Successful cold in-place recycling around the globe

Transcription

1 Wirtgen Cold Recycler 2200 CR / 3800 CR. Successful cold in-place recycling around the globe JOBREPORTS ANDREFERENCES

2 Cold in-place recycling Economical road rehabilitation The in-situ cold recycling process is simple yet sophisti cated: the milling drum the heart of the 2200 CR / 3800 CR effectively granulates the existing asphalt pavement at a depth of up to 20 cm. The granulated material is then homogeneously mixed with injected binding agents and water in the machine s heavy-duty milling and mixing chamber to create a new mix. The newly produced mix is then deposited between the rear crawler track units via a system of baffl e plates. The spreading auger spreads the material uniformly across the full width, enabling the paving screed to place and pre-compact it with maximum precision. Following compaction by rollers, the recycled layer forms the base of the new road pavement. Different injection systems are available, depending on the binding agents used. Via hose connections, the injection systems convey the liquid binding agents from tanker trucks to the milling and mixing chamber for injection into the material to be recycled. But customers request new solutions Wirtgen offers the 2200 CR / 3800 CR cold recycler in various different confi gurations: Microprocessor-controlled pump for the addition of hot bitumen Hose connection at bitumen tanker Microprocessor-controlled pump for injecting water to produce foamed bitumen Paving screed Working direction Recycled construction material mix Spreading auger Milling and mixing rotor Damaged asphalt pavement Microprocessorcontrolled pump of WM 1000 for injecting the cement-water slurry Hose connection at WM 1000 slurry mixer

3 HD+ 120i HD+ 120i HD+ 120i HD+ 120i HD+ 120i HD+ 120i 3800 CR SUPER CR 3800 CR CR with integrated Vögele screed > Cold recycling of 100 % asphalt layer to a depth of 20 cm at a working width of 2.2 m > Cold recycling of asphalt layer plus base material to a depth of 20 cm at a working width of 2.2 m > Typical binding agents: cement, emulsion and foamed bitumen > Compact recycling train with integrated screed (especially suitable for urban job sites under traffic) CR Downcut with integrated Vögele screed > Cold recycling of 100% asphalt layer to a depth of 15 cm at a working width of 3.8 m > Recycling pavements seamlessly across the full width of the traffic lane in a single pass > Typical binding agents: emulsion and foamed bitumen > Compact recycling train with integrated screed (especially suitable for urban job sites under traffic) SUPER CR Downcut Rear Load + Vögele paver with high-compaction screed > Cold recycling of 100 % asphalt layer to a depth of 15 cm at a working width of 3.8 m > Recycling pavements seamlessly across the full width of the traffic lane in a single pass > Typical binding agents: emulsion and foamed bitumen > Unevenness of existing pavement eliminated and paved back to correct slope and grade

4 04 05 PROJECT DATA 2.2 m 10 cm Percentage foamed bitumen 1.6 % Percentage added water % Average working speed 5 m / min 2200 CR Jamieson Avenue, Los Angeles / USA First recycling width 2.2 m x 10 cm depth: all nozzles open on foam spray bar to cover width of cut. Jamieson Avenue in the North West section of Los Angeles: extensive alligator cracking with associated base failure. The street is the first location for the city s urban street cold in-place recycling program. The alternative to cold inplace recycling on this type of street would be full reconstruction, including excavating and hauling off site all in-situ materials, importing new base materials and overlaying with asphalt. The recycling train consisted of the cold recycler 2200 CR and a hot bitumen tanker. Application width of foam can be varied by closing off some of the 12 injection nozzles. The entire foam system is electrically heated to maintain bitumen temperature. The approx 7.5 m wide road required four 2.2 m wide passes with the 2200 CR including 150 mm joint overlap. The recycled material was pre-compacted by means of an integrated Vögele AB375T screed working width 2.0 m to 3.85 m. On-site problems for compaction: poor wet subgrade offering little support for conventional vibratory compaction, and residential area, close proximity to housing, need to reduce vibration emission. The Hamm HD 90 VO oscillation compactor was selected to overcome the above problems.

