Alternative Solvent for Reducing Health and Environmental Hazards in Extracting Asphalt: An Evaluation

2000 ◽  
Vol 1712 (1) ◽  
pp. 79-85 ◽  
Author(s):  
Holly Collins-Garcia ◽  
Mang Tia ◽  
Reynaldo Roque ◽  
Bouzid Choubane
Keyword(s):  
Ozone Depletion ◽  
Asphalt Binders ◽  
Department Of Transportation ◽  
Control Programs ◽  
State Highway ◽  
Florida Department ◽  
Trade Name ◽  
Asphalt Paving ◽  
Environmentally Sound ◽  
State Highway Agencies

Trichloroethylene is a solvent currently used by the Florida Department of Transportation (FDOT) and many state highway agencies for separation of asphalt binders from asphalt paving mixtures in their quality control programs. However, it has been proved that trichloroethylene contributes to ozone depletion, and it is also known to be a carcinogen. The goal of the present study was to determine whether a more environmentally sound and less hazardous solvent could be used for this purpose. The solvent investigated is an n-propyl bromide with the trade name EnSolv. Preliminary studies show that it is safer than many other solvents available today. The study was performed to determine whether EnSolv could be a substitute for trichloroethylene without changing current testing methods. The tests performed included the asphalt solubility test, extraction and recovery of asphalt binders from mixtures, and penetration and viscosity tests with the recovered binders. The results of the study showed that EnSolv could be a suitable replacement for trichloroethylene. In addition, EnSolv could also be recycled and reused in the extraction and recovery procedures.

Determining Minimum Contract Time for Highway Projects

2000 ◽  
Vol 1712 (1) ◽  
pp. 196-201 ◽  
Author(s):  
Jin-Fang Shr ◽  
Benjamin P. Thompson ◽  
Jeffrey S. Russell ◽  
Bin Ran ◽  
H. Ping Tserng
Keyword(s):  
Low Cost ◽  
Road User ◽  
User Cost ◽  
Time Curve ◽  
Highway Projects ◽  
The Road ◽  
State Highway ◽  
Florida Department ◽  
The Cost ◽  
State Highway Agencies

An increasing number of state highway agencies (SHAs) are using A (cost) + B (time cost) bidding ( A + B bidding) for highway construction. The A + B bidding concept is designed to shorten the total contract time by allowing each contractor to bid the number of days in which the work can be accomplished, in addition to the traditional cost bid. The SHA is then presented with the problem of determining a reasonable range of contract time submitted by the bidders. Most SHAs do not currently restrict the range of B. However, several problems may arise from an unrestricted range of B. First, if no minimum is set for B, a bidder may inflate the cost bid and submit an unreasonably low B, using the excess cost bid to cover the disincentives charged for exceeding the time bid. Second, if no maximum is set for B, then a bidder with a high B and a low-cost bid may be awarded the job and make an unreasonable amount of money from incentive payments. This study develops a quantified model of the price-time bidding contract. A construction cost-versus-time curve is developed from Florida Department of Transportation (DOT) data. The contractor’s price-versus-time curve is then combined with the road-user cost to determine the optimum lower limit to be set on B. Finally, several projects completed by the Florida DOT will be used to illustrate this model.

An evaluation of warranty contracting in the United States of America

2006 ◽  
Vol 33 (1) ◽  
pp. 1-9 ◽  
Author(s):  
Mehmet Emre Bayraktar ◽  
Qingbin Cui ◽  
Makarand Hastak ◽  
Issam Minkarah
Keyword(s):  
United States ◽  
United States Of America ◽  
The United States ◽  
Department Of Transportation ◽  
Construction Costs ◽  
Advantages And Disadvantages ◽  
Contract Administration ◽  
State Highway ◽  
Early Failures ◽  
State Highway Agencies

It is believed that warranty contracting would benefit state highway agencies by improving quality, saving money and time, and encouraging contractors' innovations. However, the challenges associated with warranties could be substantial, including higher costs, early failures, a reduction or even elimination of small contractors from the bidding process, and an increase in contract disputes and litigation. The actual impact of warranty provisions on state Department of Transportation (DOT) projects in the United States of America is still unclear because of limited industry experience. This paper provides a detailed discussion of warranty provisions and the benefits and problems associated with the subject matter. The advantages and disadvantages of warranty provisions are evaluated from the conflicting perspectives of state Departments of Transportation (DOTs), contractors, and surety companies. The future prospects of warranty provisions are established based on the findings of a recent study of warranty provisions and existing literature. Also, several options are proposed that have a strong potential to improve the application of warranties on DOT projects.Key words: warranties, highway construction, innovation, highway maintenance, contract administration, construction costs, construction inspection.

