Liquid polymers(LP)have become an important structural material used in the construction industry in the last decade.This paper investigates the viability of using commercially available LPs as a coating materia...Liquid polymers(LP)have become an important structural material used in the construction industry in the last decade.This paper investigates the viability of using commercially available LPs as a coating material to improve the flexural strength of fiber-modified concrete beams.The scope included preparing rectangular prism concrete beams with a concrete mixture including fly ash and fiber and coating them with four different liquid polymers at a uniform thickness following the curing process while one set of samples was maintained under the same conditions as a control group without coating.In addition,cylindrical samples were prepared to determine the compressive strength of the concrete mixture.Following the curing process in an unconfined open-air laboratory environment for another 28 days,concrete samples were tested to determine the flexural strength and deflection characteristics under center point loading equipment.The results revealed that all four coating types enhanced both the flexural strength and the average maximum deflection of the beams compared to the control group.While the enhancement in the flexural strength changed approximately between 5%and 36%depending on the coating type,the improvements in average maximum deflections varied between 3.7%and 28.4%.展开更多
The author discusses the application of System Dynamics to high-level strategic simulation in construction. In particular, System Dynamics' strength on representing feedback processes, aggregation, soft variables,...The author discusses the application of System Dynamics to high-level strategic simulation in construction. In particular, System Dynamics' strength on representing feedback processes, aggregation, soft variables,and continuous simulation clock for high-level simulation are discussed using real modeling examples. From this exercise, it is concluded that System Dynamics offers a great potential for strategic simulation in construction.Further, the author proposes a comprehensive simulation framework that integrates System Dynamics and Discrete Event Simulation for a strategic decision making process in construction where operational details should be taken into account.展开更多
The utility poles of an electric power distribution system are frequently damaged by wind-related disasters.This study notes that the wooden poles are particularly vulnerable to such disasters and the failures of the ...The utility poles of an electric power distribution system are frequently damaged by wind-related disasters.This study notes that the wooden poles are particularly vulnerable to such disasters and the failures of the poles can cause a network-level failure leading to short-or longterm power outages. To mitigate the problem, this study proposes a framework for measuring the resilience of the wooden utility poles based on the angular deflection of a pole due to the wind force. Given the existing inclination angle of a pole, the angular deflection is measured by finite element analysis using ANSYS~? Workbench^1 to determine the resilience area under various wind speeds. For this, the conditions of load and support for a pole, which are called boundary conditions in ANSYS~?, are generated. The proposed framework also includes an approach to cost–benefit analysis that compares different strategies for corrective action. The results of the case study in which the framework was applied show that the proposed framework can be effectively utilized by electric power distribution companies to increase the resilience of their systems.展开更多
The utility poles of electric power distribution lines are very vulnerable to many natural hazards, while power outages due to pole failures can lead to adverse economic and social consequences. Utility companies,ther...The utility poles of electric power distribution lines are very vulnerable to many natural hazards, while power outages due to pole failures can lead to adverse economic and social consequences. Utility companies,therefore, need to monitor the conditions of poles regularly and predict their future conditions accurately and promptly to operate the distribution system continuously and safely.This article presents a novel pole monitoring method that uses state-of-the-art deep learning and computer vision methods to meet the need. The proposed method automatically captures the current pole inclination angles using an unmanned aerial vehicle. The method calculates the bending moment exerted on the poles due to wind and gravitational forces, as well as cable weight, to compare it with the moment of rupture. The method also includes a machine learning-based model that is built by using a support vector machine to predict the resilience conditions of a pole after a wind event in a faster manner. The three modules of the proposed method are effective tools to classify pole conditions and are expected to enable utility companies to increase the resilience of their systems.展开更多
The need for safe operation and effective maintenance of pipelines grows as oil and gas demand rises.Thereby,it is increasingly imperative to monitor and inspect the pipeline system,detect causes contributing to devel...The need for safe operation and effective maintenance of pipelines grows as oil and gas demand rises.Thereby,it is increasingly imperative to monitor and inspect the pipeline system,detect causes contributing to developing pipeline damage,and perform preventive maintenance in a timely manner.Currently,pipeline inspection is performed at pre-determined intervals of several months,which is not sufficiently robust in terms of timeliness.This research proposes a drone and artificial intelligence reconsolidated technological solution(DARTS) by integrating drone technology and deep learning technique.This solution is aimed to detect the targeted potential root problems-pipes out of alignment and deterioration of pipe support system-that can cause critical pipeline failures and predict the progress of the detected problems by collecting and analyzing image data periodically.The test results show that DARTS can be effectively used to support decision making for preventive pipeline maintenance to increase pipeline system s afety and resilience.展开更多
