Multi-Layer Systems By Vadim Kravtsov Intermountain Slurry Seal, Inc 1 What Are Multi-Layer Systems? 2 A combination of pavement preservation tools designed to address distressed roadways which are past the point of a single preservation treatment 3 Result of Scheduled Pavement Preservation Systems 4 But What are Our Options Here? 5 Some Examples of Multi-Layer Systems Chip Seal Over Fabric Double Chip Seal Double Slurry/Micro Asphalt Rubber Cape Seal S.A.M.I. Three Layer System 6 Chip Over Fabric Meant to treat fair-to-moderately cracked pavements Ideal for roads where the coarse texture of Chip Seal will not be an issue Purpose of the fabric interlayer is to mitigate and prevent reflective cracking 7 Chip Over Fabric Process Roadway needs to be thoroughly cleaned, all weeds removed PG Asphalt placed at average gallons per yd, depending on pavement texture/condition Fabric placed directly behind the PG Asphalt Emulsion Chip Seal applied Option to place Slurry Seal or Fog Seal on top 8 Fabric Placement 9 Chip Application Following Behind 10 Fabric Alongside Chip 11 Double Chip Seal Ideal for Highways or County Roads. Residential? Designed to treat fair-to-moderately cracked roadway Offers skid resistance with a long service life Can consist of multiple applications of AR, modified binder, or conventional emulsion Chip Seals Both applications are performed by same crew, minimizing mobilization costs 12 Basics of Double Chip Before application road needs to be prepped, cleaned thoroughly, weeds removed 1st application placed with larger aggregate 3/8 or 1/2 gradation typically Cured and is swept 2nd application varying shot rate, aggregate gradation 3/8 1/4 ? Fog seal or slurry/micro over the top 13 Double Slurry/Micro Can be used in a wide range of roadways, residential, collectors, arterial Can expect longer performance than a single application Combines the benefits offered by the heavier application of a Type III with the aesthetically appealing finish of a Type I Both applications can be performed by the same crew, but you must allow for the proper cure time 14 Cape Seal Developed in South Africa by the Cape of Good Hope Provincial Administration in the 1950s Very widely used successfully by many agencies since the 1970s as a solution to treat whole neighborhoods annually, as part of a preservation plan. A Cape Seal is the application of any type of Chip Seal followed by one or more layers of a Slurry Seal or Micro Surfacing Cape Seal combines the advantages of two sealing preventative maintenance methods Ideal for residential neighborhoods that call for a smoother texture than Chip Seal The Slurry/Micro application increases chip retention. 15 Chip Seal Placed 16 Followed By Slurry or Micro 17 Cape Seal in Action 18 Cape Seal Finish 19 S.A.M.I. Stress Absorbing Membrane Interlayer Heavy travelled arterials and freeways Extends pavement life Reduces premature cracking Asphalt Rubber Chip Seal acts to mitigate reflective cracking 20 Edge Plane and Raise Utilities to Grade 21 Asphalt Rubber Application 22 Coated Aggregate Application 23 RHMA or HMA Overlay 24 Benefits of the Three Layer System Cost effective alternative to total rehab Shorter construction time Reduced prep work, a lot of the rutting and ride quality issues can be resolved with a rut fill, or leveling course application Environmental benefits: Very low impact on environmentally sensitive areas Recycled tire rubber is a large component of the AR binder Broad range of uses residential, arterial, county 25 Three Layer System Prior to first lift roadway is cleaned, weeds removed 1st Layer: Typically consists of a Type III leveling course, or rut fill (may take multiple lifts to correct rutting and improve ride quality) 2nd Layer: Asphalt Rubber Chip Seal is placed yd shot rate, lbs yd 3rd Layer: Cap the first two lifts with a Type II Slurry Seal or Micro Surfacing 26 Before 27 Micro Leveling 28 AR Three Layer Cape Seal Sacramento AR Chip Seal 29 Type 2 Slurry Finish 30 Which System Is Right For Me? 31 Things to consider when deciding which system is right for you Budget Material sources Condition of the road Climate 32 QUESTIONS? 33