Pavement Preservation Journal - Fall 2016 - 39

New Mechanistic Tool Assesses Joint Sealant Effectiveness A mechanistic tool for analysis of specific combinations of traffic, climate, base materials and sealant condition on subbase erosion and pavement performance is the first tool of its kind that allows assessment of the sealant effectiveness on pavement performance. The Seal/No Seal (SNS) Group has released the results of the study by Dr. Dan Zollinger at the Texas A&M Transportation Institute (TTI), called Qualification of Joint Sealant Effectiveness Regarding Jointed Concrete Pavement Performance. This study did not attempt to research sealant effectiveness through traditional approaches such as characterizing sealant performance in terms of joint seal properties. Instead, TTI took a more rigorous approach to evaluate performance in terms of the amount of infiltration through the joint, and the consequential impacts on subbase erosion and pavement distress. Another aspect of the study evaluated the use of ground penetrating radar (GPR) to detect the existence of moisture under the slabs. With the use of GPR, it now appears feasible to detect the existence of moisture under the slabs in the vicinity of the joint from a water infiltration standpoint, and more importantly, to assess when a sealant is no longer effective. The Seal/No Seal Group was formed to respond to the age-old industry question about the value of sealing concrete pavement joints. Its mission is to develop a committed membership that takes responsibility for determining the long-term effectiveness of sealants in concrete pavements. resuLts oF reseArch One of the most important effects of joint sealant effectiveness on concrete pavement performance is the potential for subbase erosion. The Excel spreadsheet-based application developed by Zollinger in support of this research demonstrates several aspects of sealant effectiveness on pavement performance. The spreadsheet uses a mechanistic-empirical approach to consider the three main elements of subbase erosion: the rate of erosion of the base/subbase, existence of moisture under the slab (as reflected by the number of wet days), and traffic. The model was calibrated with lab and field data and is useful for design and maintenance purposes. The experimental results showed that if joint seals are properly installed, they can be very effective in preventing moisture infiltration. Unsealed joints have significantly higher inflow rates compared to joints with damaged sealants. The water infiltration rates for dirty joints, such as sealants installed in an unclean reservoir, or dirt-filled unsealed joints, were as high as those for clean joints with 50 percent debonding. Further, Zollinger found the management of a sustainable concrete pavement system requires greater emphasis on performance monitoring, rather than performance repair; it's a concept not widely practiced, and which challenges traditional repair and rehabilitation philosophies. Why seAL joints? The primary purpose for sealing joints in rigid pavement is to prevent or reduce the amount of water and incompressibles infiltrating into Water-related damages: potholes, corner breaking and wide cracks Joint Infiltration testing was conducted on in-service pavements the pavement structure. It is well accepted that both issues contribute to a variety of distress types eventually deteriorating the pavement structure, resulting in decreased service life. An inevitable consequence of water infiltration through joints in concrete pavement is the erosion at the slab/ subbase interface. Subbase erosion directly contributes to the process of joint faulting, which can involve several Fall 2016 pavement preservation journal 39

Table of Contents for the Digital Edition of Pavement Preservation Journal - Fall 2016

