Crack and Concrete Deck Sealant Performance A THESIS SUMITTED TO THE FACULTY OF THE UNIVERSITY OF MINNESOTA BY Karl Andrew Johnson IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF MASTERS OF SCIENCE Arturo E. Schultz, Catherine E. Wolfgram French May 2013 © Karl Andrew Johnson 2013 Table of Contents List of Tables .................................................................................................................... vii List of Figures .................................................................................................................. viii Executive Summary ............................................................................................................ 1 SECTION I – LITERATURE REVIEW ...................................................................... 10 Part A – Deck Sealants ................................................................................................... 10 1. Background ................................................................................................................. 11 1.1 Classifications ............................................................................................................. 11 1.1.1 Penetrating Sealants ................................................................................................ 11 1.1.2 Film Formers ........................................................................................................... 15 1.2 Performance Measures ................................................................................................ 15 1.2.1 Chloride Ingress....................................................................................................... 16 1.2.2 Absorption ................................................................................................................ 18 1.2.3 Depth of Penetration ................................................................................................ 19 1.2.4 Vapor Permeability .................................................................................................. 21 2. Analyzing Performance Measure Data ..................................................................... 22 2.1 Scatter in Data ............................................................................................................. 22 2.2 Correlation between Performance Measures .............................................................. 23 2.3 Effect of Differences in Test Procedure ...................................................................... 27 3. Best Performers ........................................................................................................... 30 3.1 Chloride Ingress .......................................................................................................... 31 3.2 Absorption................................................................................................................... 42 3.3 Penetration Depth........................................................................................................ 43 3.4 Vapor Transmission .................................................................................................... 48 4. Variables Affecting Performance .............................................................................. 49 4.1 Concrete Parameters ................................................................................................... 49 i 4.1.1 Moisture Content at Time of Sealer Application ..................................................... 50 4.1.2 Water Cement Ratio ................................................................................................. 51 4.2 Concrete Finishing and Curing ................................................................................... 52 4.2.1 Finish: Tined vs. Smooth.......................................................................................... 52 4.2.2 Implementation of Curing Comounds ...................................................................... 52 4.3 Surface Preparation ..................................................................................................... 53 4.4 Coverage Rate ............................................................................................................. 53 4.5 Drying Time after Coating .......................................................................................... 54 4.6 Abrasion ...................................................................................................................... 54 4.7 Freeze-Thaw Exposure ............................................................................................... 56 4.8 Field Parameters .......................................................................................................... 58 4.8.1 Environmental Conditions at Time of Sealer Application ....................................... 58 4.8.2 Repeated Impact of Traffic....................................................................................... 59 5. Reapplication ............................................................................................................... 59 Part B – Crack Sealers ................................................................................................... 61 6. Background ................................................................................................................. 62 6.1 Generic Products ......................................................................................................... 62 6.2 Primary Performance Measures .................................................................................. 64 6.2.1 Depth of Penetration ................................................................................................ 64 6.2.2 Bond Strength........................................................................................................... 65 6.2.3 Seepage .................................................................................................................... 67 6.2.4 Chloride Ingress and Corrosion .............................................................................. 67 7. Performance ................................................................................................................ 69 7.1 Depth of Penetration ................................................................................................... 69 7.2 Bond Strength ............................................................................................................. 73 7.2.1 Type of Failure ......................................................................................................... 73 7.2.2 Effect of Increasing Crack Width ............................................................................. 76 7.2.3 Effect of Freeze-Thaw Exposure .............................................................................. 78 ii 7.2.4 General Performance............................................................................................... 80 7.3 Seepage ....................................................................................................................... 82 7.4 Chloride Ingress and Corrosion .................................................................................. 84 7.4.1 Increased Chloride Concentration Locations .......................................................... 84 7.4.2 Trapping Chlorides in the Deck ............................................................................... 86 7.4.3 General Performance............................................................................................... 87 8. General Trends............................................................................................................ 89 8.1 Lifespan of Sealed Cracks .......................................................................................... 89 8.2 Ocurrence of Re-Cracking .......................................................................................... 91 8.3 Track Free Time for Sealers ....................................................................................... 92 9. Variables Affecting Performance .............................................................................. 93 9.1 Effect of Temperature ................................................................................................. 93 9.2 Effect of Moisture ....................................................................................................... 94 9.3 Effect of Cleaning Cracks ........................................................................................... 95 9.4 Effect of Crack Age .................................................................................................... 95 9.5 Temperature Effect on Crack Width ........................................................................... 96 9.6 Type of Initiator Used (for HMWM products) ........................................................... 96 10. Reapplication ............................................................................................................. 98 SECTION II – PERFORMANCE SURVEY AND CHLORIDE STUDY ................ 99 Part A – Preformance Survey ....................................................................................... 99 11. Introduction ............................................................................................................. 100 12. Materials Used ........................................................................................................