three areas will have a synergistic effect in terms of meeting Federal agency goals for energy, water, and greenhouse gas (GHG) reduction. Although reducing energy results in reduced GHG emissions, financial savings is the major driving force behind Energy Savings Performance Contracts (ESPC). The aggressive requirements pertaining to sustainability and GHG reduction goals requires an integrated and more holistic approach to retrofit and renovation projects. The S2S finance project delivery method enables existing buildings to achieve net zero carbon through a graded approach that includes energy & water efficiency, on-site renewable power generation, and green power procurement.

LEAP estimates the potential financial benefits associated with implementation of various sustainable design strategies outlined in the LEED Rating System. These financial benefits come from two primary sources: (1) reductions in operational costs resulting from energy and water efficiency measures, and (2) increases in employee productivity as a function of improved indoor environmental quality and occupant satisfaction. The estimates of productivity enhancement are based on research outlining productivity improvement as a function of different indoor environmental factors. LEAP is a universal tool that can be applied to any building certified under LEED v2.2 or LEED 2009. The purpose of LEAP is (1) to assist real estate brokers in marketing LEED Certified space, and (2) to assist perspective owners and tenants in making informed decisions based on potential economic benefits associated with occupying a particular LEED Certified space.

The incorporation of sustainability principles into project design and operation processes has been profoundly changing the construction industry. This change has caused an increasing number of projects to pursue a green certification, such as the Leadership in Energy & Environmental Design (LEED) and Green Globes certifications for building projects or the Green Leadership In Transportation Environmental Sustainability (GreenLITES) and Illinois-Livable and Sustainable Transportation (I-LAST) certifications for transportation and highways projects. While a great body of knowledge has been established at the construction project level, little is known regarding social and environmental responsibility at the construction corporation level. As many modern construction projects have started to favor green contractors and encourage green processes, such ignorance is cause for concern. Therefore, based on the extensive review of sustainable rating practices in other industries, such as financial services, retail industries, universities, and standardization organizations, this paper proposes a framework for a Sustainability Rating System for Construction Corporations (SRSCC) and 77 key sustainability indicators covering three dimensions of sustainability (social, environmental, and economic) and four elements of construction corporation (service/product, operation process, administration, stakeholder). With comparing this framework to existing sustainable rating systems in the construction industry, this paper delivers four insightful results, which could be used to improve the sustainable performance measurement both for the entitle construction industry and the individual corporation.

This paper examines the development of a broadly applicable comparative assessment framework for resolving design/specification dilemmas resulting from the clash of socio-environmental and marketplace ethics. First, the study frames the ethical standings and conflicts of each of these intentions. This process involves an initial examination of the diverse and conflicting conceptions of ‘green' or ‘sustainable' design. Next, a review of marketplace and consumer culture will follow, including the effects of globalization and the ‘green revolution'. The study then introduces the notions of ‘greenwash' and ‘greenspin,' along with their implications to architecture and construction. Findings in this investigation include the development of a rational and effective determinative assessment structure. The relevance of such a framework lies in its potential application to the specification of products and/or systems utilized in the construction of architectural, engineering, and design projects intended to address socio-environmental concerns. Such a ‘specifier-based' assessment tool will allow for subtle yet essential distinctions specific to many such projects, thus avoiding skewed prescriptions by well-intentioned ‘third-party' agents.

The Construction Management program at California State University, Fresno has been striving to integrate community projects with instruction to enrich students' learning experience and help improve the local community. The same "learning by doing" strategy is also applied to its education on sustainable design and construction. Campus is one of the closest communities to students in their daily life. Engaging students in decision-making regarding the "sustainability move" on campus not only allows the campus management to get valuable input from its end users but also has a profound impact on students learning and personal growth. This paper presents the learning and findings from several green material research projects developed through partnership between the Construction Management program and the campus facilities planning department.

Construction programs in the United States play a vital role in sustainable construction education by producing construction professionals having knowledge related to sustainable construction. The primary objective of this study was to examine baccalaureate curricula for sustainable construction offered by construction programs in the United States. A systematic search of the curricula of construction programs offered by the Associated Schools of Construction (ASC) member universities was conducted to identify courses on sustainability or its variants. Results show that one third of the member universities offer individual courses on sustainable construction and there is significant variation in course objective, level the courses are offered and prerequisite for the courses. A matrix comparing the course objectives of the sustainable construction courses presented in this paper clearly indicates the lack of general consensus on the content of the courses and the delivery method.

Construction safety is a critical component of social sustainability, since it considers the health and welfare of construction workers. Construction activities are generally physically demanding and performed in harsh environments. Anecdotal evidence suggests that physical strain may lead to accidents and injuries. Moreover, excessive physical strain can increase the risk of developing musculoskeletal or cardiovascular disorders. Thus, physical strain may deeply affect workforce's wellbeing in the short and long term. Therefore, a monitoring system that is able to assess workers' physical strain may be an important step to enhance social sustainability of construction. Recently-introduced Physiological Status Monitors (PSMs) have overcome the past limitations allowing physical strain to be monitored without hinders workers' activities. Three commercially-available PSMs have been selected and a testing protocol has been developed to assess PSMs' reliability in monitoring construction workforce during dynamic activities. The selected PSMs are presented along with initial results that confirm that recent advances in wireless telemetry and sensing technology can potentially affect construction sustainability.

Design and construction professionals who have studied sustainability know that sustainability encompasses social equity and economic equity as well as environmental equity. The vast majority of literature on social sustainability in the built environment focuses on regional urban planning issues, not on specific actions that capital projects owners and design professionals can take. Prevention through Design (also known as Design for Construction Safety) is an emerging trend in the design and construction industry in which design professionals consider the safety of construction workers during the design phase. The paper provides an overview of the PtD concept and suggests PtD should be a required aspect of social equity on capital projects. The barriers to diffusion of PtD—lack of knowledge, higher costs, industry structure and fear of liability—will likely challenge other social sustainability initiatives as well.

The existing architecture, engineering, and construction (AEC) industry has a fragmented nature where each team member works in isolation away from a whole-systems thinking. It is a challenge to produce sustainable buildings with systems optimization and multi-disciplinary collaboration among different disciplines. It is therefore crucial to help AEC students, learn how to exchange information and work in teams for effective design and construction of sustainable buildings. This paper presents a senior level course, taught at Michigan State University that utilizes a teamwork approach to teach sustainable built environment practices. The study tests the proposition that integrated student teams produce more comprehensive outputs for sustainable projects, by using mixed methods of data collection: observations, interviews and social network analysis. The results showed that teams with high degree of interaction, reliance, and trust came up with creative sustainable solutions and had better articulation for every aspect of the project, and its problems.

