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The Contractor's Self-Perceived Role in Sustainable Construction: Survey Results

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The paper was written for the International Group for Lean Construction Conference in July 2013 in Fortaleza, Brazil.

With the advent of sustainable building ordinances in the United States and internationally,

The paper was written for the International Group for Lean Construction Conference in July 2013 in Fortaleza, Brazil.

With the advent of sustainable building ordinances in the United States and internationally, contractors are required to deliver sustainable projects but have historically not been considered partners in developing the sustainability goals and objectives for projects. Additionally, as alternative project delivery methods gain popularity, contractors have an opportunity and—in an increasing number of cases—a requirement, to take a larger role in sustainability efforts beyond the design phase. Understanding the contractor’s self-perceived role in this industry is imperative to informing their future role in the sustainable construction industry. This paper presents data and analysis of a survey of general contractors in the Phoenix, Arizona market that asked for their opinions and viewpoints regarding sustainable construction. Respondents provided feedback about corporate profitability, growth forecast, and the perceived efficiency of the U.S Green Building Council’s LEED rating system. The survey also queried contractors about current and future work breakdown structures for sustainable project delivery as well as their underlying motives for involvement in these projects.
Academics from Arizona State University worked with local industry to develop the survey in 2012 and the survey was deployed in 2013. We sent the survey to 76 contractors and received responses from 21, representing a 27.6% response rate. Respondents include representatives from general contractors, mechanical contractors, and electrical contractors, among others. This paper presents the responses from general contractors as they typically have most contact with the owner and design teams.

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  • 2013-05

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The Nexus of Lean and Green Construction

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Lean and Green construction methodologies are prevalent in today's construction industry. Green construction implementation in buildings has progressed quickly due to the popularity and development of building rating systems, such

Lean and Green construction methodologies are prevalent in today's construction industry. Green construction implementation in buildings has progressed quickly due to the popularity and development of building rating systems, such as LEED, Green Globes, and the Living Building Challenge. Similarly, lean construction has become more popular as this philosophy often leads to efficient construction and improved owner satisfaction. Green construction is defined as using sustainable materials in the construction process to eliminate environmental degradation and ensure that material and equipment use aligns with the design intent and promotes efficient building performance. Lean construction is defined as a set of operational/systematic processes that reduce waste and eliminates defects in the project process throughout its lifecycle. This paper describes the implementation of Lean and Green construction processes to determine the trends that each methodology contributes to a project as well as how these methodologies synergize. The authors identified common elements of each methodology through semi-structured interviews with several construction industry professionals who had extensive experience with lean and green construction. Interviewees report lean and green construction philosophies are different "flavors" of the industry; however, interviewees also state if implemented together, these processes often result in a high-performance building.

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  • 2015-05

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A finite element-based framework for understanding the energy performance of concrete elements incorporating phase change materials

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Dwindling energy resources and associated environmental costs have resulted in a serious need to design and construct energy efficient buildings. One of the strategies to develop energy efficient structural materials

Dwindling energy resources and associated environmental costs have resulted in a serious need to design and construct energy efficient buildings. One of the strategies to develop energy efficient structural materials is through the incorporation of phase change materials (PCM) in the host matrix. This research work presents details of a finite element-based framework that is used to study the thermal performance of structural precast concrete wall elements with and without a layer of phase change material. The simulation platform developed can be implemented for a wide variety of input parameters. In this study, two different locations in the continental United States, representing different ambient temperature conditions (corresponding to hot, cold and typical days of the year) are studied. Two different types of concrete - normal weight and lightweight, different PCM types, gypsum wallboard's with varying PCM percentages and different PCM layer thicknesses are also considered with an aim of understanding the energy flow across the wall member. Effect of changing PCM location and prolonged thermal loading are also studied. The temperature of the inside face of the wall and energy flow through the inside face of the wall, which determines the indoor HVAC energy consumption are used as the defining parameters. An ad-hoc optimization scheme is also implemented where the PCM thickness is fixed but its location and properties are varied. Numerical results show that energy savings are possible with small changes in baseline values, facilitating appropriate material design for desired characteristics.

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Date Created
  • 2012

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Toward a "green" organ: organ building and sustainability

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This study examines the effectiveness of various types of alternative resources in organ building in order to determine whether a change to more sustainable materials would benefit or hinder the

This study examines the effectiveness of various types of alternative resources in organ building in order to determine whether a change to more sustainable materials would benefit or hinder the overall sound production of the instrument. The qualities of the metals and woods currently used in organ production (e.g. lead, walnut, etc.) have been prized for centuries, so the substitution of different, more sustainable materials must be considered with regards to the sonic alterations, as well as the financial implications, of using alternatives to make the organ more “green.”

Five organ builders were interviewed regarding their views on sustainable materials. In addition, the author consulted the websites of nine national and four international organ builders for information about sustainability, indicating that each organ builder defines the term somewhat differently. Decisions on the woods and metals to be used in building or refurbishing an existing organ are based more on the visual appearance, the sound desired, and the potential for reuse of existing materials. A number of sustainability practices are currently in use by organ builders in the United States and Europe. These include the reuse of transportation boxes, efforts towards recycled metal and wood pipework, and the use of high efficiency lighting.

The investigations into sustainable practice that are presented here document a variety of approaches to sustainability in organ building in the United States, Canada and Europe. This research should assist in the evaluation of further efforts to conserve valuable resources while ensuring the high quality of sound that has characterized the organ throughout its long history.