Sustainable practices in the built environment are becoming a more common phenomona as market penetration of green buildings grow. Despite the reported benefits of green buildings, barriers to sustainability still exi...Sustainable practices in the built environment are becoming a more common phenomona as market penetration of green buildings grow. Despite the reported benefits of green buildings, barriers to sustainability still exist. To motivate wider adoption of sustainable built environments, this research studies public policy and its impacts. The study aims to understand the links between public policy, construction playmakers’ (e.g., organizations’, institutions’, business owners’, and developers’) motivation to build green, and growth of sustainable built environments in the United States. As a step forward in this direction, this paper focuses on the case of Michigan and explores construction playmakers’ motivations to build and/or occupy sustainable buildings and how effective current public policy in Michigan is at addressing these motivations.There is little research on the links among legislation, construction playmakers’ motivation to build green, and the growth of sustainable built environment in the United States. This article’s findings show that: 1) green building costs are still the most frequently-reported barrier to green building, 2) property developers are significantly less likely to utilize green building practices than other construction playmakers, 3) single-family residential buildings were the least likely building type to receive green certifications, and 4) construction playmakers report low levels of green policy awareness and use despite the presence of relevant public policies. These findings will provide direction for policy makers and advocates in creating policy that will effectively promote green building construction.展开更多
The energy performance of an existing building is the amount of energy consumed to meet various needs associated with the standardized use of a building and is reflected in one or more indicators known as Building Ene...The energy performance of an existing building is the amount of energy consumed to meet various needs associated with the standardized use of a building and is reflected in one or more indicators known as Building Energy Performance Indicators(EnPIs).These indicators are distributed amongst six main factors influencing energy consumption:climate,building envelope,building services and energy systems,building operation and maintenance,occupants’activities and behaviour,and indoor environmental quality.Any improvement made to either the existing structure or the physical and operational upgrade of a building system that enhances energy performance is considered an energy efficiency retrofit.The main goal of this research is to support the implementation of multifamily residential building energy retrofits through expert knowledge consensus on EnPIs for energy efficiency retrofit planning.The research methodology consists of a comprehensive literature review which has identified 35 EnPIs for assessing performance of existing residential buildings,followed by a ranking questionnaire survey of experts in the built-environment to arrive at a priority listing of indicators based on mean rank.This was followed by concordance analysis and measure of standard deviation.A total of 280 experts were contacted globally for the survey,and 106 completed responses were received resulting in a 37.85%response rate.The respondents were divided into two groups for analysis:academician/researchers and industry practitioners.The primary outcome of the research is a priority listing of EnPIs based on the quantitative data from the knowledge-base of experts from these two groups.It is the outcome of their perceptions of retrofitting factors and corresponding indicators.A retrofit strategy consists of five phases for retrofitting planning in which the second phase comprises an energy audit and performance assessment and diagnostics.This research substantiates the performance assessment process through the identification of EnPIs.展开更多
文摘Liquid polymers(LP)have become an important structural material used in the construction industry in the last decade.This paper investigates the viability of using commercially available LPs as a coating material to improve the flexural strength of fiber-modified concrete beams.The scope included preparing rectangular prism concrete beams with a concrete mixture including fly ash and fiber and coating them with four different liquid polymers at a uniform thickness following the curing process while one set of samples was maintained under the same conditions as a control group without coating.In addition,cylindrical samples were prepared to determine the compressive strength of the concrete mixture.Following the curing process in an unconfined open-air laboratory environment for another 28 days,concrete samples were tested to determine the flexural strength and deflection characteristics under center point loading equipment.The results revealed that all four coating types enhanced both the flexural strength and the average maximum deflection of the beams compared to the control group.While the enhancement in the flexural strength changed approximately between 5%and 36%depending on the coating type,the improvements in average maximum deflections varied between 3.7%and 28.4%.
文摘The author discusses the application of System Dynamics to high-level strategic simulation in construction. In particular, System Dynamics' strength on representing feedback processes, aggregation, soft variables,and continuous simulation clock for high-level simulation are discussed using real modeling examples. From this exercise, it is concluded that System Dynamics offers a great potential for strategic simulation in construction.Further, the author proposes a comprehensive simulation framework that integrates System Dynamics and Discrete Event Simulation for a strategic decision making process in construction where operational details should be taken into account.
文摘The utility poles of an electric power distribution system are frequently damaged by wind-related disasters.This study notes that the wooden poles are particularly vulnerable to such disasters and the failures of the poles can cause a network-level failure leading to short-or longterm power outages. To mitigate the problem, this study proposes a framework for measuring the resilience of the wooden utility poles based on the angular deflection of a pole due to the wind force. Given the existing inclination angle of a pole, the angular deflection is measured by finite element analysis using ANSYS~? Workbench^1 to determine the resilience area under various wind speeds. For this, the conditions of load and support for a pole, which are called boundary conditions in ANSYS~?, are generated. The proposed framework also includes an approach to cost–benefit analysis that compares different strategies for corrective action. The results of the case study in which the framework was applied show that the proposed framework can be effectively utilized by electric power distribution companies to increase the resilience of their systems.
