2013 Session: 698

• Laboratory Evaluation and Field Investigation of Asphalt Pavement Crack Seal Band
  Abstract: Crack sealing and filling is one of the most successful treatments for asphalt pavement preventive maintenance. The traditional crack seal materials, such as bituminous sealant or silicone sealant, unfortunately, cannot meet the requirements for open to traffic rapidly because of high volume traffic in China. Thus, a new seal material called seal band began to be applied to crack filling recently. Three test methods include penetration cone, softening point and modified bond were proposed to evaluate seal band. Then, installation configuration and field performance of seal band were investigated. The field studies indicate the treatment does not require melters, pumps or routing cracks for installation, applying seal band is as simple as blowing the pavement making sure the surface is clean and dry, unrolling and applying it to the surface. Failure investigation shows seal band can fail in three modes, included cohesion failure, adhesion failure and pullout. The investigation also discovers seal band shows better field performance than silicone sealant and hot-applied sealant. Properly installed, seal band prevents water intrusion and the deterioration it causes to the pavement.
  Authors: Li, Feng; Shi, Xiaopei; Zeng, Wei; Xu, Jian
  Authors: Li, Feng; Shi, Xiaopei; Zeng, Wei; Xu, Jian
  Year: 2013
  Document Type: Paper
  Subject: Maintenance and Preservation; Pavements
  Session: 698
  Paper Number: 13-0396
• A Preliminary Analysis on Determination of Optimum Crack Sealing Time for Asphalt Pavement
  Abstract: Crack is one of the major causes of failure in asphalt pavements, and it also accelerates the severity of other distresses. Crack sealing is one of the main methods of preventive maintenance. However, until now, there has no standard procedure based on rigorous scientific approach to determine the best sealing time of the cracks. Therefore, this study aimed to establish a preliminary crack opening model for northeast region of China. Generally, it is found that the absolute change value for crack width in one year is much higher than that in one day. Therefore the following preliminary crack opening model was built based on the year round observation data for unsealed asphalt pavement. The 20¡Á20 mm square reservoirs for crack sealing was selected to discuss the effect of sealing time on the crack sealing performance. The approximate analysis has shown that the unreasonable sealing time will induce the premature failure for sealant and sealant-crack system. Especially, at low temperature, the sealant needs to have a good ductility to prevent the fracture itself. Finally, a polynomial function was proposed to describe the crack opening distance. The model was then used to preliminary determine the appropriated crack sealing timing of the year. It is recommended that select the average temperature between the two inflexions in polynomial function as the sealing temperature, and the corresponding time as the sealing time. It is also noticed that this time varies for different regions.
  Authors: Yi, Junyan; Feng, Decheng; Yang, Shih-Hsien; Yu, Fei
  Authors: Yi, Junyan; Feng, Decheng; Yang, Shih-Hsien; Yu, Fei
  Year: 2013
  Document Type: Paper
  Subject: Maintenance and Preservation; Pavements
  Session: 698
  Paper Number: 13-1336
• Short-Term Kettle and Field Aging Investigation of Hot-Poured Crack Sealants
  Abstract: Hot-poured sealant treatments for cracks in flexible pavements are the most cost effective and commonly used pavement maintenance technique. The performance and longevity of such treatments after installation is heavily dependent on adhesive and cohesive properties of the sealing materials. Crack sealants exhibit significant potential for degradation due to aging that occurs due to heating during installation and due to weathering during their service life. Understanding the effects of aging on the rheological and mechanical properties of sealants is essential for prediction of their field performance. This paper investigates the use of performance-based tests to evaluate the short-term installation and long-term field aging effects. Performance based tests were developed for a sealant grading system similar to Superpave grading system for asphalt binders. Short-term aging was evaluated using samples collected from the kettles at regular intervals. Field aging was evaluated using samples obtained from the field after one year. Eight types of sealants were sampled from a test section where they were exposed to direct weathering effects including solar radiation, temperature variations, and moisture. Field samples include sealant extracted from routed and sealed cracks. The samples were sliced into two fractions in order to investigate differential aging of the sealant. The top 5 mm of sealant is designated as “crust”, while the remaining 15 mm are designated as “bottom”. All samples were subjected to a testing protocol including viscosity, flexural creep, and adhesion tests. Results indicate strong aging gradation from top to bottom in the samples collected from the routs 6-9 months after installation. An equation was proposed to predict average aging properties and estimate degree of field aging. This equation can be used to develop predictive performance models for sealants considering the intensity and gradation of aging on fundamental properties such as stiffness and viscosity.
  Authors: Ozer, Hasan; Al-Qadi, Imad L.; Castro, Guillermo Elizalde; Yousefi, Seyed Saleh
  Authors: Ozer, Hasan; Al-Qadi, Imad L.; Castro, Guillermo Elizalde; Yousefi, Seyed Saleh
  Year: 2013
  Document Type: Paper
  Subject: Maintenance and Preservation; Pavements
  Session: 698
  Paper Number: 13-4485
• Laboratory Evaluation and Field Investigation of Asphalt Pavement Crack Seal Band
  Authors: Li, Feng
  Authors: Li, Feng
  Year: 2013
  Document Type: Presentation
  Subject: Maintenance and Preservation; Pavements
  Session: 698
  Paper Number: 13-0396
• A Preliminary Analysis on Determination of Optimum Crack Sealing Time for Asphalt Pavement
  Authors: Yi, Junyan
  Authors: Yi, Junyan
  Year: 2013
  Document Type: Presentation
  Subject: Maintenance and Preservation; Pavements
  Session: 698
  Paper Number: 13-1336
• Short-Term Kettle and Field Aging Investigation of Hot-Poured Crack Sealants
  Authors: Al-Qadi, Imad
  Authors: Al-Qadi, Imad
  Year: 2013
  Document Type: Presentation
  Subject: Maintenance and Preservation; Pavements
  Session: 698
  Paper Number: 13-4485
• Short-Term Kettle and Field Aging Investigation of Hot-Poured Crack Sealants
  Authors: Ozer, Hasan
  Authors: Ozer, Hasan
  Year: 2013
  Document Type: Presentation
  Subject: Maintenance and Preservation; Pavements
  Session: 698
  Paper Number: 13-4485