Surface Layer Bond Stresses and Strength
https://apps.dot.state.nc.us/Projects/Research/ProjectInfo.aspx?ID=3081
Record Type: DOT

The importance of proper bonding at the asphalt concrete (AC) layer interface cannot be overemphasized when discussing the performance of AC pavements. Several pavements in North Carolina have experienced premature cracking, and forensic investigations have revealed that the debonding of the top surface layer is the primary reason for these failures. A strong bond between the layers is critical to dissipate shear stresses into the entire pavement structure. In contrast, insufficient bonding may cause slippage and activate distress mechanisms that will rapidly lead to total failure of the pavement. The primary objective of the proposed research is to develop a comprehensive guideline to minimize the debonding distress in asphalt pavements. This guideline will include an analysis framework to determine the critical stresses in layered asphalt pavement, a test method that can be used preferably in the field to measure the interface bond strength between the asphalt layers, recommendations for tack coat materials and rates for various existing pavement surface conditions, and assessment of the effects of various pavement and environmental factors on the interface bond strength. A particular focus of the study will be the distribution and dissipation of shear stresses under traffic loading and ways that such stress affects the interlayer bonding. It is proposed that some test methodologies developed in the recently completed NCHRP Project 9-40 will be evaluated in this study for possible implementation. The research products from this study will be used to provide pavement design elements and construction procedures or guidelines to reduce the likelihood of debonding of the top surface layer in an asphalt pavement. The results of this study will enable pavement designers to select appropriate tack materials and rates for specific applications to reduce the likelihood of debonding of the surface layer. The design elements and revised construction procedures developed from the proposed study would reduce premature distresses, thereby leading to savings in pavement maintenance and rehabilitation costs.
Start date: 2012/8/16
End date: 2014/8/15
Status: Active
Contract/Grant Number: 2013-04
Total Dollars: $312,000
Source Organization: North Carolina Department of Transportation
Date Added: 06/12/2012
Index Terms: Asphalt concrete, Bonding, Cracking, Surface course (Pavements), Pavement layers, Failure, Slipperiness, North Carolina,

North Carolina Department of Transportation
www.ncdot.org/doh/preconstruct/tpb/research/
Research and Development
1549 Mail Service Center
Raleigh, NC 27699-1549
USA
Phone: (919) 508-1790
Fax: (919) 715-0137

Kadibhai, Mustansir A.
Phone: (919) 508-1819
Fax: (919) 715-0137
Email: mkadibhai@ncdot.gov

North Carolina State University, Raleigh
Department of Civil Engineering, Campus Box 7908
Raleigh, NC 27695-7908
USA

Kim, Y. Richard
Phone: (919) 515-7758
Fax: (919) 515-7908
Email: kim@eos.ncsu.edu

Tayebali, Akhtarhusein A.
Phone: (919) 515-7611
Fax: (919) 515-7908
Email: tayebali@eos.ncsu.edu

Guddati, Murthi
Phone: (919) 515-7699
Fax: (919) 515-7908
Email: murthy.guddati@ncsu.edu