To achieve national goals to reduce the energy use and carbon emissions from buildings, there is a need to efficiently renovate the existing building stock to improve energy performance. In response to this need, this study includes a literature review of barriers to the delivery of renovation projects. The barriers and solutions offered in the literature are compared to barriers and solutions from a case study of a successful building renovation for improved energy performance. For example, one barrier to building renovations for improved energy performance is unforeseen conditions, which can cause project schedule delays and cost increases. A potential solution for this barrier, identified in the literature and in the case study, is the use of a comprehensive building inspection guide to evaluate existing building conditions and reduce the risk of unforeseen conditions. Widespread adoption of this and other solutions will help deliver affordable renovations for improved building energy performance, which is a necessary step for increased market penetration.

Due to rapid urbanization, building energy consumption has considerably increased over the past decades. The building sector's share of global energy use and greenhouse gas (CO₂) emissions is estimated to be as high as 30 percent and 40 percent, respectively. To improve the energy efficiency of building designs, the design parameters that may influence building energy use must be accurately defined and predicted. The aim of this study is to investigate the set of parameters that significantly concerned with building energy consumption. Utilizing the U.S. Commercial Buildings Energy Consumption Survey database, 22 design parameters were identified through the analysis of the literature. Then, a pre-processing, including missing value handling and outlier rejection, was performed on the collected data. Four well-known feature selection methods were examined to select more representative parameters. Then the baseline model was applied to investigate the set of parameters influencing building energy consumption. The results of this study demonstrated that the set of parameters selected by stepwise regression has the strongest influence on building energy consumption.

The objective of this study is to quantify the effects of radiant barrier system on heating and cooling loads in residential buildings. To achieve this objective, two identical buildings located in LA, one with a radiant barrier system and one without a radiant barrier system, were instrumented with thermocouples and heat flux transducers. Data were collected for eight months to determine the amount of energy savings gained by installing the radiant barrier in the attic. A 3D transient Finite Element (FE) model was developed to predict the attic temperature profile. This model was validated based on experimental measurements. Results showed that radiant barrier reduced the integrated heat flows from the attic to the house by approximately 18% and reduced heating loads by 6%. A parametric study was conducted to formulate a simple regression model that can be used to predict the temperature of the attic insulation.

Building energy conservation has attracted much attention in recent years. It is also known that operating and embodied energy for buildings accounts for a great part of life cycle energy use. To achieve sustainable development, the building life cycle energy use is evaluated based on the exergy method. The relationship among exergy, energy and sustainable development is presented. In this paper, a method, which balances the building materials embodied energy and operating energy based on the exergy analysis method, is introduced. Finally, the problems are also discussed.

An airside economizer is an energy-efficiency measure for buildings; this air damper and automatic control scheme is considered one of the most popular energy-saving measures for mid-sized and large buildings' all-air or air-water air-conditioning systems. Airside economizers have been widely used as part of many air-conditioning systems for commercial, institutional, industrial, and large residential buildings in the United States and elsewhere, and researchers continue to study the airside economizer's control algorithms, setpoints, and performance in different climates and for various building occupancies. But in mainland China (PRC), HVAC engineers have not typically considered use of airside economizers, due to unfamiliarity or poor initial experiences with them. Also, because of failure of components or poor maintenance airside economizers can be energy wasters instead of savers thus further hurting their reputation in China. Although many cities in China are located respectively at similar longitudes and latitudes as cities of the U.S., the weather in China is different and often more humid than in much of the heavily populated regions of the U.S. Outdoor air pollution is also severe in more major industrialized cities of China than in the U.S.. This paper analyses the usage prospect of airside economizer from a climate distribution perspective, and the air-quality situation and the typical "conventional" air-conditioning systems used in China.

One of the goals of US Green Building Council (USGBC) is to minimize the energy consumption of buildings. Several initiatives and steps have been taken by the USGBC and the construction industry to promote sustainable and energy efficient buildings. Institutional buildings, such as schools, colleges, universities, should be made energy efficient so that further depletion of fuel energy sources in the world can be reduced. "Green" buildings are designed to save energy costs by reducing the energy consumption. The objective of this study is to determine the difference in energy consumption between Green School Buildings (GSB) and Non-Green School Buildings (NGSB). This study collected data regarding energy consumption for 30 Green School Buildings and 30 Non-Green School Buildings constructed by Clark County School District in Nevada. A statistical analysis was performed to determine whether there was a significant difference between the energy consumption of a GSB and a NGSB. The results showed that GSBs consumed significantly less energy than NGSBs. About 32% less energy was consumed by GSBs compared to NGSBs.

Unstructured & improper planning of urban morphologies (geometry & placement) is common in urbanization & the buildings' roughness & geometry within have caused a host of ventilation-related problems. This study postulates that there is an association between certain morphological variables & urban wind flow & one of the morphological variables Gross Building Coverage Ratio (GBCR) has been singled out for a preliminary parametric numerical study here. From the results of the study, interesting trends can be garnered & this supports the high possibility of development of an overall ventilation potential model using the various morphological variables (in form of indices) as independent variables for input. This will be useful for development of climate-responsive design & planning regulations specific to high-density residential estates in tropical Singapore.

Shading has been always recommended as a way for solar control and reduction of heat gain in buildings. It blocks direct solar radiation of the hot desert environments, where cooling loads are significant. A number of publications addressed the effect of shading wall openings, such as windows, on energy consumption. However, a limited number of publications addressed the effectiveness of the shading of the solid parts of walls under extreme desert conditions. This paper investigates the energy saving potential of the shading of external solid walls of buildings. Simulations were conducted using the EnergyPlus Software. Annual energy consumption was calculated for two types of wall configurations and different wall shading alternatives. Values were derived for different cities having different climatic conditions. Conclusions were drawn on the best utilization of external wall shading methods.

Energy efficient and zero or zero net energy buildings are quickly gaining more importance and popularity among contemporary building practices. Typically several renewable energy harvesting systems are combined together to reach the objective of zero (net) energy consumption which results in a unique challenge properly sizing each energy system. Because a standard design procedure does not exist, inappropriately sized energy systems are often installed. In this paper, a holistic design procedure is introduced which determines and optimizes the corresponding size of renewable energy systems in a typical residential house to meet the total energy demand. To evaluate this procedure a case study was implemented for a zero net energy test home (ZNETH) at the University of Nebraska with three energy sources including a geothermal system, a photovoltaic panel (PV) system and wind turbine systems.

This paper aims at developing solar screens for use in front of windows under the clear desert skies. These external perforated panels revitalize a traditional solution named "Mashrabeya". They contribute to sustainability through utilization of natural light. In this paper, series of experiments were conducted using Radiance software. The impact of solar screen axial rotation on indoor daylighting of a residential setting was investigated. The effectiveness of the axial rotation was demonstrated. Screen influence on daylighting was strongly dependent on the orientation of the window and time. Illuminance adequacy was tested. The North and South orientations with upward and downward horizontal axial rotation were most affected when the rotation angle increased from 0° to 30°, especially in the summer season. In the East, the winter season was the most affected by the rotation. As a response to changing the rotation angle, a linear increase relationship was observed in all orientations.

