Short term performance evaluation of thin maintenance surfaces on US 69 in Iowa

Abstract

Thin maintenance surfaces are an important part of a preventive maintenance program for flexible pavement in Iowa. With the increase of construction cost each year, emphasis has shifted to the pavement preservation technology to protect the pavement structure, slow the rate of pavement deterioration, and correct pavement surface deficiencies. Delays in maintenance increase the quantity and severity of pavement defects and result in higher costs during pavement life. The purpose of this study is to investigate the feasibility of using the surface treatments as preventive maintenance tool for restoring pavement condition. This involves the implementation of test sections on a local highway, US 69 in Iowa to explore the potential capabilities of these surface treatments in correcting different severity of surface distresses and thus improving the pavement condition. It also examines the performance of the different combinations between the aggregates and the asphalt binders used for several treatments. As the performance information is collected, this information is used to assist the researchers in developing guidelines for the use of thin maintenance surfaces to be included in the overall Iowa DOT pavement management program. Comparison is also made between the US 69 test sections and both US 30 and US 151 test sections previously constructed in 1997 in Iowa in goals to improve and refine the existing guidelines. In conclusion, thin maintenance surfaces can be cost effective if the following recommendations are followed: 1) Equipment calibration is desired to ensure that the target material quantities are applied during construction, 2) the sampling of the test sections for performance evaluation to ensure that the number of sample units taken is representative of the entire section, 3) the design of the seal coat application rates, and 4) the type of the aggregate and the binder used for the seal coat mix design. However, the short-term data availability from this project prevents a thorough analysis on the impact of the surface treatments to the pavement surface. Therefore, continuous performance assessment is desired to validate and verify the results of this study.