Pavement Maintenance - Cornell Local Roads Program - Cornell ...

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Pavement Maintenance Spray patching involves the following steps. • Blow debris from the hole • Spray a tack coat of binder on the sides and bottom of the hole • Blow a mixture of aggregate and binder into the hole • Top off with a layer of uncoated aggregate, to blot the surface and prevent tracking Demand Patching (Cold patch) Demand patching is one of the most common pavement maintenance techniques. There is usually pressure to make repairs as quickly as possible. Some municipalities have a 24-hour standard for patching potholes. If the patch fails, the municipality still has a liability problem, and has to go back and refill the pothole. Demand patching restores safety, but does not repair the underlying distress. Materials Demand patching materials generally come in three different forms: • Standard cold patch or plant mix • Fiber reinforced patch material • Modified cold patch (proprietary) Materials can be prepared ahead of time and placed into stockpiles or even packed in buckets or bags. Bags of patching mix can be kept in the back of a pickup for emergency repairs. The extra weight can also help improve the vehicles traction in the winter. The optimum material is made with high quality aggregate. The binder needs to contain antistripping agents. These agents deal with the water found in many potholes which are filled in the winter and spring. The material needs to be workable at low temperatures, but still have stability under traffic. This unique combination of properties makes cold patch material difficult to manufacture. Less expensive mixes tend to either strip or have no stability under traffic. They cannot handle the traffic load placed upon them, and they fail very quickly. The first major improvement to cold patch was the addition of fibers. This improved the stability, but also increased the price. More recently, proprietary mixes with specially formulated binders have been produced. These materials can be twice as expensive as standard mixes, but may be more cost effective, due to a higher success rate. Proprietary mixes are bid out by the New York State Office of General Services (OGS). New products are being developed all the time, so a comprehensive list of materials cannot be easily produced. Table 8 lists the proprietary cold patch products bid out in 2005 via OGS. 44 Cornell Local Roads Program Figure 27 – Self-contained spray patch truck
Table 8 - Proprietary cold patches on NYS OGS bids, 2005 Patch name Producer or manufacturer BOND X Seaboard Asphalt Products, Inc. DURO PATCH Gorman Bros. HYPERPATCH Vestal Asphalt, Inc. I.A.R. I.M.U.S., Inc. MAC-V Midland Asphalt Corp. MC-400P Koch Materials Co. NORJOHN SPC Norjohn Ltd. OPTIMIX Optimix, Inc. PARCO PATCH Peckham Materials Corp. PERFORMIX Seaboard Asphalt Products QPR QPR, A Division Of Lafarge N.A. S-K MOD Suit-Kote Corp. SYLCRETE EV Sylcrete Corp. TOP MIX Tech Mix UPM Unique Paving Materials 7 - Patching There are differences between the various proprietary cold patch materials. Some work better in cold weather, some are easier to finish, some are more forgiving under traffic. When choosing which material to use, price is not usually a significant factor. All of the proprietary materials are similar in price. The one you should use is the one which will work properly in your conditions. Repair technique Cold patch should be compacted with a roller or a plate tamper, but in practice it is rarely done. Speed of repair is the primary reason for this, which has earned the technique the name “Throw and Go.” The problem with Throw and Go is that the lack of compaction causes the material to fail very quickly. Patches placed one day are often gone the next. A more effective technique is “Throw and Roll.” The only difference is that the truck is used to compact the mix. Truck tires do a fairly good job of compacting the mix. With compaction, more patches will survive the season. The steps of Throw and Roll are listed on the next page. The production speed of Throw and Roll is not much less than Throw and Go. Rolling over the patch typically increases the survival rate (the number of patches that will survive the season) from 10 to 25 percent . Using a proprietary mix, as opposed to a standard cold patch, can double the survival rate to 50 percent. Cornell Local Roads Program 45
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Pavement Maintenance Cornell Local
Page 5 and 6: PREFACE Millions of dollars are spe
Page 7 and 8: TABLE OF CONTENTS Chapter 1. Introd
Page 9: List of Tables Table 1 Average dist
Page 12 and 13: Pavement Maintenance Table 1 - Aver
Page 15 and 16: 2 - Why Roads Fail Prematurely ____
Page 17 and 18: 2 - Why Roads Fail Prematurely Gene
Page 19 and 20: 2 - Why Roads Fail Prematurely Usin
Page 21: 2 - Why Roads Fail Prematurely Main
Page 24 and 25: Pavement Maintenance Thin wearing c
Page 27 and 28: 4 - Pavement Distresses ___________
Page 29 and 30: Figure 5 - Sealed longitudinal crac
Page 31 and 32: Edge cracking 4 - Pavement Distress
Page 33 and 34: Figure 10 - Shoving of asphalt surf
Page 35 and 36: Surface defects 4 - Pavement Distre
Page 37: Figure 15 - Overlay delamination 4
Page 40 and 41: Pavement Maintenance Preventive mai
Page 42 and 43: Pavement Maintenance Table 4 - Pave
Page 44 and 45: Pavement Maintenance Table 5 shows
Page 46 and 47: Pavement Maintenance Flush-fill The
Page 48 and 49: Pavement Maintenance Cracks should
Page 50 and 51: Pavement Maintenance Material finis
Page 52 and 53: Pavement Maintenance Construction o
Page 56 and 57: Pavement Maintenance “Throw and R
Page 58 and 59: Pavement Maintenance Table 10 - Dis
Page 60 and 61: Pavement Maintenance Micropaving Mi
Page 62 and 63: Pavement Maintenance Toughness The
Page 64 and 65: Pavement Maintenance For use in thi
Page 66 and 67: Pavement Maintenance Residual Aspha
Page 68 and 69: Pavement Maintenance Table 14 - Emu
Page 70 and 71: Pavement Maintenance To calibrate t
Page 73 and 74: APPENDIX A - CRACK TREATMENT MATERI
Page 75 and 76: APPENDIX C - VIDEOS The following v
Page 77 and 78: New York State Conference of Mayors
Page 79 and 80: APPENDIX F - GLOSSARY AASHTO - Amer
Page 81: Appendix F - Glossary Pavement Reha
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