Nemati, Kamran M.; Uhlmeyer, Jeff S. (2021). Accelerated Construction of Urban Intersections with Portland Cement Concrete Pavement (PCCP). Case Studies In Construction Materials, 14.
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Abstract
The frequent maintenance required on asphalt concrete (AC) pavement sections has made reconstruction with portland cement concrete pavement (PCCP) a feasible alternative. However, many constructability issues need to be addressed in order to realize the full potential of this alternative. Accelerated paving encompasses three classes of activities: methods to accelerate the rate of strength gain, methods to minimize the construction time, and traffic control strategies to minimize user delay. In this paper a case study will be presented in which an AC intersection was reconstructed with portland cement concrete pavement. The entire reconstruction of the intersection, including demolition of the AC pavement and its replacement with PCCP, took place over a period of three days, starting on Thursday evening and opening the intersection to the traffic on Sunday afternoon. This paper documents this effort in order to provide practitioners additional options for rapid reconstruction of urban intersections and includes documentation of the construction process, traffic management strategies, and an analysis of the costs. The results of this investigation can be used to educate pavement construction professionals and the academic community on the use of PCCP for accelerated reconstruction of major urban intersections with minimal user and traffic disruption, using innovative construction techniques and traffic management optimization principles. This investigation produced valuable information to demonstrate that concrete pavements can be constructed efficiently and quickly. (C) 2021 The Authors. Published by Elsevier Ltd.
Keywords
Concrete; Accelerated Construction; Pavement; Portland Cement Concrete Pavement; Maturity Method
Wang, Lan; Zhang, Surong; Yang, Zilin; Zhao, Ziyu; Moudon, Anne Vernez; Feng, Huasen; Liang, Junhao; Sun, Wenyao; Cao, Buyang. (2021). What County-level Factors Influence Covid-19 Incidence in the United States? Findings from the First Wave of the Pandemic. Cities, 118.
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Abstract
Effective control of the COVID-19 pandemic via appropriate management of the built environment is an urgent issue. This study develops a research framework to explore the relationship between COVID-19 incidence and influential factors related to protection of vulnerable populations, intervention in transmission pathways, and provision of healthcare resources. Relevant data for regression analysis and structural equation modeling is collected during the first wave of the pandemic in the United States, from counties with over 100 confirmed cases. In addition to confirming certain factors found in the existing literature, we uncover six new factors significantly associated with COVID-19 incidence. Furthermore, incidence during the lockdown is found to significantly affect incidence after the reopening, highlighting that timely quarantining and treating of patients is essential to avoid the snowballing transmission over time. These findings suggest ways to mitigate the negative effects of subsequent waves of the pandemic, such as special attention of infection prevention in neighborhoods with unsanitary and overcrowded housing, minimization of social activities organized by neighborhood associations, and contactless home delivery service of healthy food. Also worth noting is the need to provide support to people less capable of complying with the stay-at-home order because of their occupations or socio-economic disadvantage.
Keywords
Pandemics; Covid-19; Covid-19 Pandemic; Infection Prevention; Stay-at-home Orders; Structural Equation Modeling; United States; Communicable Disease Prevention; Influential Factors; Lockdown; Structural Equation Modeling (sem); Prevalence; Disease; Healthy Food; Social Activities; Counties; Neighborhoods; Housing; Built Environment; Prevention; Minimization; Socioeconomic Factors; Intervention; Health Care; Vulnerability; Occupations; Coronaviruses; Food Service; Disease Transmission; United States--us
Aziz, Ahmed M. Abdel. (2021). The Practice of Roadway Safety Management in Public-Private Partnerships. Journal Of Construction Engineering And Management, 147(12).
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Abstract
As a matter of course, the private party in public-private partnerships (PPPs) assumes the responsibility for roadway safety management (RSM). However, because most PPPs are performance-based, public highway agencies must articulate the specifications and methods they develop to enforce RSM practices. Despite the increased interest in PPPs in recent decades, little has been published on developing and propagating the RSM practices used with this delivery system. To fill this research gap and explore RSM practices in PPPs, this work took a synthesis research approach, using content analysis to critically review and analyze 16 PPP agreements in seven states and provinces leading in PPP contracting in North America. The study discovered several methods and organized them under five mechanisms: Mechanism 1, integrating roadway safety into project performance specifications and initiating new tools such as safety compliance orders; Mechanism 2, imposing nonconformance monetary deductions based on point and classification systems; Mechanism 3, regulating safety payments on the basis of crash statistics; Mechanism 4, promoting safety initiative programs; and Mechanism 5, enforcing administrative countermeasures such as work suspension and default/termination triggers for persistent developer noncompliance. Mechanisms 1 and 5 were the default mechanisms in all toll- and availability-based projects, whereas Mechanism 2 was common in availability-only projects. The research reviewed the RSM packages in the PPP agreements, elucidating the particulars of the RSM mechanisms, highlighting RSM design considerations, presenting implementation guidelines, and articulating research needs. The research results were validated against PPP highways in five other states and provinces. This synthesis research provides highway agencies with an extensive practice review to support RSM package design for future PPP projects.
Keywords
Qualitative Research; Incentives; Public-private Partnerships (ppps); Performance Specifications; Roadway Safety; Payment Mechanisms; Availability Payment; Highways
Firth, Caislin L.; Baquero, Barbara; Berney, Rachel; Hoerster, Katherine D.; Mooney, Stephen J.; Winters, Meghan. (2021). Not Quite a Block Party: Covid-19 Street Reallocation Programs in Seattle, WA and Vancouver, BC. Ssm-population Health, 14.
