Enhanced Treatment Selection for Reflective Joint Cracking in Composite Pavements

This research developed a decision-making process that can be used by INDOT to enhance identification of the condition of the underlying concrete joints or cracks by looking at the surface distresses of the asphalt overlay in composite pavements. In order to achieve the research objective, several tasks were performed during the research including literature reviews, data collection, and data analysis. In conjunction with the developed decision-making process, this study also developed a databased to organize the collected data and a computer application to not only increase the accessibility of INDOT field engineers to the sample data but also to improve the analysis process by providing better visualization tools. The data collection was performed based on four steps of field evaluation procedure (visual inspection of asphalt overlay, FWD testing, Coring, and visual inspection of exposed concrete). The collected data was analyzed to show distribution of joint and mid-panel cracks, and correlation between asphalt crack severity and concrete crack severity. Four input factors from the analyzed data (visual inspection of asphalt overlay, D1, LTE, and Resilient Modulus) were selected to develop the decision-making tool. A handbook is also provided to help INDOT field engineers’ decision-making during their field activities. The handbook contains important information of pavements, photographs of cracks, and the exposed concrete condition of sample data points for the benefit of field engineers. Recommendations and limitations are also discussed in this report

Benefits and Assessment of Annual Budget Requirements for Pavement Preservation

This research identifies methods and best practices that can be used by the Indiana Department of Transportation (INDOT) in performing various strategies for pavement preservation. It also identifies various methods of calculating benefits of pavement preservation and a methodology for allocation of funds for pavement preservation, which are the two main objectives of this research. In order to achieve these objectives, several tasks were performed: literature review, data collection through Surveys and telephone interviews, data analysis and recommendations. For the data collection process, all the DOTs across the US and three Canadian provinces were sent a Survey. A total of 26 responses were received, and by analyzing them thoroughly, seven State DOTs were identified as candidates for telephone interviews. In order to quantify the benefits of pavement preservation, a method called Annualized Costs was identified and recommended to INDOT. Furthermore, a methodology was developed for budget allocation. This methodology was developed to create more consistent demands for resources (i.e., budget) by using a resource leveling algorithm. This algorithm overcame the discrepancies in budget requirements, presenting more balanced budgetary needs over the entire life cycle of the projects. With this model, INDOT will know in advance how much budget will be needed or should be allocated to achieve optimum results. All these recommendations were made on the basis of collected data and literature review performed by researchers during the course of this project

What construction topics do they discuss in social media? : a case study of Weibo in China

As a traditional industry such as the construction, it is hard to collect data for management and improvement. Traditional ways such as questionnaire survey, interviews, or focus meetings to collect data are both time- and cost-consuming. Recently, with the rapid development of social media services, data can be collected and extracted for topic analysis to provide officials and managers with fresh perspectives on participants in the construction management. In this paper, a topic analysis systematic framework is proposed. This system collected user messages from social media sites, establishes and compares different clusters’ topics and keywords in their messages. This paper generated valuable information and knowledge in the construction domain. As an initial trial, this study selected social media of Weibo because of its wide usage in China. Four clusters which include construction workers, construction companies, construction unions, and construction media were analyzed. For each user, the crawler is used to collect the Weibo messages from his/her web page. On average, there are 135 messages collected for each user. This research then analyzed these data in the following aspects to dig out information behind data: keywords, hashtags, and topic modeling. Detailed findings, benefits, and barriers to incorporating social media data analytics in the construction industry, along with future research, were discussed. This paper benefits the academia by testing an alternative way of studying the construction population, which further will help decision makers better understand the real situations of the construction industry

Surface and bulk structure investigation of fully delithiated bare and AIPO(4)-coated LixCoO2 (x=0) cathode materials annealed between 200 and 400 degrees C

The surface and bulk structure of the fully delithiated bare and AlPO4-coated LixCoO2 cathode materials (x = 0) between 200 and 400 ??C were investigated using high resolution XRD, XAS (X-ray absorption spectroscopy), TEM, and solid-state NMR. Bare and coated CoO2 cathodes showed different phase transformation between 200 and 400 ??C. The bare samples exhibited only the O1-CoO2 phase in the fully delithiated state, but the CoO2 phase was converted to the Co3O4 phase at higher temperatures. On the other hand, the AlPO4-coated LixCoO2 at x = 0 showed a mixture of phases including the major O1-type CoO2 and minor Co3O4 spinel phases in the fully delithiated state. When annealing temperatures increased from 200 to 400 ??C, the bare samples showed a slow phase transition to Co3O4 and were completely transformed into the thermally stable Co3O4 spinel phase at 400 ??C. The coated samples, however, were completely transformed into the spinel phase alone at 200 ??C. We believe that the AlPO4 coating layer accelerated the phase transition to the spinel phase at lower temperatures. TEM and XAS results showed that structural damages were mainly confined to the cathode particle surface, and this phenomenon was only observed in the bare samples.close3