Cold In-Place Recycling with Expanded Asphalt B-335 COLD IN-PLACE RECYCLING WITH EXPANDED ASPHALT OPSS 335

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1 B-335 COLD IN-PLACE RECYCLING WITH EXPANDED ASPHALT OPSS GENERAL Use of Cold In-Place Recycled Expanded Asphalt Mix (CIREAM) is recommended by the Regional Geotechnical Section on a work-project specific basis. CIREAM means partial depth milling the existing asphalt pavement, sizing, mixing with expanded (foam) asphalt, relaying and compacting the recycled cold bituminous mixture in-place in one single operation. CIREAM can rehabilitate pavement exhibiting age, thermal, fatigue and reflective cracking. CIREAM should be considered for roads that are severely cracked but structurally sound. It is not limited to pavements exhibiting surficial distresses. The existing pavement thickness should be at least 100 mm. CIREAM helps to retard reflection cracking and localized roughness. CIREAM is not suitable for pavements with extensive base or subbase problems, or pavements of insufficient strength. CIREAM is more suited for roads with moderate traffic volumes (AADT < 15,000 / 2 lanes). Heavy traffic is not recommended on CIREAM mix before it has cured and been sealed with a wearing course. CIREAM treatment depths range from 75 mm to 125 mm. The depth of CIREAM treatment shall be selected to minimize disturbance of the underlying granular base. It is recommended to have a minimum of 25 mm existing pavement remaining below the CIREAM. Pavements that contain asbestos, geogrid, glasgrid, or layers with rich asphalt content, HL 2 may be difficult to CIREAM. CIREAM is not suitable for structurally deficient pavements, ie, lack of structural capacity, severe distortions and / or instability rutting. Pavements that have the following maintenance treatments may be considered since they have no detrimental effects on the CIREAM mix design. - Cold mix patching - Spray patching - Chip seal January 2010 Pg. 1 of 6 B335

2 The benefits of CIREAM are: - The mix is flexible with high air voids, so reflection cracking is notably reduced - The mix curing time is significantly shorter than CIR - Uses 100% of reclaimed material - Traffic is allowed back on within one hour of its placement REFERENCES none TENDER ITEMS Cold In-Place Recycled Expanded Asphalt Mix SPECIFICATIONS Application details for the above tender item are found in OPSS SPECIAL PROVISIONS Refer to Chapter E of this manual to review the applicable standard special provisions. A special provision is required if crack sealant is to be removed STANDARD DRAWINGS - none DESIGN Geotechnical Design Considerations The cold mix is susceptible to moisture intrusion and abrasion. It requires that a separate wearing surface such as hot mix overlay, surface treatment, or microsurfacing be placed over to seal the CIREAM during the same construction season. To date, surface treatment and micro-surfacing have not been used as the separate wearing surface. January 2010 Pg. 2 of 6 B335

3 A tack coat is required prior to Hot Mix Asphalt (HMA) paving over all areas of CIREAM. The Tack Coat rate of application that corresponds to cold in-place recycled surfaces shall be used. Reference is made to CDED Section B308, Tack Coat, for administration of this tender item. When sealed transverse cracks are spaced at a frequency of less than 10 m and/or extensively sealed longitudinal cracks exist, all cracks must be identified in the contract for complete sealant removal prior to CIREAM. This is due to the problems experienced on some past Cold In-Place Recycling (CIR) contracts with aggregate located above CIR sealant pieces popping off. Estimation of quantity to be removed should be included in Pavement Design Report. In urban areas, the designer should be aware of appurtenance adjustment requirements, curb heights, and accessibility concerns to accommodate the CIREAM equipment train and the requirement for traffic detours. At intersections, the main lanes and turn lanes of significant length (greater than 300 m) should be CIREAM. Different treatments (ie, remove and replace with acceptable binder course HMA) may be applied to shorter turn tapers, entrances, etc. CIREAM should only be considered for daylight operations due to traffic control and safety concerns. The designer should be aware that the length of the CIREAM paving operation may affect traffic management. Any full depth repairs required for frost heave and distortion corrections should be repaired prior to CIREAM. Full depth repairs are to be managed elsewhere in the contract. A tender item for restoring a roadway surface prior to covering the CIREAM with wearing course may be required. Refer to Section B301 of this manual for detail estimating and documentation on Restoring Roadway Surfaces. For design purposes CIREAM with an overlay should be compared to the following conventional technique to address nonstructural surficial distresses: 40 mm Superpave 12.5 over 100 mm CIREAM Vs. Full depth reclamation, (FDR), 40 mm Superpave 12.5 over two 50 mm lifts of Superpave 19.0 January 2010 Pg. 3 of 6 B335