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Abstract
The COVID-19 pandemic has exposed mobility inequities within cities. In response, cities are rapidly implementing street reallocation initiatives. These interventions provide space for walking and cycling, however, other mobility needs (e.g., essential workers, deliveries) may be impeded by these reallocation decisions. Informed by mobility justice frameworks, we examined socio-spatial differences in access to street reallocations in Seattle, Washington and Vancouver, British Columbia. In both cities, more interventions occurred in areas where people of color, particularly Black and Indigenous people, lived. In Seattle, more interventions occurred in areas where people with disabilities, on food stamps, and children lived. In Vancouver, more interventions occurred in areas where recent immigrants lived, or where people used public transit or cycled to work. Street reallocations could be opportunities for cities to redress inequities in mobility and access to public spaces. Going forward, it is imperative to monitor how cities use data and welcome communities to redesign these temporary spaces to be corridors for their own mobility.
Keywords
Covid-19; Equity; Inequalities; Built Environment; Mobility; Cities; Mobility Justice
Parsaee, Mojtaba; Demers, Claude M. H.; Potvin, Andre; Lalonde, Jean-Francois; Inanici, Mehlika; Hebert, Marc. (2021). Biophilic Photobiological Adaptive Envelopes for Sub-Arctic Buildings: Exploring Impacts of Window Sizes and Shading Panels’ Color, Reflectance, and Configuration. Solar Energy, 220, 802 – 827.
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Abstract
Northern building envelopes must provide efficient indoor-outdoor connections based on photobiologicalpsychological needs of occupants for positive relationships with the sub-Arctic nature, particularly daylighting and day/night cycles. Envelope configurations of Northern Canada's buildings have not yet considered such requirements. Potentials of adaptive systems are also still limited. This research develops a fundamental model of adaptive multi-skin envelopes for sub-Arctic buildings based on main biophilic and photobiological indicators which characterize efficient indoor-outdoor connections. Biophilic indicators characterize the state of connections among occupants and outdoors which could stimulate biological-psychological responses. Photobiological indicators determine human-centric lighting adaptation scenarios for hourly lighting qualities and sufficient darkness in relation to local day/night cycles and daylighting. Biophilic performance of the proposed envelope was evaluated through 18 numerical models in terms of impacts of window and shading sizes on occupants' field of views. Photobiological lighting performance was evaluated by experimental methods using 23 physical models at 1:10 scale. Surface characteristics of dynamic shading panels, including color, reflectance, orientation, and inclination, were studied for potential photobiological impacts in terms of melanopic/photopic ratios and color temperatures. Results show that the proposed envelope could (i) offer acceptable direct visual connections with the outdoor nature through efficient window sizes for biophilia, and (ii) modify daylighting qualities to address hourly/seasonal photobiological needs of sub-Arctic occupants. Challenges of the proposed envelope to implement under sub-Arctic climatic conditions are underlined especially in terms of energy issues. The research outcomes help architects and decision-makers to improve occupants' wellbeing and healthy buildings in subArctic climates.
Keywords
Window Shades; Building Envelopes; Reflectance; Color Temperature; Daylighting; Building-integrated Photovoltaic Systems; Daylight; Outdoor Living Spaces; Canada; Adaptive Envelope; Arctic Climate; Biophilic Design; Healthy Building; Photobiological Lighting; Light; Exposure; Stress; Design; Architecture; Sensitivity; Illuminance; Environment; Melatonin; Recovery; Surface Properties; Performance Evaluation; Indicators; Polar Environments; Lighting; Shading; Darkness; Decision Making; Envelopes; Configurations; Buildings; Color; Adaptive Systems; Climatic Conditions; Numerical Models; Mathematical Models; Panels; Night; Climate; Orientation; Arctic Region
Wang, Yunhong; Lee, Hyun Woo; Tang, Wenzhe; Whittington, Jan; Qiang, Maoshan. (2021). Structural Equation Modeling for the Determinants of International Infrastructure Investment: Evidence from Chinese Contractors. Journal Of Management In Engineering, 37(4).
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Abstract
International infrastructure investment can effectively accelerate infrastructure development in developing countries and thus support their social and economic progress. However, little is known of the factors that may determine the flow of international infrastructure investment to those countries. This study aims to bridge that knowledge gap, first by identifying the determinants of international infrastructure investment, and then by developing a structural equation model to reveal their underlying interrelationships. The structural equation model is applied to country-level data regarding international infrastructure investment with Chinese contractors in 141 countries worldwide over the 9-year period from 2009 to 2017. The results show that three determinants, namely infrastructure quality, labor supply, and investment interdependency, have a positive relationship with a country's international infrastructure investment inflow. However, another determinant, institutional environment, has a significantly negative impact, which suggests that when making foreign infrastructure investment, Chinese contractors enter countries with a comparatively poor institutional environment with substantial political risks. The results also highlight how much a robust infrastructure development plan can help developing countries avoid the poor-infrastructure trap, a situation in which poor infrastructure quality discourages international infrastructure investment. These research findings may assist international infrastructure investment firms to make informed decisions with regard to financing and managing projects and help policymakers who focus on attracting foreign investment in infrastructure.
Keywords
Foreign Direct-investment; Public-private Partnerships; Economic-growth; Transport Infrastructure; Developing-countries; Labor Productivity; Fit Indexes; Location; Energy; Firms; Infrastructure Investment; Institutional Environment; Infrastructure Quality; Foreign Direct Investment (fdi) Interdependency; Structure Equation Modeling; Belt And Road Initiative