DRAFT. Evaluation of Joint Sealant Materials, US-36, Doniphan County, Kansas. Report No. FHWA-KS-08-2

Transcription

1 Report No. FHWA-KS-08-2 final REPORT Evaluation of Joint Sealant Materials, US-36, Doniphan County, Kansas Rodney A. Montney, P.E. Robert F. Heinen John Wojakowski, P.E. Kansas Department of Transportation Topeka, Kansas June 2009 KANSAS DEPARTMENT OF TRANSPORTATION Division of Operations Bureau of Materials and Research

2 1 Report No. FHWA-KS Title and Subtitle Evaluation of Joint Sealant Materials, US-36, Doniphan County, Kansas 2 Government Accession No. 3 Recipient Catalog No. 5 Report Date June Performing Organization Code 7 Author(s) Rodney A. Montney, P.E., Robert F. Heinen, John Wojakowski, P.E. 9 Performing Organization Name and Address Kansas Department of Transportation Bureau of Materials and Research 700 SW Harrison Street Topeka, Kansas Sponsoring Agency Name and Address Kansas Department of Transportation Bureau of Materials and Research 700 SW Harrison Street Topeka, Kansas Supplementary Notes For more information write to address in block 9. 8 Performing Organization Report No. FHWA-KS Work Unit No. (TRAIS) 11 Contract or Grant No. 13 Type of Report and Period Covered Final Report Spring Sponsoring Agency Code RE Abstract The Kansas Department of Transportation began using silicone joint sealant on Portland Cement Concrete Pavement (PCCP) almost exclusively in During the next 6 years there was widespread failure of these products. A project was constructed in 1990 to evaluate several different types of joint sealants available. While most of the silicone products in this study appeared to outperform the other types, KDOT could not ignore the failure rate of the previously installed silicone sealants. During the course of this investigation, KDOT issued a policy on sealing new PCCP joints. The policy requires preformed neoprene seals in all transverse joints, and allows longitudinal joints to be filled full depth with either hot or cold pour sealants. 17 Key Words Joint Sealant, Concrete Pavement 19 Security Classification (of this report) Unclassified Form DOT F (8-72) 20 Security Classification (of this page) Unclassified 18 Distribution Statement No restrictions. This document is available to the public through the National Technical Information Service, Springfield, Virginia No. of pages 22 Price 15

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4 Evaluation of Joint Sealant Materials, US-36, Doniphan County, Kansas Final Report Prepared by Rodney A. Montney, P.E. Robert F. Heinen John Wojakowski, P.E., Retired Kansas Department of Transportation Topeka, Kansas A Report on Research Sponsored By THE KANSAS DEPARTMENT OF TRANSPORTATION TOPEKA, KANSAS June 2009 Copyright 2009, Kansas Department of Transportation

5 NOTICE The authors and the state of Kansas do not endorse products or manufacturers. Trade and manufacturers names appear herein solely because they are considered essential to the object of this report. This information is available in alternative accessible formats. To obtain an alternative format, contact the Office of Transportation Information, Kansas Department of Transportation, 700 SW Harrison Street, Topeka, Kansas or phone (785) (Voice) (TDD). DISCLAIMER The contents of this report reflect the views of the authors who are responsible for the facts and accuracy of the data presented herein. The contents do not necessarily reflect the views or the policies of the state of Kansas. This report does not constitute a standard, specification or regulation. ii

6 ACKNOWLEDGEMENTS The Kansas Department of Transportation would like to thank the manufactures of the various products used on this project and their representatives for participating in the installation of their products. EXECUTIVE SUMMARY The Kansas Department of Transportation has over the years used various forms of joint sealant in Portland Cement Concrete Pavements. At the time this study was initiated, the predominant product was silicone joint sealants. Over a six year period, there was an extensive failure rate of these sealants with most of the silicone being removed from the joints under normal traffic conditions. KDOT decided to re-evaluate previously used sealants along with several sealants that had not previously been used in Kansas and sealants that were new to the market. iii

7 TABLE OF CONTENTS ACKNOWLEDGEMENTS... iii EXECUTIVE SUMMARY... iii INTRODUCTION... 1 TESTING... 3 CONCLUSION... 7 iv

8 INTRODUCTION In 1983 the Kansas Department of Transportation began using silicone almost exclusively as its only joint sealant for Portland Cement Concrete Pavements. By 1989, it was estimated that 1 million lineal feet of the silicone joint sealants had failed, and it was decided to re-evaluate some of our former, non-silicone, sealants and evaluate sealants not previously used by KDOT. In 1990, 18 different joint sealants were installed on a 14 mile project on US-36 in Doniphan County, Kansas. Five of these sealants were new to the marketplace. The manufacturers representatives were present at the time of construction. The pavement was 8 plain PCCP with 15 skewed joints, and was built on a drainable base. No dowel bars were used for load transfer. The transverse joints were made by both conventional sawing and the use of two piece parting strips. A recap of the materials used is listed in the following table. 1

