One of the most effective methods of asphalt pavement preservation is crack sealing. Sealing cracks in asphalt pavements helps reduce moisture anddebris infiltration into the pavement structure resulting in increased life expectancy of the pavement. However, there are many crack sealants andseveral methods of installation available. To help answer this question an experiment was designed to evaluate performance of three crack sealants placed in three environments using three distinct installation procedures and two methods of crack filling resulting in three factorials with eighteen treatments per location. Each supplier of crack sealant was instructedto bring the materials, equipment and personnel necessary to successfullyinstall each of the products in six cracks per each of the treatment combinations for a total of 108 cracks per location. The objective of the experiment was to determine short and long term performance characteristics of each combination of material, method and location. Two methods were usedto measure performance. These included evaluating the amount and severity of cracking as a function of the original filled crack length, and the Sealant Condition Number. Results indicate that performance suffers when the heat lance is used in preparation of crack filling at the temperatures utilized and that performance improves when the sealant is squeegeed over the crack after air blowing or routing. Routing the crack prior to sealingappears to improve performance. The surprisingly poor five month performance of some of the crack sealant methods indicates that some pavements may not be sealed as well as some believe.
Abstract