President’s Message
Still Time to Visit NPPC 2016
NCAT: Quantifying Southern Treatments, Placing Northern Treatments
LTPP Tackles Pavement Preservation
D.C. Update: Capitol Hill Etiquette for Visits
FP2 @ Eurasphalt & Eurobitume 2016
Los Angeles County Abandons 'Worst First' Pavement Program
High-Volume U.S. 3 Gets R26 Showcase Preservation
New Mechanistic Tool Assesses Joint Sealant Effectiveness
Index of Advertisers
Pavement Preservation Journal - Fall 2016 - Cover1
Pavement Preservation Journal - Fall 2016 - IBD_L
Pavement Preservation Journal - Fall 2016 - IBD
Pavement Preservation Journal - Fall 2016 - cover2
Pavement Preservation Journal - Fall 2016 - 3
Pavement Preservation Journal - Fall 2016 - 4
Pavement Preservation Journal - Fall 2016 - 5
Pavement Preservation Journal - Fall 2016 - 6
Pavement Preservation Journal - Fall 2016 - 7
Pavement Preservation Journal - Fall 2016 - 8
Pavement Preservation Journal - Fall 2016 - President’s Message
Pavement Preservation Journal - Fall 2016 - 10
Pavement Preservation Journal - Fall 2016 - Still Time to Visit NPPC 2016
Pavement Preservation Journal - Fall 2016 - 12
Pavement Preservation Journal - Fall 2016 - 13
Pavement Preservation Journal - Fall 2016 - 14
Pavement Preservation Journal - Fall 2016 - 15
Pavement Preservation Journal - Fall 2016 - 16
Pavement Preservation Journal - Fall 2016 - NCAT: Quantifying Southern Treatments, Placing Northern Treatments
Pavement Preservation Journal - Fall 2016 - 18
Pavement Preservation Journal - Fall 2016 - 19
Pavement Preservation Journal - Fall 2016 - LTPP Tackles Pavement Preservation
Pavement Preservation Journal - Fall 2016 - 21
Pavement Preservation Journal - Fall 2016 - 22
Pavement Preservation Journal - Fall 2016 - 23
Pavement Preservation Journal - Fall 2016 - 24
Pavement Preservation Journal - Fall 2016 - D.C. Update: Capitol Hill Etiquette for Visits
Pavement Preservation Journal - Fall 2016 - 26
Pavement Preservation Journal - Fall 2016 - FP2 @ Eurasphalt & Eurobitume 2016
Pavement Preservation Journal - Fall 2016 - 28
Pavement Preservation Journal - Fall 2016 - Los Angeles County Abandons 'Worst First' Pavement Program
Pavement Preservation Journal - Fall 2016 - 30
Pavement Preservation Journal - Fall 2016 - 31
Pavement Preservation Journal - Fall 2016 - 32
Pavement Preservation Journal - Fall 2016 - 33
Pavement Preservation Journal - Fall 2016 - High-Volume U.S. 3 Gets R26 Showcase Preservation
Pavement Preservation Journal - Fall 2016 - 35
Pavement Preservation Journal - Fall 2016 - 36
Pavement Preservation Journal - Fall 2016 - 37
Pavement Preservation Journal - Fall 2016 - 38
Pavement Preservation Journal - Fall 2016 - New Mechanistic Tool Assesses Joint Sealant Effectiveness
Pavement Preservation Journal - Fall 2016 - 40
Pavement Preservation Journal - Fall 2016 - 41
Pavement Preservation Journal - Fall 2016 - Index of Advertisers
Pavement Preservation Journal - Fall 2016 - cover3
Pavement Preservation Journal - Fall 2016 - cover4
Pavement Preservation Journal - Fall 2016 - outsert1
Pavement Preservation Journal - Fall 2016 - outsert2
Pavement Preservation Journal - Fall 2016 - outsert3
Pavement Preservation Journal - Fall 2016 - outsert4
https://www.nxtbook.com/naylor/FPPQ/FPPQ0318
https://www.nxtbook.com/naylor/FPPQ/FPPQ0218
https://www.nxtbook.com/naylor/FPPQ/FPPQ0118
https://www.nxtbook.com/naylor/FPPQ/FPPQ0417
https://www.nxtbook.com/naylor/FPPQ/FPPQ0317
https://www.nxtbook.com/naylor/FPPQ/FPPQ0217
https://www.nxtbook.com/naylor/FPPQ/FPPQ0117
https://www.nxtbook.com/naylor/FPPQ/FPPQ0416
https://www.nxtbook.com/naylor/FPPQ/FPPQ0316
https://www.nxtbook.com/naylor/FPPQ/FPPQ0216
https://www.nxtbook.com/naylor/FPPQ/FPPQ0116
https://www.nxtbook.com/naylor/FPPQ/FPPQ0415
https://www.nxtbook.com/naylor/FPPQ/FPPQ0315
https://www.nxtbook.com/naylor/FPPQ/FPPQ0215
https://www.nxtbook.com/naylor/FPPQ/FPPQ0115
https://www.nxtbookmedia.com