This paper develops a Building Life Cycle Cost (BLCC) analysis of a sustainable house, Zero Net Energy Test House (ZNETH) in Omaha Nebraska to evaluate its economical benefits over its useful life. With the aid of the ZNETH's Building Information Model (BIM), different design alternatives could be easily obtained and economically assessed through model-based cost estimation to determine the lowest life cycle cost possible with an earlier payback return. This decision making study also utilized theoretical energy data to value the ZNETH's sustainable features. It was found that the ZNETH current design of a geothermal system, two solar panels and a wind turbine did not show greater economic benefits than costs within a 20-year life time. The ZNETH also features other sustainable elements such as Insulated Concrete Foundation (ICF), an Exterior Insulation Finishing System (EIFS), and a closed loop geothermal system.

This paper aims to determine the performances of the solar chimney system under a hot and wet tropical weather using an actual full scale solar chimney installed in an operating building. Results showed that under cloudy conditions, the low solar irradiance can induce an average air speed of 1.5 m/s and 0.4 m/s within the solar chimney ducts and classroom respectively. The second objective examines the influences of the position of the solar chimney inlet on the air speed and movement within the classroom. Experimental data and smoke test results showed that lowering the inlet to occupancy's height significantly increased the air speed to a maximum of 0.6 m/s within the classroom. Further research is required to determine the combine effects of the position of the solar chimney inlet and fenestrations on the classroom.

Currently, there are many developers interested in procuring and designing energy efficient, sustainable and near zero carbon buildings including the National Health Service (NHS) in the United Kingdom. The author of this paper is currently employed as a researcher and advisor, assisting with the development of a design brief for the new Alder Hey Children's Hospital Development in Liverpool, UK. In undertaking this research, the author has become aware of the difficult decision that the client faces in selecting the best value for money/sustainable tender bid. This author believes this decision is made more difficult because sustainability issues have completely changed the process for selecting successful bidders. In fact, the author believes there is a "knowledge gap" in this area. This paper outlines the project being undertaken for the NHS and details of the development of the decision making aid for selection of renewable/sustainable energy systems for buildings to date.

A study has been carried on to determine the effect of building openings and orientation vis-à-vis the needed energy to keep interior spaces within the comfort zone. For this analysis the average temperatures throughout the year and average diurnal temperature swings at four different locations were applied, indicating the effect of exposure to morning direct radiation, versus noon and afternoon and the potential energy gain from optimized orientation of buildings. Data such as temperature values were assigned the anticipated average based on collected data. Depending on latitude and local climate, it was evidenced that minor angle shifts may produce noticeable results in terms of energy gain or block. It is also evidenced information on the time energy is gained is as important as information on the daily overall gain. The energy gain of applying optimized orientation produces no environmental impact and negligible if any initial financial costs.

Sun-breakers are commonly used as external shading devices in buildings. They are composed of protruding surfaces around window edges to block solar rays from entering into the spaces to reduce energy cooling loads Good design of sun-breakers blocks solar rays during hot summer months to reduce cooling load, while passes them during cold winter season to decrease heating load. However, this design method may be over-simplified for global use. There are many locations where winter solar access generates cooling loads. Also, months that are similar in solar path location -e.g. August and April- cannot be similarly treated, as their climatic thermal conditions are different. Current design methods may use geometrical analytic Approaches to design sun Breakers, others are based on energy saving, usually are search methods. This paper reports on a research that aims at enhancing current methods for defining the optimum shape geometry of sun breakers. By providing energy based cut-off date that can be used with geometrical methods for design of shading devices for each geographical location. Cut-off date is defined according to optimum annual energy performance, including heating and cooling, and lighting loads. The energy performance of a typical building space was modeled using Energy Plus software. Sun breaker edge profiles were defined to fit around this window by geometric modeling of the solar rays for monthly time periods. Annual energy performance of series of edge shapes was simulated. The optimum edge profiles and cut off months and hours were defined for different locations. Results demonstrate that the cut-off date depends on both Latitude and climatic Conditions, using the method can lead to the design of sun breakers with significant energy savings.

One of the major barriers to advancing the competitiveness of sustainable construction in the U.S. market is that "traditional" construction firms do not have accurate data on labor productivity for sustainable construction projects. This negatively impacts their ability to reliably estimate a construction project's schedule and cost. Due to the nationwide diverseness and complexity of the construction industry, labor productivity comparison is difficult. Even for conventional projects minimal research has been performed on nationwide labor productivity measurement, with most research being jobsite specific. This paper uses productivity data that has been collected on jobsites in Kansas. Using the data, various statistical analysis methods were applied to determine the productivity rate differences between two projects and compare it to data from RS Means, which is an industry standard. Statistical analysis results prove the possibility of using labor productivity to control the labor cost of a "green" project. Furthermore, the results can be used by construction firms entering any regional market as a basis for a comparative reference. Through this advancement a firm may enhance their ability to perform competitively in the sustainable construction market.

This paper reviews the sustainability initiative enacted by a Phoenix General Contractor and how the initiative transformed the procedure used for document distribution on a 750,000 SF healthcare facility. The research identified how a simple workflow modification substantially improved the documentation management for the construction team, impact project quality and efficiency. The methodology used through a Building Information Modeling file sharing website enhanced document distribution and control, reducing costs and staffing typically associated with document control.

The nature of construction jobs often exposes construction workers to hot weather conditions. Incidence of extreme weather events is rising with climate-related changes observed globally and in the United States. Heat illness prevention strategies have unknown impacts on craft time utilization in the construction industry. A new approach, which relies on the integration of worker physiology models, sampling methods, thermal comfort theories, and meteorological knowledge, is employed in this research to develop a framework for assessing climate-related heat effects on craft time utilization. The findings of this research will provide great implications for increasing the productivity and sustainability of U.S. construction workforce.

Over the past ten years the LEED rating system has been continuously focused on the various research domains in order to address the sustainability issues in built environments in the United States and other countries. LEED credit weighting provides a logical and rational approach to producing numerical scores in each category. Though it was developed in an extensive collaborative process, there has been controversy over the credit weightings system. The allocation of credit weightings still leaves much room for consideration due to the arbitrary decisions based on the developers' judgment. Thus, this paper attempts to address the sensitivity and reliability of the optional credit weights among six categories. We conducted two experimental designs using point-by-point data for 43 LEED projects certified under LEED-NC version 2.0 series. The findings from this study will provide the LEED project teams with insight into credit implementation in the predesign stage of potential LEED projects.

Although building less space contributes to sustainable design and construction, having less space without a clear rationale can impair user experience (UX) after a facility is built. However, our triangulated case studies show that the current assessment of UX is qualitative and intuition-based, which is not adequate in predicting the UX for decision-making about a space program (SP). We argue that an activity-based assessment tool can help planners better predict the impact of an SP on the UX in a quantitative, model-based, and detailed manner. We propose three research tasks required to develop the tool: (1) formalizing the relationship between the user activities and the UX, (2) measuring the predictors which impact the UX given the information basis planners have, and (3) validating the tool by a structured experiment. This research can contribute to sustainable design and construction by providing a clear rationale for making decisions about an SP during the programming phase.