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Date Created
  • 2014

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The optimized use of phase change materials in buildings

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In recent years, 40% of the total world energy consumption and greenhouse gas emissions is because of buildings. Out of that 60% of building energy consumption is due to HVAC

In recent years, 40% of the total world energy consumption and greenhouse gas emissions is because of buildings. Out of that 60% of building energy consumption is due to HVAC systems. Under current trends these values will increase in coming years. So, it is important to identify passive cooling or heating technologies to meet this need. The concept of thermal energy storage (TES), as noted by many authors, is a promising way to rectify indoor temperature fluctuations. Due to its high energy density and the use of latent energy, Phase Change Materials (PCMs) are an efficient choice to use as TES. A question that has not satisfactorily been addressed, however, is the optimum location of PCM. In other words, given a constant PCM mass, where is the best location for it in a building? This thesis addresses this question by positioning PCM to obtain maximum energy savings and peak time delay. This study is divided into three parts. The first part is to understand the thermal behavior of building surfaces, using EnergyPlus software. For analysis, a commercial prototype building model for a small office in Phoenix, provided by the U.S. Department of Energy, is applied and the weather location file for Phoenix, Arizona is also used. The second part is to justify the best location, which is obtained from EnergyPlus, using a transient grey box building model. For that we have developed a Resistance-Capacitance (RC) thermal network and studied the thermal profile of a building in Phoenix. The final part is to find the best location for PCMs in buildings using EnergyPlus software. In this part, the mass of PCM used in each location remains unchanged. This part also includes the impact of the PCM mass on the optimized location and how the peak shift varies. From the analysis, it is observed that the ceiling is the best location to install PCM for yielding the maximum reduction in HVAC energy consumption for a hot, arid climate like Phoenix.

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Date Created
  • 2018

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Evaluation of emerging sustainable residential construction technologies in the Twin Cities Metro Area

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The intent of this study was to identify the most viable among a proposive sample of emerging sustainable construction technologies with respect to the Twin Cities Metropolitan Geographic Area. With

The intent of this study was to identify the most viable among a proposive sample of emerging sustainable construction technologies with respect to the Twin Cities Metropolitan Geographic Area. With space heating and space cooling accounting for such a significant portion of energy consumption in Twin Cities homes, a representative sample of homes was analyzed for annual heating and cooling loads. For each home a series of heating, ventilation, air conditioning (HVAC) and envelope equipment was modeled in order to provide data for various sustainable home construction technologies. The result was a specific amount of energy savings from baseline construction methods for each sustainable technology. The study found that integrated geothermal heat pump and radiant conditioning systems have a far greater impact on energy savings than the construction methods evaluated. Nevertheless, insulated concrete forms provided the greatest energy savings within the proposive set of construction methods. The greatest amount of space conditioning energy savings of all configurations tested was 73.48% using an integrated geothermal heat pump and radiant conditioning system, structural insulated panel wall construction, aerosol air infiltration prevention, and insulated concrete form basement construction. The results of the study were used to determine areas for further research and to provide awareness within the Twin Cities construction enterprise to determine the most viable technologies that contractors, municipalities, and citizens should prioritize moving forward.

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  • 2019

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Carbonate mineral precipitation for soil improvement through microbial denitrification

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Microbially induced calcium carbonate precipitation (MICP) is attracting increasing attention as a sustainable means of soil improvement. While there are several possible MICP mechanisms, microbial denitrification has the potential to

Microbially induced calcium carbonate precipitation (MICP) is attracting increasing attention as a sustainable means of soil improvement. While there are several possible MICP mechanisms, microbial denitrification has the potential to become one of the preferred methods for MICP because complete denitrification does not produce toxic byproducts, readily occurs under anoxic conditions, and potentially has a greater carbonate yield per mole of organic electron donor than other MICP processes. Denitrification may be preferable to ureolytic hydrolysis, the MICP process explored most extensively to date, as the byproduct of denitrification is benign nitrogen gas, while the chemical pathways involved in hydrolytic ureolysis processes produce undesirable and potentially toxic byproducts such as ammonium (NH4+). This thesis focuses on bacterial denitrification and presents preliminary results of bench-scale laboratory experiments on denitrification as a candidate calcium carbonate precipitation mechanism. The bench-scale bioreactor and column tests, conducted using the facultative anaerobic bacterium Pseudomonas denitrificans, show that calcite can be precipitated from calcium-rich pore water using denitrification. Experiments also explore the potential for reducing environmental impacts and lowering costs associated with denitrification by reducing the total dissolved solids in the reactors and columns, optimizing the chemical matrix, and addressing the loss of free calcium in the form of calcium phosphate precipitate from the pore fluid. The potential for using MICP to sequester radionuclides and metal contaminants that are migrating in groundwater is also investigated. In the sequestration process, divalent cations and radionuclides are incorporated into the calcite structure via substitution, forming low-strontium calcium carbonate minerals that resist dissolution at a level similar to that of calcite. Work by others using the bacterium Sporosarcina pasteurii has suggested that in-situ sequestration of radionuclides and metal contaminants can be achieved through MICP via hydrolytic ureolysis. MICP through bacterial denitrification seems particularly promising as a means for sequestering radionuclides and metal contaminants in anoxic environments due to the anaerobic nature of the process and the ubiquity of denitrifying bacteria in the subsurface.

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Date Created
  • 2013