5 2200 CR Heida Road, Anshan / China The Shenyang San Xing Group is a strong promoter of the cold recycling technology in Northern China and commissioned the 2200 CR and the slurry mixer WM 1000 for a construction project. The project consisted of two sections in section G 202 of Heida road. The first section was re cycled by using cement, and for the second section foamed bitumen and cement were introduced in the cold recycling process. The advantage of this process is that the existing pavement structure can be milled up to a depth of 20 cm, mixed with binders and precompacted in a single pass. hot bitumen tanker and a water tanker. The savings are enormous, for in-situ cold recycling is considerably more cost-efficient than the conventional method of milling, removing the RAP, delivering new material and then placing it. The time required for a project is also cut enormously and traffic is only obstructed for a short period of time. After recycling of the complete surface by the 2200 CR, a thin wearing course was applied. In the WM 1000, the amount of cement added is determined by a microprocessor controller which continuously registers the weight and adjusts the quantity, instead of being randomly measured by hand as when using the conventional method. For the cold recycling process with foamed bitumen and cement, the complete recycling train consisted of the cold recycler 2200 CR, the slurry mixer WM 1000, a PROJECT DATA 2.2 m 15 cm Percentage cement (section 1) 4.5 % Percentage added water (section 1) % Percentage foamed bitumen (section 2) 2.5 % Percentage cement (section 2) 1.5 % Percentage added water (section 2) % Average working speed m / min

6 CR Road rehabilitation with cement, Thailand Cold recycling with cement Wirtgen cold recycling 2200 CR pushes Streumaster cement spreader SW 16 MC. For over 10 years the cold in-place recycling process with cement has been a well-established procedure for road rehabilitation in Thailand and has achieved high levels of success. The process is designed for the rehabilitation of highly distressed pavements (asphalt and asphalt / base) with the Wirtgen cold recycler 2200 CR using cement as a binding agent. Exact application rates of cement are achieved using the latest technology, the Wirtgen slurry mixer WM 1000 or Streumaster cement spreader. Mix design and preliminary pave-ment investigation are carried out by local laboratories. The WM 1000 slurry mixer is connected to the 2200 CR by means of a bar and is then pushed by the CR. The WM 1000 pre-mixes the required quantities of cement and water to form a slurry which is then injected directly into the 2200 CR mixing chamber by means of a spray bar mounted on the mixing chamber. The exact quantity of slurry is metered relative to the working speed. Alternatively the Streumaster cement spreader accurately spreads the required percentage of cement directly in front of the 2200 CR to minimize any dust emission. Water is injected into the mix by means of the 2200 CR water spray bar system. The recycled material is pre-compacted by means of the integrated Vögele screed which has a working width of 2.2 m. Final compaction is achieved using 20-t Hamm singledrum compactors. As many as 70 Wirtgen 2200 CR / WM 1000 combinations are currently in operation in Thailand on a variety of job sites. PROJECT DATA 2.2 m approx. 20 cm Percentage cement approx. 3.0 %

7 PROJECT DATA 3.8 m 15 cm Percentage cement 1.0 % Percentage foamed bitumen 2.3 % Average working speed 6 m / min Production rate 388 t / h 3800 CR Downcut Rossi Lane, City of Gilroy / USA Rossi Lane is an industrial road varying in width from 9 m to 12 m. The pavement distress showed oxidization and extensive alligator cracking, with some areas of local patching. The rehabilitation method chosen for this project was cold in-place recycling, for the following reasons: lower cost, ability to keep the road open to local business traffic and speed of operation. The mix design and pavement investigation were carried out in accordance with the Wirtgen Cold Recycling Manual and the use of the Wirtgen WLB 10 S foam lab. The existing pavement was premilled using a Wirtgen W 2100 to a depth of 5 cm. The Wirtgen 3800 CR was used for the cold in-place recycling process. The 3800 CR pushed a bitumen tanker and simultaneously milled (downcut) the pavement to the required depth, adding the design percentage of foamed bitumen plus the required percentage of compaction water (both foam and water application rate metered relative to the working speed). The recycled material was then paved to the required grade using the integrated Vögele screed. Recycling pass 1: After pre-spreading cement at a rate of 1 % by mass, the road was recycled with 2.3 % foamed bitumen and compacted, then opened to traffic. Subsequent recycling passes were performed with a 15 cm overlap at the longitudinal joint until the full pavement width was completed.