The significant amount of waste generated from construction demolition has become a chronic problem in Lebanon. In the city of Beirut alone, approximately one million ton of construction demolition waste (CDW) has been generated over the past two years. The country is suffering from a constant problem in the management of its solid waste; and therefore, devising methods to manage the amount of CDW is a must and is the primary goal of an ongoing research at the American University of Beirut. This paper presents the first major step in this research effort. The paper studies the quantification, composition, and managing of CDW in Lebanon by examining three case studies consisting of 50 to 60-year old buildings being demolished for reconstruction. Based on the case study analysis and a set of interviews conducted with demolition contractors, the paper proposes a set of rules and regulations necessary for proper handling of CDW in the context of the Lebanese construction industry.

With rapid development of green building in China, the government and construction firms are increasingly focusing on construction waste recycling which is a branch of green building. However, with simple disposal methods, low efficiency and serious environmental pollutions, China lags behind with other developed countries in the technology of construction waste recycling, which urgently needs improvement. This paper will take Chongqing as an example, which is one of the five centre cities in China, to illustrate the present situation and the existed problems in this field in China and then puts forward some corresponding countermeasures from the aspects of technology, management and policy, aiming at enhancing the level of construction waste treatment in China.

The Leadership in Energy and Environmental Design (LEED) rating system has gained increasing attention during the past decade. Many papers and books describe the owner, designer, and general contractor's roles in LEED building projects, but almost no research has been conducted to investigate the role of subcontractors in this process. This paper describes a study aimed at exploring subcontractor involvement in LEED building projects so as to fill in the knowledge gap and to provide information for future research studies. In this research, interviews with several leading general contractors in the Pacific Northwest are conducted to find out the general contractor's perspective about this issue, and a case study, the Oregon State University Linus Pauling Science Center, is used to illustrate subcontractor involvement in gaining every LEED credit. The results show that subcontractor involvement depends on the trade and the contracting method used for the project. It is also suggested that the knowledge of subcontractors regarding LEED does not limit their ability to perform LEED projects, and education for subcontractors will be helpful but not necessary in terms of LEED.

One of the ongoing challenges in the quest to make the built environment more sustainable is to identify and mitigate environmental impacts in all phases of buildings, from design to construction to use and maintenance and finally end of life phases. In this study we compare the life cycle environmental burdens of constructing Composite Metal Deck and Hollow Core floor systems for commercial buildings by using a Hybrid Life Cycle Assessment (LCA) approach. The study covers material extraction (cradle-to-gate) and construction (gate-to-gate) phases and includes a detailed assessment of both direct and supply chain impacts. A comprehensive set of results is obtained from the study. These results are presented in several categories for comparative assessment - energy use, Carbon Dioxide (CO2), Carbon Monoxide (CO), Nitrogen Dioxide (NO2), Sulphur Dioxide (SO2), _PM10 and VOC emissions. Other categories include solid waste and liquid emissions.

Green buildings are expected to integrate renewable energy technologies to buildings. Therefore, builders (construction firms) are expected to handle innovative technologies' integration during the construction project process. Meeting the stakeholders' expectations in an effective manner within the integrated project delivery environment is challenging. The required process expertise is beyond the traditional MEP process expertise. These technologies comprise clean energy technologies such as solar, wind, hydrogen (fuel cells, biomass), bio-energy, geothermal and waste treatment to energy technologies for wide range of wastes such as municipal, industrial, bio-hazard and many other types. The paper explores the expected qualifications - in regards to innovative green technologies' integration process to buildings - from construction firms during pre-construction, construction and post-construction phases. The new qualifications such as developing skills in life cycle cost analysis, taking initiative in BIM applications, managing knowledge driven commissioning process and acquiring knowledge in post-occupancy evaluation define the new roles for construction firms in innovative green technology integration process in building construction.

Waste in the construction industry has been the subject of several research projects around the world in recent years. Researchers implement different methods to reduce the amount of waste in construction industry. One of effective methods is application of lean approach to construction industry. Lean construction is a result of the introduction of a new form of production management. Although lean construction is still evolving, the generic principles, techniques and tools of lean construction can already be applied. Waste reduction in order to improve performance is one of the basic concepts of lean thinking. In general, project managers tend to conceptualize "waste" as physical construction waste, but there are noticeable wastes in the construction processes which are named "non value-adding activities" by lean construction theory. In this paper, the waste quantity of construction processes in any format has determined through discrete event simulation based on lean thinking approach. Furthermore, a case study conducted to reveal the result of lean thinking application in a real manner. Results show that the construction processes have the high potential of optimization via implementing lean construction principles and computer simulation.

To explore the current situation of China's management of construction waste, person-interviews were conducted in Beijing, Shanghai, Chongqing, and Shenzhen of China. The result of the interview revealed four main problems: first, government lack of management; second, insufficient attention to the construction process; third, poor technical conditions; fourth, poor transportation management system. Based on these findings, this paper tries to propose a model to enhance the performance of the China's construction waste management. The model includes: implement the functions of government, promote technology innovation, increase the employees' awareness of environmental protection, minimization site waste, standardize construction waste management and establish incentive mechanism.

Sustainable construction practices that take into account the ecological, social, and financial performance of buildings are gaining acceptance in many areas of the construction industry. As the baby boomers begin to retire, the provision of healthy living environments for the elderly in the community is a growing concern, especially for those suffering from dementia. Because most individuals with dementia are cared for at home until their condition requires medical supervision, healthy living is often a challenge affecting the whole family. This study examines how best to implement sustainable strategies that support healthy and safe living environments for individuals with dementia and their families. After considering how the characteristics and symptoms of dementia can be ameliorated by careful environmental design, relevant familial and community characteristics that support healthy living for the target population are described and ways of incorporating sustainable strategies to provide a healthy living environment explored. Using an evidence-based approach, the interdisciplinary research team conducted an extensive review of both medical and construction journals to develop a set of practical guidelines designed to assist those grappling with these difficult issues.

Sustainable practices are beginning to be adopted in the hotel industry, saving energy, water, and resources and thus helping to preserve the environment. However, there is inevitably some conflict between sustainable practices and hotel guests' satisfaction and comfort as the conservation of resources could detract from the quality of a guest's experience. Here we present a case study of two LEED platinum hotels, identifying and analyzing sustainable practices that balance the twin goals of sustainability and luxurious environment while at the same time enhancing the hotels' financial strength.

The A/E/C industry needs effective tools to support visualization of sustainable scope development. Simple assessment systems, such as variations of the LEED checklist, are commonly used to establish a project's sustainable goals as well as to monitor progress towards these achieving these goals. Despite their ease of use, these do not always identify issues in sustainable scope development, such as specification or procurement of unacceptable materials for a project's sustainability goals. They also mask the full range of environmental impact metrics, such as carbon emissions and water intake, that might help compare alternatives. To illustrate the importance of effective management of the sustainable scope development process, the authors analyzed the attained credits of several LEED certified projects and identified success factors in multiple case studies of LEED-certified projects. These factors help identify of components of a framework to improve the effectiveness of sustainable scope development.