Fixed Instrumentation for Monitoring Scour at Bridges

1998 ◽  
Vol 1647 (1) ◽  
pp. 1-9 ◽  
Author(s):  
P. F. Lagasse ◽  
E. V. Richardson ◽  
J. D. Schall
Keyword(s):  
Low Cost ◽  
Technical Skills ◽  
Bridge Piers ◽  
Department Of Transportation ◽  
Monitoring Methods ◽  
State Highway ◽  
Scour Monitoring ◽  
Wide Range ◽  
Maintenance And Inspection ◽  
State Highway Agencies

Research was conducted to develop, test, and evaluate fixed instrumentation that would be both technically and economically feasible for use in measuring maximum scour depth at bridge piers and abutments. A variety of scour-measuring and scour-monitoring methods were tested in the laboratory and in the field, including sounding rods, driven-rod devices, sonic depth finders (fathometers), and buried devices. Two fixed-instrument systems, a low-cost fathometer, and a magnetic slidingcollar device using a driven-rod approach, showed significant promise during initial testing. The project concentrated on installing and testing these two instrument systems under a wide range of bridge substructure geometry, flow, and geomorphic conditions. Both instrument systems met all of the mandatory and many of the desirable criteria established for this research. Cooperative efforts with state highway agencies proved that both systems can be installed with equipment and technical skills normally available to district-level department of transportation maintenance and inspection personnel. The project also provided installation, operation, and fabrication manuals for the low-cost sonic instrument system and magnetic sliding-collar devices.

scholarly journals Road User Costs for Highway Construction Projects Involving a Lane Closure

2020 ◽  
Vol 12 (8) ◽  
pp. 3084
Author(s):  
Jaehyun Choi
Keyword(s):  
Construction Projects ◽  
Road User ◽  
State Agencies ◽  
User Cost ◽  
Unique Problem ◽  
User Costs ◽  
State Highway ◽  
Florida Department ◽  
Commercial Software Package ◽  
State Highway Agencies

While for years most American State Highway Agencies (SHAs) have performed Road User Cost (RUC) calculations, no uniformity from state to state has been established. There is scant research available that documents the testing and validation of existing RUC calculation methods for highway rehabilitation projects. Especially scarce are studies addressing the unique problem of accurately calculating RUC in the event of lane closures. This research addresses this problem by describing and comparing two methods of making such calculations: A manual method developed by the Texas Transportation Institute (TTI), and adopted by many other state agencies, such as the Florida Department of Transportation (FDOT), and a commercial software package.

scholarly journals Ontology-Based Knowledge Management System for Digital Highway Construction Inspection

2019 ◽  
Vol 2673 (1) ◽  
pp. 52-65 ◽  
Author(s):  
Xin Xu ◽  
Chenxi Yuan ◽  
Yuxi Zhang ◽  
Hubo Cai ◽  
Dulcy M. Abraham ◽  
...  
Keyword(s):  
Inspection System ◽  
Construction Process ◽  
Department Of Transportation ◽  
State Highway ◽  
Training Materials ◽  
Ontological Approach ◽  
Construction Inspection ◽  
State Highway Agencies ◽  
And Training

Inspection is critical to ensuring the quality of infrastructure construction. In recent years, state highway agencies (SHAs) have been facing the challenge of a shortage of experienced inspectors due to retirements, workforce downsizing, and resignations to take jobs in the private sector. There is a critical need to retain and manage the accumulated construction inspection knowledge (what, when, and how to inspect) and integrate this knowledge into the construction business process. This paper presents an ontological approach to managing inspection knowledge and the development of a risk-based digital inspection system integrated with the construction process. The developed system consists of five knowledge compartments: inspection activities prioritized based on risk; activity-centered pay items; inspection check items; detailed checks that include priority, frequency, object, attribute, and acceptance criteria; and training materials (optional). This risk-based system is designed to align with the construction process by connecting an activity to a pay item and that pay item to a check item, resulting in an automatically generated comprehensive inspection checklist for the activity. The optional training materials are designed to train inspectors in real time on an as-needed basis. Since risk is embedded in every knowledge compartment, this system not only automates and retains the inspection knowledge but also enables SHAs to allocate their limited resources to the most critical items. This system is currently being implemented by the Indiana Department of Transportation as a digital inspection protocol integrated in its e-construction process.