文摘The utility poles of electric power distribution lines are very vulnerable to many natural hazards, while power outages due to pole failures can lead to adverse economic and social consequences. Utility companies,therefore, need to monitor the conditions of poles regularly and predict their future conditions accurately and promptly to operate the distribution system continuously and safely.This article presents a novel pole monitoring method that uses state-of-the-art deep learning and computer vision methods to meet the need. The proposed method automatically captures the current pole inclination angles using an unmanned aerial vehicle. The method calculates the bending moment exerted on the poles due to wind and gravitational forces, as well as cable weight, to compare it with the moment of rupture. The method also includes a machine learning-based model that is built by using a support vector machine to predict the resilience conditions of a pole after a wind event in a faster manner. The three modules of the proposed method are effective tools to classify pole conditions and are expected to enable utility companies to increase the resilience of their systems.
基金This project was partially supported by the Center for Midstream and Management Science at Lamar University,Beaumont,Texas,USA.
文摘The need for safe operation and effective maintenance of pipelines grows as oil and gas demand rises.Thereby,it is increasingly imperative to monitor and inspect the pipeline system,detect causes contributing to developing pipeline damage,and perform preventive maintenance in a timely manner.Currently,pipeline inspection is performed at pre-determined intervals of several months,which is not sufficiently robust in terms of timeliness.This research proposes a drone and artificial intelligence reconsolidated technological solution(DARTS) by integrating drone technology and deep learning technique.This solution is aimed to detect the targeted potential root problems-pipes out of alignment and deterioration of pipe support system-that can cause critical pipeline failures and predict the progress of the detected problems by collecting and analyzing image data periodically.The test results show that DARTS can be effectively used to support decision making for preventive pipeline maintenance to increase pipeline system s afety and resilience.
文摘Sustainable practices in the built environment are becoming a more common phenomona as market penetration of green buildings grow. Despite the reported benefits of green buildings, barriers to sustainability still exist. To motivate wider adoption of sustainable built environments, this research studies public policy and its impacts. The study aims to understand the links between public policy, construction playmakers’ (e.g., organizations’, institutions’, business owners’, and developers’) motivation to build green, and growth of sustainable built environments in the United States. As a step forward in this direction, this paper focuses on the case of Michigan and explores construction playmakers’ motivations to build and/or occupy sustainable buildings and how effective current public policy in Michigan is at addressing these motivations.There is little research on the links among legislation, construction playmakers’ motivation to build green, and the growth of sustainable built environment in the United States. This article’s findings show that: 1) green building costs are still the most frequently-reported barrier to green building, 2) property developers are significantly less likely to utilize green building practices than other construction playmakers, 3) single-family residential buildings were the least likely building type to receive green certifications, and 4) construction playmakers report low levels of green policy awareness and use despite the presence of relevant public policies. These findings will provide direction for policy makers and advocates in creating policy that will effectively promote green building construction.
文摘The energy performance of an existing building is the amount of energy consumed to meet various needs associated with the standardized use of a building and is reflected in one or more indicators known as Building Energy Performance Indicators(EnPIs).These indicators are distributed amongst six main factors influencing energy consumption:climate,building envelope,building services and energy systems,building operation and maintenance,occupants’activities and behaviour,and indoor environmental quality.Any improvement made to either the existing structure or the physical and operational upgrade of a building system that enhances energy performance is considered an energy efficiency retrofit.The main goal of this research is to support the implementation of multifamily residential building energy retrofits through expert knowledge consensus on EnPIs for energy efficiency retrofit planning.The research methodology consists of a comprehensive literature review which has identified 35 EnPIs for assessing performance of existing residential buildings,followed by a ranking questionnaire survey of experts in the built-environment to arrive at a priority listing of indicators based on mean rank.This was followed by concordance analysis and measure of standard deviation.A total of 280 experts were contacted globally for the survey,and 106 completed responses were received resulting in a 37.85%response rate.The respondents were divided into two groups for analysis:academician/researchers and industry practitioners.The primary outcome of the research is a priority listing of EnPIs based on the quantitative data from the knowledge-base of experts from these two groups.It is the outcome of their perceptions of retrofitting factors and corresponding indicators.A retrofit strategy consists of five phases for retrofitting planning in which the second phase comprises an energy audit and performance assessment and diagnostics.This research substantiates the performance assessment process through the identification of EnPIs.