8 CR Downcut Interstate I-81, State of Virginia / USA PROJECT DATA 3.8 m 12 cm Percentage cement 1.0 % Percentage foamed bitumen 2.5 % Scope 6 km Traffic was guided past the construction site on the adjacent, previously recycled right-hand lane. As part of a total Interstate recycling project, the outer lane of Interstate 81 in Virginia was rehabilitated using cold in-place recycling. I-81 is one of the major North-South routes in eastern USA and runs through Virginia with two lanes in each direction. Therefore a fast rehabilitation process with minimum impact on traffic was required. As this 6-km section of outer lane was mainly used by passenger cars, the lane was to be recycled to a depth of 12 cm. The first step of the project was to pre-mill 5 cm of the existing pavement using a Wirtgen W 2100 milling machine. After pre-spreading 1 % cement onto the pre-milled surface, a 3800 CR equipped with a 3.8 m cutter and integrated Vögele paving screed was used to recycle the lane. The 3800 CR pushed a bitumen tanker, simultaneously granulating the existing pavement and adding the design percentage of foamed bitumen and compaction water, metered proportional to the working speed. The recycled material was then paved directly behind the CR to the required grade and pre-compacted. Final compaction of the recycled lane was achieved using Hamm HD 120 and HD 130 steel drum rollers.

9 3800 CR Downcut Redmond Ave, San Jose / USA Redmond Avenue in San Jose, California, is a highly trafficked road used by cars, buses, vans and delivery trucks. The existing pavement was in need of repair and the cold in-place recycling process was selected as the preferred method, mainly to accommodate high traffic levels. The contractor used a Wirtgen 3800 CR with integrated Vögele screed and a recycling width of 3.8 m. Before recycling the pavement, 1 % cement was prespread in front of the 3800 CR. Recycling pass 1: The 3800 CR recycled the pavement in-place to a depth of 10 cm, simultaneously adding 2.2 % foamed bitumen. The recycled material was paved directly behind the recycler using the integrated screed, and finish compaction was achieved using Hamm rollers. windrowed the milled material between the 3800 CR front tracks. This material was introduced into the mixing chamber along with the material cut by the 3800 CR, providing sufficient material to pave to a width of 4.1 m. The on-board mixing computer was adjusted to compensate for this additional material to maintain the mix design requirements. Windrow milling with the Wirtgen W 150. Recycling pass 2: This pass required a total width of 4.1 m. As the 3800 CR was fitted with a 3.8 m cutter, a Wirtgen W 150 pre-milled a section of pavement ahead of the CR and PROJECT DATA 3.8 m 10 cm Percentage cement 1.0 % Percentage foamed bitumen 2.2 % Average working speed 8.3 m / min Production rate > 400 t / h

10 CR Downcut Highway 15, Mason County / USA Optimal solution: the cold recycler 3800 CR fully complied with equipment specifications. In accordance with the Mason County bid documents, cold in-place recycling was the designated rehabilitation method for Highway 15. The existing pavement was highly distressed being some 40 years old, with extensive alligator cracking and areas of cold-mix patching. In addition, this section of the highway suffered high levels of transverse cracking which affected driving conditions. The contractor for this project selected the Wirtgen cold recycler 3800 CR with a working width of 3.8 m and integrated Vögele screed. The machine is equipped with many time- saving details. In case of excessive material building up at the screed head, for example, it is possible to hydraulically open both the right and left end gates to discharge material to the sides. MIX DESIGN RESULT The mix design and pavement investigation were carried out by the emulsion supplier. The design called for the project to be divided into