Bridge Management Systems (BMS) play a crucial role in maintenance and rehabilitation decisions related to bridges. This paper presents using Bridge Information Modeling (BrIM) framework that adopts BMS features including; databases, inspection module, and condition assessment module. The proposed BrIM framework creates a database of bridges' components and generates inspection spreadsheets. It also visualizes bridge components considering the information stored in the database and inspection spreadsheets, using Structured Query Language (SQL) statements. The paper presents the integration of BrIM with advanced analysis technique to calculate the structural condition of bridges. This integration is achieved using C# programming language.

Based on the dogma of Modern Architecture, most contemporary architects consider slender details and clear separation of architectural parts intrinsic to good architectural design thinking. Energy efficient design on the contrary which has to rely on heat retention, prevention of thermal bridging and airtight construction to reduce unwanted heat transfer through the envelope needs layers. A new aesthetic has to be found for a building envelope with increased need for insulation, seals and gaskets and ideally without penetrating elements which could conduct heat from hot to cold. Considering current construction techniques, conceptual design thinking, aesthetic values and building science this paper will analyze energy efficient envelope detailing of the US Department of Energy's (DOE) 2009 Solar Decathlon homes. The paper will evaluate the influence of energy efficient envelope detailing on aesthetic appearance and how technical requirements could be integrated into a conceptual aesthetic to promise greater acceptance amongst architects.

In the area of infrared building inspection, 2D thermal imaging cameras are the latest and most promising technological innovation with the capability to detect commercial as well as residential buildings heat variations. However, 2D thermal images have the limited perception in visualizing the buildings. As an on-going research, this paper aims at creating 3D energy performance model using 3D Light Detection and Ranging (LIDAR) system integrated with a thermal imaging camera. Methodologies of avoiding image distortion, data acquisition, and data fusion are also presented in this paper. 3D energy performance model will be an influential tool for representing and visualizing building conditions that is utilized by architects, builders, and contractors. The created model consists of point clouds, in which each point contains coordinates, temperature, and other information. A preliminary field experiment on a building is introduced in this paper and has shown promising results.

A need exists in the Deep Energy Retrofit industry to educate and enable homeowners to make informed decisions about energy efficiency projects. This paper describes a novel approach to inform the non-building scientist about the physics of building performance in order to motivate them to invest in energy efficiency measures for their homes. The aim is to use animated multi- and hypermedia tools uploaded to the social media to reduce the amount of time and instruction needed for homeowners to understand the value of energy retrofits.

A renewed cultural attitude towards recycling has given designers the agency to once again consider alternative products as a growing part of mainstream construction materials. However, the 21st century use of these materials must be predicated on the idea that they be employed in elegant and efficient construction processes. We ask: How can the building and construction industry more readily employ non-toxic, industrial by-products in the creation of efficient and expressive building form? Our solution proposes that form not be tied to a preconceived surface or form-making process, but that form be responsive to material components as the primary and delimiting factor in its articulation. By designing the geometry of a form through its material constraints, we can minimize the amount of customized components while maximizing form-making possibilities and ease of construction. This paper will outline our research demonstrating how architects might expand these systemic processes to larger objects and systems using a combination of relatively simple geometric definitions along with parametric modeling software to map fixed-sized objects across complex surfaces. The primary scope of the investigation involves the geometric analysis and modeling of recycled industrial waste and the prototyping of assembly methods using digitally manufactured supports and connections. By recycling industrial by-products, which pose no health hazards, we demonstrate that sustainable design practices can effectively mitigate waste while contributing to alternative energy discussions in our local community.

The availability and advancement of material technology and the acceptance has led to the production of higher grades of concrete. High strength concrete (HSC) offers superior engineering properties i.e. compressive strength, tensile strength, durability, modulus of elasticity and overall better performance when compared to the conventional concrete. Due to its enhanced strength and improved structural properties, high strength concrete has been increasingly used for the past two decades. In this research, many published studies on the behavior of HSC beams have been discussed and analyzed. High strength concrete used in this study is defined as concrete with compressive strength exceeding 50MPa. Although there are many publications proposing stress block models for HSC beams, a universally accepted stress block model is yet to be developed. In most design standards, the conventional rectangular stress block developed for normal strength concrete (NSC) is still being used for design of HSC beams. In this paper, published work has been analyzed to establish some understanding of flexural behavior of HSC beams. Models proposed in various design codes and standards have been analyzed to compare the experimental and theoretical moment capacities. A number of spreadsheets in Excel were developed using available data and various graphs were plotted to determine the accuracy of the code provisions for calculating the ultimate moment capacity of beams. Based on this, conclusions are drawn for the design of high strength concrete beams in flexure utilizing different code provisions.

Since 1880s, the lighting society has been working on optimizing lighting energy consumption in low-carbon buildings without sacrificing visual performance. There are two difficulties that hinder this goal. First, lighting profession has not yet well agreed on a simple visual task that could be widely adopted in practice for determining threshold light levels without losing lighting quality. Second, there is a lack of quick, accurate, and reliable techniques for light and geometry measurement in an entire scene. This paper introduces two solutions to these problems, including an equation for predicting legible text viewed at different angles, and innovative high dynamic range (HDR) photogrammetric techniques. This study then tested a windowless classroom for optimizing lighting energy saving without sacrificing legibility. Outcomes would be recommended for creating and maintaining low energy buildings with enhanced legibility.

In Kansas, due to processing of soft limestone in the quarries, a large amount of fines are produced. The problem has been exacerbated by the introduction of Superpave system for hot-mix asphalt (HMA) that tends to use coarser aggregates and materials with lower fine content. This has resulted in a large amount of quarry waste being available as a construction material. Again due to binder issues, the uses of reclaimed asphalt pavement (RAP) in Superpave HMA are limited. Geocellular confinement systems (geocells) are 3-dimensional honeycomb-like structures filled with an in-fill of some available materials that vastly improve shear strength of in-fill materials. The objective of this study was to test geocell-reinforced bases with RAP and quarry waste under a thin HMA layer under full-scale traffic loading. HMA pavement test sections with geocell-reinforced bases, with RAP and quarry waste as infill materials, were constructed at the Civil Infrastructure System Laboratory (CISL) of Kansas State University. The sections were paved with a 50-mm Superpave hot-mix asphalt HMA layer and instrumented to measure the stresses on top of the subgrade. The sections were loaded to 50,000 to 70,000 repetitions of an 80-kN single axle load. The calculated and measured responses show that on both test sections, stresses on top of the subgrade exceeded the unconfined compressive strength of the soil. It was concluded that the geocell depth and/or the thickness of the HMA layer need to be increased even for paved low-volume roads.

