This study evaluates the performance of eight hot mix asphalt (HMA) rehabilitation strategies utilized by the Colorado Department of Transportation (CDOT). The rehabilitation strategies are: 2 to 4-inch overlay without pretreatment; cold planing and overlay; stone matrix asphalt overlay; full-depth reclamation and overlay; heater scarification and overlay; heater remix and overlay; heater repaving and overlay; and cold-in-place recycling and overlay. Performance was evaluated with respect to six independent variables: (1) Performance Grade (PG) binder temperature range, (2) traffic volume, (3) highway classification, (4) maximum aggregate size, (5) CDOT region, and (6) climate. Data analyzed in the study were obtained from the CDOT Pavement Management System Program. Results of this analysis indicate that the cold planing and overlay strategy outperforms the other rehabilitation methods with 2 to 4-inch overlays performing second best. The heater scarification and overlay strategy performed poorest of the eight strategies. The average time required for these pavements to reach the pre-rehabilitation condition was from six to fourteen years based on a linear regression model. However, this model may overestimate rehabilitation life span since it is likely that a linear relationship is not valid for the entire rehabilitation strategy life cycle. Pavements were rehabilitated before reaching the zero service life threshold except when fatigue cracking was present. In the case of fatigue cracking, four rehabilitation strategies studied exceeded the zero service life threshold. This indicates that rehabilitation would have been warranted earlier in the life of these pavements. As a result, the expected life of the rehabilitation strategies utilized on these pavements may be shorter than could be expected had rehabilitation been done before distress reached this high level. This may explain why the heater scarification and overlay strategy performed poorer than other techniques since fatigue distress prior to rehabilitation on these projects exceeded the zero remaining service life threshold by nearly 20%. Continued transfer of pavement performance data from the CDOT Pavement Management System Program database is recommended to strengthen the validity of the data analysis.
[1]
Susan L. Tighe,et al.
Pavement Performance Evaluation of Three Canadian Low-Volume Test Roads
,
2007
.
[2]
Dennis A Morian,et al.
Techniques for Selecting Pavement Rehabilitation Strategies: Pennsylvania Case Studies
,
1997
.
[3]
Peter E. Sebaaly,et al.
Development of Performance Models Based on Department of Transportation Pavement Management System Data
,
1999
.
[4]
Samuel Labi,et al.
Measures of Short-Term Effectiveness of Highway Pavement Maintenance
,
2003
.
[5]
Tom Scullion,et al.
Lessons Learned on Jointed Concrete Pavement Rehabilitation Strategies in Texas
,
2006
.