4 Pre-Engineering Investigation General: This section describes procedures and tests to be carried out during preengineering contract investigations on potential Ministry CIREAM projects. It is recommended that adequate pre-engineering be carried out to establish existing pavement thicknesses and composition. Additional investigation should be carried out where pavement composition changes, such as patched areas. This information is required for the Geotechnical Engineer to determine whether the existing pavement, on potential projects meets the minimum thickness requirement in addition to assisting the designer in selecting a depth of CIREAM. Field investigation to determine the present pavement condition and distress manifestations. Estimating of quantity of sealant to be removed should be included in Pavement Design Report. Selection of Coring Locations: 1. A minimum of one core location per kilometer. 2. Cores shall be taken not less than 0.5 m from the edges of the pavement of the main lanes and in areas representative of the overall pavement condition. Core location should be random. 3. Cores should extend to the bottom of the lower hot mix lift. 4. Testing on cores should be conducted to determine stripping potential, existing asphalt cement content, and mix design requirements for optimum expanded asphalt required. The information does not relieve the Contractor from obtaining cores to determine emulsion quantities and compaction for the CIREAM material Other Design Considerations The CIREAM specification requires the use of a pilot vehicle as part of the process. The regional traffic section should be consulted regarding the deletion of the pilot vehicle requirement if it is on a freeway. The pilot vehicle requirement can be deleted by use of a standard special provision COMPUTATION Source of Information January 2010 Pg. 4 of 6 B335

5 All paving requirements of a project with respect to sealant removal, hot mix requirements, CIREAM depths, asphalt core analysis and test results including treatment of shoulders as recommended by the Regional Geotechnical Section are stated in the Pavement Design Report Method of Calculation Cold In-Place Recycled Expanded Asphalt Mix is a Plan Quantity Payment item. The unit of measurement for CIREAM is square meters. The Contractor is responsible for the CIREAM mix design and will supply asphalt cement, as required, on all contracts for the CIREAM. No quantity calculations are required by the designer for this material. The estimated bulk relative density of CIREAM is 2.20 t/m DOCUMENTATION It is necessary to ensure that the following information is indicated for all CIREAM to be carried out on a project and must include the depths of CIREAM and the hot mix overlays for the roadway, private and commercial entrances, side roads, tapers, interchange ramps, pavement widening, paved shoulders, partial paved shoulders, and any other miscellaneous areas to be paved. The designer shall specify the following in the Contract Documents: 1. For the item CIREAM, typical cross sections which show normal sectional requirements are to be included. Include on sections the required processing depth of CIREAM. The drawings are the only place where this information is available to the Contractor. 2. The thickness of CIREAM is indicated in the column heading on the Miscellaneous Quantity sheet. 3. Each area quantity of CIREAM is shown on one row of the Miscellaneous Quantity Sheet. For each area, indicate both start and end chainage in the location and position column. Width of pavement or offsets left and right are provided in the comments column. 4. For each interval indicated by start and end chainage on the Quantity Sheet, indicate in the Comments column the estimated quantity of crack sealant which is to be removed in linear metres. These removals are included for payment under the CIREAM tender item. January 2010 Pg. 5 of 6 B335

6 5. For areas inaccessible to the CIREAM equipment, hot mix is required. These areas are identified and quantified (square metre) in the comments column of the Miscellaneous Quantity Sheet and paid for under the appropriate hot mix item (refer to B-313) Documentation Accuracy Calculated CIREAM quantity in square metres is recorded to the nearest whole number. Crack Sealant removal quantities in linear metres are recorded to the nearest whole number. Stations are recorded in whole number metres. January 2010 Pg. 6 of 6 B335