11 1 2 two sections, with a recycling depth of 75 mm for the first 3 km and a depth of 100 mm for the remaining 10 km. The emulsion content was calculated on a range of coarse to medium gradation at 2.25 % to 3.75 %. FUNCTION OF 3800 CR The 3800 CR pushed the bitumen tanker. Simultaneously the 3800 CR milled (by downcutting) the existing pavement to the required thickness, added the design percentage of emulsion proportional to the working speed and added metered amounts of compaction moisture to suit varying in-situ conditions (water taken from on-board tank). The 3800 CR paved the recycled material immediately by means of the integrated Vögele AB425T screed. No windrowing or pick-up machine or additional paver was required. Compaction was carried out right behind the screed using a Hamm HD 120 roller. 1 Operations caused only minimum disruption to traffic. 2 The 3800 CR produced a recycled, paved-toslope and pre-compacted pavement. PROJECT DATA 3.8 m 0 15 cm Percentage emulsion % Total area 93,646 m 2 Average working speed 8.5 m / min Production rate 410 t / h

12 CR Downcut Four-lane road, Toronto / Canada Existing pavement heavily cracked, particularly at intersections, extensive de-lamination of asphalt layers. The 3800 CR offers a working width of 3.8 m. In addition, the down-cutting process, in which the milling drum rotates in the machine s direction of travel, permits better control of the size of the milled asphalt material. CONSTRUCTION PLAN The project comprised the cold in-place recycling of an urban four-lane road with various turn-out lanes, center traffic islands and side drainage. The construction plan included to pre-mill the existing pavement to a depth of 10 cm using a Wirtgen milling machine W Then the base material was to be pre-pulverized to a depth of 15 cm. Obvious advantage of using the 3800 CR with 3.8 m working width: it would be possible to pulverize/recycle in a single pass without the need for pre-pulverization. After pulverizing, the base was to be stabilized to a depth of 15 cm, applying 1.0 % cement and 2.5 % foamed bitumen, and compacted. In a final step, the overlay was to be paved comprising two layers of hot-mix asphalt of 60 mm and 40 mm thickness respectively. PROJECT DATA 3.8 m 15 cm Percentage cement 1.0 % Percentage foamed bitumen 2.5 % Average working speed 8.5 m / min Production rate 610 t / h

13 FUNCTION OF 3800 CR The cold in-place train comprised two units: Wirtgen recycler 3800 CR and a bitumen tanker. The 3800 CR pushed the bitumen tanker, simultaneously milling (down-cutting) the existing pavement to the required thickness, adding the design percentage of foamed bitumen, proportional to the working speed, adding metered amounts of compaction moisture to suit varying in-situ conditions, water taken from on-board tank, and paving the recycled/ stabilized material to the design slope of 2 % by means of the integrated paving screed. RECYCLE TO CURB Urban recycling can be a challenge, in particular when working around drains, manhole covers or traffic islands. Traffic accommodation can also pose problems. The compact train of 3800 CR and bitumen tanker allows recycling right up close to any obstacles, which minimizes the need for rework and produces a uniform recycled base layer. The hydraulically opening screed end gates, for example, allow the recycled material to flow right up to an island curb or around a drain or to fill up tapers on both sides of the machine. Hydraulically opening screed end gate to allow recycled material to flow flush to curb or to allow sufficient recycled material to flow around the drain.

14 CR Rear Load East Road, Mount Auburn / USA Pass No. 2 with center line overlap: rear-loading recycling mode to Vögele paver. The existing pavement on East Road: 15 cm of asphalt /seal coat over concrete layer. The aged, oxidized pavement was in highly distressed condition: block cracking, edge failures and areas of delamination. The rehabilitation method chosen for East Road was cold in-place recycling using emulsion as the binding agent. The mix design and pavement investigation were carried out by the emulsion supplier. The recycling train consisted of a water tanker, an emulsion tanker, the cold recycler 3800 CR Rear Load and the Vögele Vision 5200 paver. The 3800 CR stabilized the pavement to a depth of 7.5 cm with 3.0 % emulsion, cutter in down-cutting mode, and loaded the recycled material directly into the receiving hopper of the Vögele paver. Final compaction was carried out right behind the paver by Hamm HD 140+ and HD 110 rollers. The recycling process on the 7 km long range was completed in two passes: pass No. 1 for the left lane, pass No. 2 for the right lane with center line overlap. So as not to double dose this overlap section with emulsion, spray nozzles 1 and 2 were switched off. PROJECT DATA 3.8 m 7.5 cm Percentage emulsion 2.3 % Average working speed 9 m / min Production rate 311 t / h