Over the last years, environmental and economic concerns have negatively affected societal development strategies. The construction and building community, including architects, designers, and builders, have been dealing increasingly with the issues of green building design and sustainability. This paper studies how brick construction can contribute to the national and global over-arching goals of high performance and sustainable development. Meanwhile, it was not the authors' intent to compare brick to or promote it over any other construction material; the following research objectives were attained: (1) analyze the sustainable properties of brick; (2) highlight examples of laboratory testing that substantiate sustainability features of brick; and finally (3) outline how masonry ordinances can promote sustainable development. Brick masonry provides various properties that support and strengthen the national and international strive for high-performance development; through emphasizing added quality, appearance, durability, maintenance and environmental friendliness, and character to the built environment. Bricks are known for high strength, durability, and long life span. By nature, masonry is not prone to insects' attacks and is more resistant to fire progression. Upon demolition after design life, bricks can be easily recycled and reused into other materials and practices. Manufacturing of bricks may involve usage of waste materials. The use of compressed earth blocks provides the feeling of natural environment within the building. Although bricks have relatively lower R value for thermal insulation, the use of proper insulation system and the thickness of the brick can make up for good insulation. It is perceived that incorporating masonry ordinances in the building regulations of various U.S. cities demonstrates a growing administrative understanding of the sustainable benefits of brick. The authors hope that their study provide a comprehensive, yet summarized, reference that would help increase societal awareness towards the importance of brick masonry towards green building construction for future generations. Further investigation is needed to provide a system that facilitates the brick masonry construction and make it less labor intensive.

The objectives and scopes of this research were confined into the formalization of strategies and technical procedures for recycling PEMs back to permeable wearing courses. The most relevant boundary conditions were the following: mitigating the drawback of clogging and its related consequences (decay of acoustic and drainagebility performance over the time), preserving traditional (bearing properties, skid resistance) and premium (silentness, drainagebility) performance; recycling high percentages of cold milled RAP-from-PEM, investigating on collateral effects in terms of sustainability. An experimental plan was designed and carried out, by specifying materials selection, production, tests on recycled PEMs, basic and advanced tests on surface and hydraulic properties of recycled PEMs, analyses and reports. Functional performance resulted quite promising and the tests carried out are encouraging about the possibility of achieving a satisfactory level of surface performance. Practical applications for rehabilitation interventions are outlined.

Tire derived aggregates (TDA) offer potential environmental, technical, and economical benefits for retaining wall applications. For example, when compared to natural soils, TDA materials offer the advantage of reduced lateral pressures and settlement due to smaller unit weight, and potentially higher drainage capacity. This paper presents a technical and economical assessment of TDA materials for retaining wall backfills. The technical assessment includes results on model retaining wall tests and also from centrifuge tests to assess the lateral pressures generated by TDA materials. The lateral pressures are compared to tests using conventional mineral soil backfills. The test results show TDA backfills generate lower lateral pressures for at-rest conditions and for active conditions. The lower lateral pressures, coupled with lower unit weights translate into substantially lower retaining wall costs due to savings from smaller wall and footing dimensions, and less steel reinforcement quantities associated with the lower loading demand.

Fly ash is one of the major industrial solid wastes. Many power plants of coastal cities in China produce a large amount of wet fly ash in sea water. Fly ash not only takes up significant land resources, but also causes pollution in soil and water. Sustainable utilization of wet fly ash produced in sea water is possible in civil engineering. For example, it can be used as backfill for embankments, retaining walls, and reclaimed land. Cement can be used to increase the strength and stiffness of fly ash if needed. To achieve this goal, a study was conducted to evaluate basic mechanical properties of wet fly ash by sea water. The primary test method adopted in this study was an unconfined compression test. Wet fly ash by sea water or fresh water was stabilized by cement. The test results show that the stabilized wet fly ash by cement had high unconfined compressive strengths, which increased with the cement content and curing time. The stabilized fly ash by sea water had a higher initial strength but lower long-term strength than that by fresh water.

In promoting sustainable construction in Singapore, regulations were introduced in 2009 that mandates for construction projects to meet GreenMark requirements. However, GreenMark does not have an impact in the selection of building materials. When it comes to evaluating the environmental burdens of building materials, Life Cycle Assessment (LCA) is a scientifically reliable method that can be used. Thus a survey was conducted to find out if LCA methods are being used in Singapore and to seek opinion regarding a possible integration of LCA into the BCA GreenMark Scheme. It was found that an overwhelming proportion of the respondents were not even aware on the conceivable use of LCA in making building material choices, but showed positive environmental attitude and generally support the integration of LCA methods into GreenMark. To conclude a LCA database on local building materials should be established and merged into currently available tools in the local industry.

This article reported a fundamental study in sustainable construction materials engineered by using natural fiber reinforced composites. Industrial hemp fiber composites were synthesized with recycled thermoplastic polymers by using extrusion and compression molding techniques. The effects of fiber/matrix volume fraction on composite's tensile, flexural strength and modulus were investigated. Surface morphology of natural fiber before and after treatment were examined by using scanning electron microscopy. This study indicated that hemp fiber composites with recycled High Density Polyethylene have desirable mechanical properties with regards to tensile strength, elastic modulus; flexural strength, and modulus of rupture at 40% of fiber volume fraction. It is interesting to observe that the tensile strength of hemp fiber with recycled HDPE composite reached to 60.2MPa at the 40% of fiber volume fraction, which outperforms hemp composites with virgin thermoplastic matrix reported in previous studies.

Buildings have a significant impact on the environment due to emissions of utilized resources. Building materials are the main component that should be taken into consideration when constructing new buildings. Attention should be paid when taking the decision of which material should be used. This decision bears significant environmental, economic, financial, and social influences. Selecting inappropriate materials can be expensive, but more importantly, it may preclude the achievement of the desired environmental goals. This research presents a framework that consists of two modules for selecting appropriate building materials in order to help decision-makers with the appropriate selection of conventional or green building materials. The modules of the framework are; system dynamics (SD) module and ant colony optimization (ACO) module. The paper describes the developments made in these two modules. The proposed framework helps to pursue sustainable environmentally friendly practices when selecting of building materials based on LEED credits and costs. A case study is presented to demonstrate the use of the proposed framework.

According to the Federal Highway Administration's (FHWA) National Bridge Inventory, one third of nearly 600,000 U.S. highway bridges are classified as structurally deficient or functionally obsolete. Since the majority of bridges were built using wood, steel or concrete, the same conventional materials have been used for bridge replacement or rehabilitation, imposing similar patterns for future deterioration. However, to address recent emphasis on durability, accelerated construction and sustainability, including "Going Green," new advanced materials are coming on the market. Developed in conjunction with scientists at Rutgers University, a manufacturing company named Axion International, Inc. was able to produce a thermoplastic composite, also called Recycled Structural Plastic Composite (RSPC), made of nearly 100% recycled post consumer and industrial plastics that would otherwise be discarded into landfills. This environmentally friendly thermoplastic was first utilized for railroad crossties and recently extended its application to bridge and structural members. In early 2009, the world's first vehicular bridges made of recycled plastics were built at Fort Bragg, North Carolina. Virtually all bridge components were made from recycled plastics. The bridges were designed for HS25 and the 71-ton M1 Abrams tank. Impressed by these developments, Fort Eustis in Virginia also decided to utilize this material to replace two aged railroad timber bridges. The world's first thermoplastic railroad bridges were designed to carry a Cooper E60 and a 260 kips alternate load. They opened in June 2010. A detailed design process and discussion on this cost-effective and environmentally superior solution will be presented in this paper.