9 Product Manufacturer Number of Joints Years to Vacuum Failure Dow 890 SL Dow Corning Dow 888 SL Dow Corning Dow 888 Sawed Joint Dow Corning 20 8 Dow 888 Formed Joint Dow Corning 20 8 Sof-Seal (Cold Applied) Sawed Joint W.R. Meadows Sof-Seal (Cold Applied) Formed Joint W.R. Meadows Road Saver Silicone Crafco Baysilone 960 Mobay Corp Neoprene Preformed D. S. Brown 20 5 Crafco 221 Crafco 20 4 Koch 9005 Koch 20 4 Hi-Spec W.R. Meadows 20 4 Crafco 231 (modified) Crafco 20 5 Koch 9030 (modified) Koch 20 4 Sof-Seal (hot applied) W.R. Meadows 20 4 New Experimental Joint Sealant Materials Product Manufacturer Number of Joints Sikaflex 15LM Sika 20 8 Koch UV Cure E88 Formed Joint Koch 10 5 Koch UV Cure E77 Formed Joint Koch 10 4 Koch UV Cure Formed Joint Koch 16 1 Koch Polysulfide Formed Joint Koch 8 1 Koch Polysulfide Formed Joint Koch 5 1 The Dow 890 SL, 888 SL, and 888, Road Saver, and Baysilone 960 were all silicone joint sealants. Sof-Seal (cold applied) is a cold applied soft sealant. Neoprene is a preformed elastomeric compression joint seal meeting AASHTO M-220. Crafco 221, Koch 9055, and Hi-Spec were all hot type low modulus asphaltic joint sealants that conformed to KDOT s maintenance specifications (TS-109). Crafco 231, Koch 9030, and Sof-Seal (hot applied) were all asphaltic materials meeting ASTM D The Sikaflex 15 LM is cold applied polyurethane. All the manufacturers had representatives on hand to oversee the installation of their products in the joints. 2

10 TESTING The joint sealants were tested by application of a vacuum of 10 of mercury to a two foot long box with a clear top that covered the joint. A soap solution was first applied to the joint to give visual indication of the size and location of leaks. Vacuum was applied that pulled the padded edge of the box tightly to the pavement. The size of the bubbles (none, very tiny, tiny, medium, or large) was observed and recorded. Two readings were taken at each joint, one reading in each wheel path. The number of years until the sealant could no longer hold a vacuum is also included in the Table on the previous page. The first year of the study, three of the joint sealants that were new to the marketplace failed to hold a vacuum. Koch UV Cure and both of the Koch Polysulfides failed to hold a vacuum in By 1994, Koch UV Cure 77, Crafco 221, Koch 9005, Hi-Spec, Koch 9030 modified, and Soft Seal (hot applied) had failed to hold a vacuum. In 1995 Crafco 231, Koch UV Cure 88, and the Neoprene were essentially unable to hold a vacuum. All of the hot type low modulus asphaltic joint sealants (KDOT maintenance specifications), the Neoprene, and all those meeting ASTM D-3405 had failed to hold a vacuum within the first 5 years of the project. The only new experimental joint sealant that was still performing in 1995 was Sikaflex 15 LM. After the second year, faulting measurements were taken on each test section. The graph on the next page illustrates the faulting measurements for the years 1994 (4) through 2003 (13). The areas of greatest faulting were diamond ground in 1999, and full depth patching was also done on broke panels. The sealants were removed from all test sections and replaced with a low modulus hot pour sealant conforming to KDOT s 3

11 maintenance specifications (TS-109). In 2004 a dowel bar retrofit was performed on this project and no further data was collected. Even though the Neoprene sealants were no longer able to hold a vacuum after 5 years, they preformed quite well in controlling the faulting of the non-dowel jointed pavement when compared to the other sealants that had failed to hold a vacuum. They were also quite effective in keeping incompressibles out of the joints. As expected, the faulting increased annually in all sections after the placement of the TS-109 sealant. No undersealing was used on the joints, so the sections that had demonstrated the most faulting before the diamond grinding also demonstrated the most faulting in the subsequent years after diamond grinding. 4

12 Original Sealants SIL is the group of all five silicones. 15LM is Sikaflex 15LM, a cold applied polyurethane. SS COLD is Cold Applied Sof-Seal. NPRENE is Preformed Elastomeric Compression Joint Seal meeting AASHTO M220. 5

13 109.6 is a group of three hot type low modulus asphaltic joint sealants meeting a Kansas maintenance specification is a group of three asphaltic materials meeting ASTM D Open are the Koch UV Cure and both of the Koch Polysulfides that failed to hold a vacuum after the first year. 6

14 CONCLUSION The silicone and other cold applied, chemically cured joint sealants that were applied during this research project performed better than historical data would indicate from KDOT s construction projects. This discrepancy can be attributed to the additional care that was taken during this research project in the sealant installation process. Representatives from the manufacturer were present and closely scrutinized the joint cleaning and sealant installations. They held the vacuum longer than the other sealants and prevented faulting of the non-doweled pavement for a longer period of time. However, the extraordinary failure rate of silicone sealants on KDOT projects could not be ignored. In 1994, KDOT issued a Joint Seal Policy on New PCCP. The policy required neoprene seals in all transverse joints, and full depth hot or cold pour sealants in longitudinal joints. This policy was somewhat based on the performance of the neoprene during the first four years of this study and previous performance of the products in Kansas. Normal traffic conditions remove the cold applied chemically cured sealants from the joints, while friction and compression keeps the neoprene products in the joint longer to repel incompressibles. 7

15 PARTMEN E D. RTATION PO F TRANS O T KANSAS.