Using Artificial Intelligence to Estimate Nonlinear Resilient Modulus Parameters from Common Index Properties

2021 ◽  
pp. 036119812110237
Author(s):  
Laura Camarena
Keyword(s):  
Machine Learning ◽  
Material Properties ◽  
Resilient Modulus ◽  
Nonlinear Behavior ◽  
Machine Learning Techniques ◽  
Design Parameters ◽  
Nonlinear Parameters ◽  
State Highway ◽  
Learning Techniques ◽  
State Highway Agencies

The Mechanistic–Empirical Pavement Design Guide (MEPDG) considers a hierarchical approach to determine the input values necessary for most design parameters. Level 1 requires site-specific measurement of the material properties from laboratory testing, whereas other levels make use of equations developed from regression models to estimate the material properties. Resilient modulus is a mechanical property that characterizes the unbound and subgrade materials under loading that is essential for the mechanistic design of pavements. The MEPDG resilient modulus model makes use of a three-parameter constitutive model to characterize the nonlinear behavior of the geomaterials. As the resilient modulus tests are complex, expensive, and require lengthy preparation time, most state highway agencies are unlikely to implement them as routine daily applications. Therefore, it is imperative to make use of models to calculate these nonlinear parameters. Existing models to determine these parameters are frequently based on linear regression. With the development of machine learning techniques, it is feasible to develop simpler equations that can be used to estimate the nonlinear parameters more accurately. This study makes use of the Long-Term Pavement Performance database and machine learning techniques to improve the equations utilized to determine the nonlinear parameters crucial to estimate the resilient modulus of unbound base and subgrade materials.

Pay Factor Analysis for Highway Pavements through Percentage of Material within Specification Limits and Monte Carlo Simulation

2021 ◽  
pp. 036119812110255
Author(s):  
Yunpeng Zhao ◽  
Dimitrios Goulias
Keyword(s):  
Monte Carlo Simulation ◽  
Monte Carlo ◽  
Operating Characteristic ◽  
Production Quality ◽  
Specification Limits ◽  
State Highway ◽  
Long Run ◽  
Similar Materials ◽  
Pay Factor ◽  
State Highway Agencies

Many state highway agencies (SHAs) have adopted pay adjustment provisions in their acceptance plans for construction and materials. In these payment adjustment acceptance plans, the percentage of material within specification limits (PWL) has been selected as the quality measure to relate production quality to pay factors, and pay equations are used to determine a pay factor for a lot based on PWL. Various pay equations have been proposed by the highway community for adoption in SHAs’ specifications. However, the effectiveness of these pay equations has not been fully evaluated. Another issue concerning the pay adjustment acceptance plans is the risk associated with single and multiple pay factors. The purpose of this study was to evaluate the effects of different pay equations commonly used by SHAs and the risks associated with pay adjustment acceptance plans. This was achieved by developing operating characteristic curves associated with various pay factors and expected pay curves and Monte Carlo simulation for assessing the effects in the long run. The methodology suggested in this paper is transferable elsewhere where similar materials and specifications are used for the acceptance of pavements.

Integrating Visualization into Structured Public Involvement: Case Study of Highway Improvement in Central Kentucky

2002 ◽  
Vol 1817 (1) ◽  
pp. 50-57 ◽  
Author(s):  
Keiron Bailey ◽  
Joel Brumm ◽  
Ted Grossardt
Keyword(s):  
User Satisfaction ◽  
Public Involvement ◽  
Systems Approach ◽  
Three Dimensional ◽  
Factors Affecting ◽  
State Highway ◽  
Advanced Technologies ◽  
Design Options ◽  
State Highway Agencies

Public involvement in transportation infrastructure decision making is frequently mandated and is regarded as increasingly essential by a wide variety of stakeholders. The integration of advanced technologies, such as visualization, into this process is increasingly desired. However, public involvement processes often are regarded as problematic by many stakeholders and the state highway agencies charged with implementing them. Structured public involvement (SPI) is posited. SPI takes a systems approach toward the integration of advanced technologies into public involvement forums. Because the goal of public involvement is to increase user satisfaction with both the process and the outcomes, the characteristics of advanced technologies and their capacities for gathering useful feedback in public forums must be evaluated. Visualization is put forth as an enabling technology within an SPI framework. The properties, capacities, and transportation-related uses of three visualization modes are evaluated, and their operational features are discussed. A case study dealing with highway improvement in central Kentucky reveals that three-dimensional renderings are significantly preferred to twodimensional and virtual reality modes; the case study also shows that visualization should complement, not replace, other performance information. The role of electronic scoring as an integral component of this SPI protocol is emphasized, resulting in fast assessment and free expression of views. Factors affecting the efficiency of visualization are analyzed, and recommendations are presented for implementing SPI protocols that rely on visualization. These include investigating participants' previous experience with visualization, incorporating iterative public involvement in finalizing design options, and ensuring that the technologies are compatible with the chosen public involvement process.