The open platform screen door systems including the platform full height door system and the platform half-high security door system are studied in the paper. The three-dimensional mathematical and physical models are established respectively. The entrance/exit boundary of the model is the subway piston wind calculated from the one-dimensional flow equation. Under the platform full height door system and half-high security door system, the influence of air quantity and amount of heat of subway platform and station hall is analysis in different running condition of subway train for the influence of metro train piston wind. The result can offer a reference for the design and engineering application of subway train environmental control system.

This paper describes ongoing research and its application of Life Cycle Assessment (LCA) techniques to the problem of public school facility deterioration and resulting impacts on environmental health. Specifically, this project targets asbestos-containing materials (ACM) and lead-based paint (LBP). These building components were chosen due to the severity of their associated health risks and their ubiquity in the national school environments. Underway is the development of an LCA framework to describe and predict environmental impacts of facility condition, deterioration, maintenance and disposal alternatives. The present paper discusses the "goal" and "scope definition" phases of the LCA process.

With the increase of awareness on global warming, the interest in creating more sustainable communities is rapidly growing. Sustainable communities promote a lifestyle that is environmentally, socially, and economically sustainable. In an effort to promote sustainable communities and provide standard guidelines, the U.S. Green Building Council developed the LEED for Neighborhood Development (LEED-ND) rating system in 2009 as a tool to evaluate the sustainability of neighborhoods that get newly developed. While this is an important step in promoting sustainable communities, there is no rating system for existing communities. This research investigates the applicability of LEED-ND for assessing the sustainability of existing communities. Two communities in the city of Calgary, Canada, are evaluated using LEED-ND as case studies. The results suggest that LEED-ND provides a suitable evaluation basis, however, modifications are needed to make it fully applicable to existing communities. The paper provides suggestions as to how such modifications can be made.

As a global community, we face significant challenges related to reducing our environmental impact, taking a hard look at our development practices and identifying opportunities to reduce pollution, while revitalizing our communities to create safe, attractive and vibrant "people places". Moving forward we must critically consider how we plan, develop and construct not only our buildings, but also our neighborhoods and cities. Sustainability at the building level the first step, but it is merely one piece of the puzzle. Sustainability must start in planning at the community level, requiring a major paradigm shift, and an extension of our commitment to sustainable planning and design. This paper will provide an in-depth look at the model of "cellular" development, incorporating the principles of New Urbanism and sustainable design to create self-sustaining communities. This paper will also identify opportunities related to transit, parking and development to create more walkable, convenient and self-sustaining communities.

The Civil City paradigm calls for a broader understanding of the multidisciplinary nature of sustainability decisions relative to the interrelationships between the throughputs of the natural and built environments. These sustainability decisions involve competing and complex interrelationships at the local, regional, and national policy levels. These sustainability decisions often include tradeoffs among conflicting natural resource management policies, land-use planning decisions, industrial ecology activities, and urban infrastructure expansions. To increase this understanding the Civil City paradigm advocates for a systems-based philosophy that: (1) facilitates multidisciplinary public, private, and academic partnerships to fully-integrate the design, engineering, construction, operations, maintenance, and disposal of the natural and built environments relative to collaborative local and regional sustainability objectives; (2) develops comprehensive economic, social, and environmental policies to efficiently and cost-effectively allocate limited financial and natural resources at the local and regional levels; (3) provides innovative decision-making approaches to objectively assess and evaluate competing and conflicting multi-objectives pertaining to the sustainable utilization of limited local and regional natural resources relative to different economic, social, and environmental policy options; and (4) implements and monitors cost-effective managerial strategies to ensure the sustainable utilization of limited local and regional natural resources among the goods and services of constructed urban systems. This paper calls to action the people from the various professional disciplines to voluntarily come forth in collective response to participate in making our cities and regions more people-friendly, livable, sensible, and sustainable.

The City of Fresno in Central California has been struggling with severe poverty and homelessness. As an experiment of exploring possible solutions, the Construction Management program from the Lyles College of Engineering and the Department of Art and Design from the College of Arts & Humanities at California State University, Fresno, teamed with noted architect, Mr. Arthur Dyson through an interdisciplinary course in spring 2010, to design and build emergency housing for the homeless community in the Fresno area. The long-term vision was to create an Eco-Village model for the homeless that would support them to develop work skills in a safe, secure, and self-sustaining living environment. The Eco-Village course in spring 2010 was a pilot study for a two-semester design-build capstone course series the Construction Management program aims to develop in the long term. About 50 students from the two colleges worked in teams on design and construction of multiple proposed housing modules using various recycled and sustainable materials.

When compared to traditional trenched pipeline/pump station conveyance systems, tunneling provides significant triple bottom line advantages in all three categories of economics, environmental and social, including: a lower overall cost based on a 50-year present worth analysis, significantly reduced environmental and community impacts, elimination of energy costs for gravity flow systems, and preservation of surface space for future generations. Alongside these advantages, the sustainable benefits of a gravity tunnel system can be magnified by incorporating additional design elements. These elements include reuse of excavated materials, multi-use of the excavation for installation of additional utilities, installation of heat exchange systems in tunnel shafts, and use of industrial byproducts as cement substitutes to reduce the carbon footprint of construction.

The gradual increase in private mobility, dating back to the second half of the last century in western countries, especially in Italy, has caused the shutdown of several secondary railway lines which are rarely used and therefore little profitable to any institution, either owner or manager. Today the disused road patrimony can be functionally upgraded through conversion of railways into greenways dedicated to the so-called "soft mobility" (i.e. walking and cycling routes), thanks to the following features: i) separation of railway sediment from the ordinary road network; ii) reduced number of intersections with the road network; iii) moderate longitudinal slopes, generally less than 35߮; iv) long straight roads and large horizontal radii; v) width compatibility between the railway platform and that for cyclists and pedestrians; vi) interconnection between urban centres and routes passing often through areas of great natural value, hardly accessible by alternative modes of transport; vii) link with other public transport services. Moreover, since the majority of the disused railway infrastructures is publicly owned, the community is as a rule inclined to accept their conversion into greenways. In some Italian regions, such as Basilicata, Sicily and Sardinia, narrow-gauge railway lines (950 mm) were in the past highly used for orographic, economic and technical reasons, but they are now completely obsolete; a real greenway network can well be built in such contexts. With reference to Sicily, narrow-gauge lines covered approximately 811 km, of which 563 km have been managed by national railways and 248 km given to private companies since 1905. In the light of such potential, on 6 June 2006 the Sicilian Region issued a city council decree on the non-motorized mobility in Sicily, later enforced, as regards the conversion of railway sediments into greenways, by implementing the regional strategic plan for soft and/or non-motorized mobility, i.e. cycle and pedestrian routes called greenways (year 2009); the plan provided for approximately 16.5 million euros to be called for tenders in order to finance the realization of "main", "secondary" and "dedicated" suburban greenways. In this paper, after briefly reviewing the main international and Italian experiences in upgrading old disused railways and after examining some environmental issues closely linked to their construction, we indicate the major design standards and the technical measures required to make their plano-altimetric geometry in line with the national and international technical design standards for cycle tracks.

