Field Performance and Cost Effectiveness of Crack Sealing in Flexible and Composite Pavements is a well-researched engineering Thesis/Dissertation topic, it is to be used as a guide or framework for your Academic Research.
Surface cracking is one of the major surfaces distresses in asphalt concrete (AC) pavement, allowing water infiltration through the cracks, causing stripping in asphalt pavement layers, and weakening and deteriorating the base and/or subgrade. Its treatment, therefore, is one of the major activities in pavement preservation for many state DOTs.
Among the various treatment methods currently available to preserve AC pavement with existing surface cracking are various forms of crack sealing. Crack sealing is not a common practice to Louisiana highways since the benefit of such treatment appears to be affected by the elevation of the groundwater table. Studies completed in the 1960s for Louisiana showed that sealing roads in an area with a high groundwater table accelerated AC stripping.
The explanation was that crack sealing in such a situation prevented moisture from escaping upwards through the cracks of the AC pavements. The objective of this dissertation was twofold. First, this study quantified the benefits of using crack sealing with respect to its ability to provide immediate benefits and long-term benefits.
Based on this evaluation, the research team developed regression models that predict crack sealing benefits; in terms of extension in pavement service life, based on the project conditions. Second, this dissertation evaluated the potential moisture damage in pavements treated with crack sealing.
Based on this evaluation, the research team developed a regression model that determines whether crack sealing should be used to avoid moisture damage in a cracked pavement at a given site based on the groundwater table depth and air relative-humidity.
Furthermore, this project assessed the optimal application timing of crack sealing through evaluating its cost-effectiveness using common economic measures. To facilitate the implementation of the results, a user-friendly tool in the form of a spreadsheet was designed that could be used by state agencies during planning for crack sealing.
Historically, crack sealing has not been favored by the Louisiana Department of Transportation and Development (LaDOTD) but this treatment has gained interest in recent years. However, studies that provide a clear quantitative justification that cracks sealing is cost-effective for hot and humid climates are limited in scope, and few in number (Hand et al. 2000).
Therefore, the use of crack sealing in Louisiana has been sporadic and based on the assumption that the benefits of crack sealing would outweigh the costs. A number of practitioners in Louisiana also believe that the performance of Crack sealing would be affected by the shallow groundwater table and rainfall infiltration.
Earlier studies showed that sealing roads in an area with a high groundwater table may accelerate AC stripping. The explanation was that sealing in such a situation prevented moisture from escaping upwards through the surface cracks of the pavement (McKesson 1949).
Yet, current crack sealing application practices are based on visual inspection without considering groundwater table level, climatic conditions, prior pavement conditions, or any other significant factors.