Development and Implementation of a Pavement Marking Management System in Florida

2018 ◽  
Vol 2672 (12) ◽  
pp. 209-219
Author(s):  
Bouzid Choubane ◽  
Joshua Sevearance ◽  
Charles Holzschuher ◽  
James Fletcher ◽  
Chieh (Ross) Wang
Keyword(s):  
Management System ◽  
Handheld Devices ◽  
Department Of Transportation ◽  
Pavement Markings ◽  
Lighting Conditions ◽  
Florida Department ◽  
Roadway Safety ◽  
Application Techniques ◽  
Effective Use ◽  
Pavement Marking

The visibility of pavement markings is an important aspect of a safe transportation system as the markings convey vital roadway warnings and guidance information to the traveling public. Therefore, it is beneficial to maintain acceptable visibility levels of markings on pavements under all weather and lighting conditions. To ensure the intended in-service visibility level is adequately maintained, the reflectivity must be monitored and quantified accordingly. Historically, visibility or retroreflectivity of in-service pavement markings has been measured with handheld devices and visual inspections. However, visual surveys are considered subjective and the handheld measurements are tedious and potentially hazardous. Consequently, the Florida Department of Transportation (FDOT) has focused on the use of a non-contact technology capable of assessing pavement markings continuously at highway speeds with improved safety and efficiency. The use of mobile technology for measuring reflectivity has allowed FDOT to develop and, subsequently, implement a Pavement Marking Management System (PMMS) to improve the safety and nighttime visibility of its roadways. Implementation of such a system provides an efficient and less subjective methodology to identify conditions that are detrimental to roadway safety, and strategize mitigating solutions including the selection of appropriate materials and application techniques. The system will ultimately result in an effective use of state funds while ensuring the safety of the traveling public. This paper presents a description of the Florida Pavement Markings Management System and its subsequent implementation including FDOT’s effort to ensure the quality, consistency, repeatability, and accessibility of statewide pavement marking retroreflectivity data.

Data Mining Statewide Department of Transportation Volumetrically Designed Asphalt Mixture Records

2021 ◽  
pp. 036119812110613
Author(s):  
Ben C. Cox ◽  
Jonathan Easterling ◽  
W. Griffin Sullivan ◽  
Alex Middleton ◽  
Isaac L. Howard
Keyword(s):  
Asphalt Binder ◽  
Asphalt Mixture ◽  
Mechanical Tests ◽  
Unintended Consequences ◽  
Mix Design ◽  
Department Of Transportation ◽  
Database Analysis ◽  
Societal Pressure ◽  
Asphalt Content ◽  
Asphalt Paving

In recent years, the asphalt paving industry has been strained by numerous factors including increased asphalt binder costs, funding that has not kept up with material costs, increased societal pressure to recycle, and deteriorating pavement networks. Mix design should account for the market in which it is used, which is very different now than when today’s volumetric mix design practices were developed (many of the aforementioned factors were less present). Given this reality, a statewide database of all 1,452 approved mix designs in Mississippi from 2005 to 2018 was compiled and analyzed, and the objective of this paper is to present findings, trends, and unintended consequences of exclusive reliance on volumetrics. With volumetrics-only mix design, asphalt content is primarily controlled by voids in mineral aggregate (VMA), which is influenced by aggregate bulk specific gravity (Gsb). Minor Gsb deviations (i.e., within AASHTO d2 s limits), can significantly affect VMA, so much so that 99% of Mississippi’s mixes could be failing VMA while reported VMA passes. This allows mix manipulation and economization, with 0.8% asphalt content reductions possible while still meeting volumetric requirements. Recycled materials can exacerbate this issue, and common approaches to increase asphalt content (decreasing design gyration level or using finer gradations) are ineffective with fixed VMA requirements. Overall, the mix design database analysis agrees with numerous smaller studies but does so with an entire state’s actual practice. This presents a compelling case that volumetrics-only mix design has limitations, and supports ongoing efforts to reintegrate mechanical tests.

Sign in / Sign up

Export Citation Format

Share Document