The project choices to design and manage a transport infrastructure system are extremely hard in thinly populated areas like, for instance, protected areas and mostly parks. In actual fact, the need for promotion and development of these areas, often characterized by large surfaces, contrasts with the necessity to preserve their inestimable natural value. The transportation demand in extremely sensible environmental contexts can be satisfied by providing incentives to use reduced-impact means of transport, regulating adequately the vehicle traffic flow and promoting the intermodality between private and public transport systems. Apart from performing their own traditional functions, these systems can become an effective aid to the valorization of protected areas and, sometimes, even a tourist attraction; this potential has especially been shown by some Guided Transport Systems which are already in operation in some Italian national parks. In the light of these experiences, in this paper we illustrate a case study on the improvement of mobility in a park area, showing a comparative analysis carried out among different modes of public transport and focusing on the potential transport, socioeconomic and environmental effects. Among the transport systems examined, some have been singled out because they are suited to be used in the short- to mediumterm (like the purchase of a fleet of electric shuttle buses for residential users and tourists), in that they are complementary to the multiple actions aiming at promoting the socioeconomic growth of the territory; whereas others can be realized in the long term when the said growth emerges as a concrete reality. In this context, one of the public mass transport systems which most suits the needs of the park under study is the "rubber tyre tram" (TVR). This is because the tram carriages equipped with tyres generally guarantee very high kinematic performances, good compatibility with winding tracks with steep longitudinal slopes (even higher than 13%), no air pollutant emissions and very moderate acoustic emissions. Therefore, the primary goal of this paper is to examine the techno-economic feasibility and the environmental compatibility between the "rubber tyre tram" - a mode of transport generally used in urban areas - and the case of parks and areas protected for their natural and environmental value.

Landscape fragmentation is the phenomenon of breaking up natural areas into smaller, more isolated units. The present work describes a methodology for evaluating the impact of both new and pre-existing transportation infrastructures by means of land cover maps. It enables quantifying the "pressure" on natural areas in terms of any further reduction in suitable habitat units based on the type of infrastructure and land cover elements. The proposed Infrastructural Fragmentation Index (IFI) assesses landscape fragmentation, taking into account both the number and connectivity of natural areas, which are rendered in clusters. The effects of defragmentation measures, such as wildlife crossings, are evaluated in terms of the consequent reduction in the pressure from the infrastructure. A case study has been analyzed in order to evaluate the fragmentation effects due to a new motorway in Lombardy (Italy), using CLC2000 and a GIS. Three scenarios have been studied: in the absence of the new infrastructure, and in its presence without and with the addition of wildlife crossings.

Road networks and transportation infrastructures are essential to assure accessibility and social and economic development of a country. For this reason it is necessary to protect them from calamitous events. The vulnerability assessment of a road network is one of the three fundamental steps towards a comprehensive definition of risk. The concept of vulnerability has not yet been unambiguously defined and it is possible to find different approaches and methodologies applied in studying it. The paper develops a careful analysis of previous researches concerning road network vulnerability and it shows how accessibility indicators can be used to assess road network vulnerability. Furthermore, these indicators can be useful to road administrators in deciding the priority of interventions and limiting the consequences of link or network section failures due to natural or anthropic hazards.

Transport infrastructures are fundamental in assuring accessibility in a country and encouraging economic and social development. A transport system often results extremely vulnerable to disasters caused by natural or human events. The assessment of risk of a transport network is a wide and relatively new field of research: vulnerability assessment of a transport network is part of it. Starting with a brief introduction on recent studies in this field, the paper illustrates a methodology and an index for assessing the vulnerability of links of a road network due to natural hazards. The index is the sum of two indicators which take into account the territorial consequences caused by a link failure and the possibility that this link may have to be used during rescue operations. In the conclusion the analytical approach and the vulnerability index are applied to an existing road network located in Sardinia (Italy), and compared with others present in literature.

The paper discusses the mechanisms based on visual stimuli that influence driver behavior and, subsequently, vehicle speed and trajectory. Road layout (i.e. the alternation of curves and tangents) must be designed in regard to a correct perception of the perspective sight. In order to consider the road from this point of view, experimental surveys have been conducted in a virtual environment (driving simulator), where real layouts have been reproduced and submitted to changes in their geometry (radii, tangent length, etc). Driver reaction in different environments has been monitored. Attention was particularly paid to the vehicular speed (always higher than the legal speed), because this parameter modifies the sight and hides layout variations, inducing a poor understanding of the limits of the occupied lane. The driving simulator proved to be a tool that can be used for the laboratory reproduction of risk situations.

Traditionally, serviceability surveys are conducted periodically through visual inspection of pavements in order to identify and classify any existing distress. Though such ratings may be subjective in nature, they are very useful for project level surveys or when technical or funding limitations arise. Many authorities and organisations have devised methods and equipment to objectively measure pavement surface conditions. The latest developments in this field include the use of laser scanners and video imaging technologies. Such techniques allow for determining the geometric characteristics of the distress and its position in an ‘absolute' reference system, taking into account the precision of the measurements performed. A standardised index obtained by combining various types of distress is useful when drafting priority maintenance lists for specific road sections. A semi-automatic method has been tested on various sites and validated by comparing the results obtained with those from standard manual calculation of the index.

Road safety management may be improved if quantitative assessment of safety levels is carried out. One of the most frequent roadway characteristics that affect crashes is the geometric alignment. Many highway design standards in the world have introduced rules to assess the alignment consistency. In this paper we report an experimental analysis conducted in 2010 on statistically significant number of roadway sections belonging to two - lane rural highways in Northern Italy. The aim of this research is to develop operating speed prediction models on tangents and circular curves. Acquired relationships were particularly interesting and different explanatory variables were introduced in the predictive models which are dependent on examined geometric roads features. These relationships constitute a new set of models about the operating speeds to design and verify geometric highways alignments adding to those already available in the scientific literature.

The design of urban road intersections always requires many activities, in order to analyse the technical aims of the project, as well as the environmental and architectural context. The choice of the optimal solution should be the result of a complex, well organised and optimized process. Updated techniques, devices and software are available nowadays, to integrate all the involved aspects. The proposed case study concerns an urban road intersection in the territory of Orte (VT, Italy), whose best geometrical and functional design solution has been defined using various tools, which mainly allow: (1) the three-dimensional geometrical modeling of the layout and road elements; (2) visualization, also with dynamic scenes; (3) functional analysis of traffic flows (traffic micro-simulation techniques).