An impact study on a long-span continuous highway steel girder bridge is described. Crawl and full-speed test data were analyzed to examine the influence of bridge approach, surface condition, and truck velocity on impact factors for fatigue-prone details in both main and secondary bridge members. The measured impact factors for fatigue stress categories A, B, E, and E’ details were compared with values obtained using the American Association of State Highway and Transportation Officials (AASHTO) Standard Specifications formula. For fatigue-prone details, the test results showed that surface roughness, truck velocity, and bridge approach affect the impact factor. Measured impact factors varied with the location of the detail. Also, the study showed that the AASHTO design impact factors were unconservative for details located in the bridge approach or end span.

This paper examines the public and private sectors' perception of key factors that influence the implementation of Public-Private Partnership (PPP) in the infrastructure development of Afghanistan -one of the poorest countries in the world where decades of conflict has destroyed much of its infrastructure. The data for this study was drawn through a comprehensive research approach that included a literature review; interviews/discussions with professional experts, experienced practitioners, and decision-makers in Afghanistan; as well as a qualitative survey questionnaire. This study identified thirty-seven critical success factors (CSF) that impact the success of PPP projects in Afghanistan. The most important CSFs were determined to be (1) the need for experienced technical and financial experts in the PPP unit of Afghanistan, (2) promotion of various financing mechanisms by PPP law, (3) establishment of clear financial objectives for PPP projects, and (4) up-front cost/benefit analysis. This study further identified CSFs that significantly hindered the success of PPPs in Afghanistan. These included political and legislative instability, absence of risk management experts and long project approval process, and the on-going political and security uncertainty. The result of an independent t-test showed that, with the exception of three factors, there was no significant difference between the perception of the private and public sectors concerning the importance of the identified CSFs. The factors identified in this study should be given utmost consideration by all the stakeholders to ensure the successful implementation of PPPs in the infrastructure development of Afghanistan. The findings of this study could also be used by researchers in Afghanistan and other developing countries to develop a theoretical body of PPP knowledge for future research.

Two important parameters in fatigue life evaluations of existing steel highway bridges are the number of stress cycles experienced and the effective stress range. The inaccuracies in predicting remaining fatigue life can be attributed to either one of these two parameters. However, the AASHTO guide specification has no provisions for the cycle-counting methods to be used to determine these two parameters. A sensitivity analysis that addresses the effects of cycle-counting methods on the effective stress range and the number of cycles for various fatigue-prone details in both main and secondary bridge members is described. A comparison of five cycle-counting methods (level-crossing counting, peak counting, simple-range counting, mean-crossing-peak counting, and rain-flow counting) by using a simple variable-amplitude strain-time history showed that both the stress range and the number of cycles are sensitive to cycle-counting methods. Two of the most commonly used cycle-counting techniques for highway bridge variable-amplitude loading are the mean-crossing-peak and the rainflow cycle-counting methods. A comparison of the two methods by using field data taken under normal traffic showed that the rainflow cycle-counting method is more conservative than the mean-crossing-peak method. The relationship between the mean-crossing-peak and the rainflow cycle-counting methods was determined in the form of a correlation coefficient and a linear regression line. There is a nearly perfect positive correlation between the two methods. Therefore, values obtained for the effective stress range and the number of cycles by the mean-crossing-peak method can be converted to values for the rainflow method.

Approximately 95 million metric tons of asphalt is recycled each year in the US; making it one of the most recycled materials. The technology for use of close to 100% recycled asphalt (RAP) is available. This study examines how owners of projects view the idea of using 100% RAP. The objectives of this study were to obtain city, town, county, and state government officials' opinions on the use of 100% RAP and to find out how respondents felt about the use of RAP in their current asphalt roads. A survey was sent to 250 industry officials from all over the country. Statistical tests were conducted to see if the results were indicative of the population. Results show that there is some hesitation in the use of 100% recycled asphalt due to the unknown properties of the asphalt, past performance issues dealing with asphalt containing less than 100% RAP, and the unknown life expectancy of the 100% recycled asphalt. Also it was determined that 100% recycled asphalt would have to be less expensive than current asphalt on the market for it to be attractive.

Instructors develop courses to promote student learning and a multitude of strategies to measure if learning occurs through exams, projects, and other assignments. However, the measurements may also be an indication of how well the students cheat. In the classroom, proctors and multiple versions of an exam help to deter cheating, and comparing right and wrong answers among students helps to detect it. Video proctors for Online exams prove effective at preventing cheating, but they pose privacy and other issues. Comparing right and wrong answers between students remains a useful tool to detect online cheating. We propose analyzing learning management system (LMS) data to support and possibly replace other detection methods. LMS data have the potential to reveal cooperating students through a statistical analysis of student answer times. The proposed methodology is accessible to instructors without involving administrators in data collection.