This study investigated the current state of practice for crack sealing/filling. In addition, the INDOT crack sealing/filling practice was experimentally evaluated for the effectiveness of crack sealing/filling, the effectiveness of routing, the performance of the different types of crack sealants and fillers, the validity of sealant performance grade system, and the crack sealing/filling equipment performance. The key findings from an extensive literature review and nationwide/statewide survey performed in 2012 are the following: 1) 65% of the responses indicated that the routing is required for the crack sealing/filling application; 2) ASTM D 6690 Type II was the most widely used sealant type and only Missouri and Indiana included emulsions in their specifications as crack sealing/filling materials; and 3) crack sealing/filling equipment availability and their maintenance were the biggest concerns.Based on the two-year experimental investigation, the crack sealing/filling was determined to be effective in preventing the occurrence of pavement surface crack distress. The crack sealing/filling was concluded to be effective in maintaining crack integrity and resisting sealant and filler deformations due to the seasonal crack movement. The routing was not determined to be effective in terms of the pavement performances. However, Adhesive/Cohesive/Spalling (ACS) failure results showed that the routed sections significantly outperformed the non-routed sections. In addition, the test results indicated that the ASTM 6690 Type II crack sealants performed relatively well in terms of pavement and crack performance. The correlation between the sealant performance grades and the pavement and crack performances with different types of sealants and fillers were poor and insignificant.The mixed results regarding the effectiveness of the routing were obtained from the literature review and the field evaluation. As a result, it was recommended from the SAC meeting that routing in the 2090 Activity be limited to a single transverse crack (reflective cracks) on asphalt concrete over concrete pavements. INDOT currently uses the ASTM Type II crack sealants, which showed an overall good pavement and crack performances in the evaluation. Therefore, the current INDOT crack sealant material selection process (ASTM Type II) is concluded to be adequate.The experimental results showed that the cracks on wet pavement treated with HAL had significantly higher bonding between the materials and the asphalt pavement surface than the cracks treated with the conventional air compressor. Therefore, the incorporation of a hot air lance in the wet condition is recommended to extend the operable time and seasonal availability for crack filling and sealing construction (2070 and 2090 Activities).
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