Pavement Preservation Journal - Fall 2016 - 41

evaluate the potential for using GPR to detect when the sealant was allowing water infiltration into the joint. A handheld portable GPR unit was used for this testing. Subbase samples were also retrieved through core holes in the pavement to enable laboratory erosion testing using a Hamburg Wheel Rutting device. Falling weight deflectometer (FWD) testing important part of field evaluations factors. Faulting as a major distress type in jointed concrete pavements is a key feature in designing pavements. The effects of faulting have implications on pavement, both structurally and in terms of serviceability. As a consequence of these issues, and the concerns that several DOTs or agencies have elected to not seal pavements due to lack of compelling beneficial evidence, the Seal No Seal Group undertook this study on sealing effectiveness. Historically, this was determined by applying weighting factors to sealant condition, such as amount of adhesive and cohesive failure, missing sealant, etc. However, none of these surrogates address fundamental properties related to actual performance. With the use of GPR, it now seems 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. joint inFiLtrAtion The study characterized joint infiltration as a function of both construction quality and environmental factors. The impact of construction was assessed as a function of joint cleanliness, sealant damage, joint movement, and sealant type. The environmental factor was assessed as the predicted infiltration as a function of rainfall intensity, joint geometry, and cross slope. Three sealant types were evaluated: silicone, hot pour and compression seals. The impact of joint infiltration on pavement performance was determined by conducting laboratory tests to quantify subbase erosion, along with the development of a predictive model and supporting software. With these tools an owner can now determine the impact of sealing joints and joint condition on pavement performance. Another aspect of the study evaluated the use of GPR to detect the existence of moisture under the slabs in the vicinity of the joint. The age-old question has always been how to determine when to reseal. reAL-WorLd testing The TTI study consisted of both controlled field experiments, and testing of in-service pavements. The controlled field experiments were conducted at TTI's Riverside Campus and were designed to evaluate the effect of sealant damage and joint cleanliness on infiltration rates. Testing of in-service pavements occurred on Ill. 59 in Plainfield, Ill., and on I-10 just west of Phoenix. The purpose of testing in-service pavements was to relate sealant effectiveness - that is, infiltration rates - to actual pavement performance. The Illinois project was approximately four years old and consisted of 10 test sections which included sealed and unsealed joints. The Arizona project was an LTPP SPS-2 project which was 20 years old, and consisted of 20 test sections, including four different base types. The field testing consisted of conducting infiltration and falling weight deflectometer (FWD) testing. Limited GPR testing was also conducted at each of the sites to m-e FAuLt Prediction modeL A mechanistic-empirical fault prediction model previously developed under National Ready Mixed Concrete Association (NRMCA) funding was improved upon as part of this research. The impact of joint seal effectiveness was directly employed within the fault prediction model. One important factor that was addressed in the model was a means to evaluate the number of "wet" days. The number of wet days is the actual number of days per year that water exists underneath the slab at the slab/subbase interface. This number is not only a function of annual rainfall but also a function of surface inflow, sealant effectiveness and subbase drainability. The number of wet days was determined with respect to probability functions that can be used for each site to evaluate the number of days that water exists underneath a slab. The erosion resistance of materials, number of wet days, and traffic load were defined and coupled in this model to effectively analyze the potential for faulting and erosion in jointed concrete pavements. The model can be calibrated for local conditions as a function of distinct characteristics of the subbase or subgrade, which is an important capability in life cycle analysis. The model has been successfully implemented into a spreadsheet format. Results show that the model fits well with the field data and can be implemented for design and maintenance management purposes. Both the full report, and a shorter Tech Brief, from the TTI research may be downloaded at http://sealnoseal.org/news.htm. Fall 2016 pavement preservation journal 41 http://www.sealnoseal.org/news.htm

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