15 3800 CR Rear Load Route 17, Hampton / USA PROJECT DATA 3.8 m 12 cm Percentage cement 1.0 % Percentage foamed bitumen 2.2 % Average working speed 8.5 m / min Production rate 520 t / h The highway runs with two lanes in each direction. As a result of continuously increasing traffic volumes (approx. 15,000 vehicles per day, 3 % trucks), the pavement surface was covered with extensive areas of patching and transverse and longitudinal cracks extending throughout the pavement structure. The rehabilitation method chosen for the highway was cold in-place recycling using foamed bitumen as the binding agent. A Wirtgen WLB 10 S foam lab delivered the mix design and pavement investigation. to the Vögele Super paver. Two Hamm rollers HD 120 and HD 130 compacted the new pavement right behind the Vögele paver. Down-cutting recycling thus produced a bituminous base layer of superior quality no crushing or screening plant was required. Inside lane recycled across the full width in a single pass, with truck traffic running in the adjacent lane. First a Wirtgen milling machine W 2000 premilled the existing asphalt pavement to a depth of 5 cm. Then the compact recycling train reported for duty. Preceding tanker trucks delivered hot bitumen and water to the 3800 CR Rear Load via hose connections. The cold recycler milled off and granulated the damaged asphalt layer down to a depth of 12 cm in a single pass while the milling and mixing rotor mixed in foamed bitumen and water at the same time. The 3800 CR Rear Load forwarded the recycled material directly

16 CR Rear Load Baileysville Road, Freeport / USA After paving, Hamm HD 120, HD 130 and GRW 280 rollers compacted the new pavement. Baileysville Road in Freeport, Illinois, is a highly trafficked business road. The distressed pavement showed extensive alligator and transverse / longitudinal cracking, with irregular and unstable shoulder widths. Cold in-place recycling was selected to renew the road, mainly to accommodate high traffic levels. The contractor used a Wirtgen cold recycler 3800 CR with a recycling width of 3.8 m and foamed bitumen as the binding agent. The 3800 CR stabilized the pavement to a depth of 10 cm in a single pass and across the full width of the traffic lane, adding 2.5 % foamed bitumen and 1.5 % water (taken from on-board water tank). The 3800 CR then loaded the recycled material into the paver s receiving hopper. The efficient Vögele machine worked right behind the 3800 CR, paving the recycled material to the required grade. Final compaction of the recycled lane was achieved using Hamm rollers. Traffic was guided past the construction site on the adjacent lane. PROJECT DATA 3.8 m 10 cm Percentage foamed bitumen 2.5 % Percentage added water 1.5 % Average working speed 6.7 m / min

17 3800 CR Further reference projects North America Project: HIGHWAY 40, 2-LANE, ALBERTA, CANADA Road Authority: Ministry of Transportation, Alberta Recycling: 10 cm deep x 3.8 m wide 2.0 % emulsion Pass No: 1 of 2 Traffic: > 8,000 vehicles per day (10 % trucks) Scope: 20 km Project: LETHBRIDGE HIGHWAY, 2-LANE, ALBERTA, CANADA Road Authority: Ministry of Transportation, Alberta Recycling: 10 cm deep x 3.8 m wide 2.0 % foamed bitumen, 1.0 % cement Pass No: 1 of 4 Traffic: > 10,000 vehicles per day (10 % trucks) Scope: 60 km Project: BISHOP S HILL, 2-LANE, ILLINOIS, USA Road Authority: Henry County Recycling: 10 cm deep x 3.8 m wide 2.0 % emulsion Pass No: 1 of 2 Traffic: > 6,000 vehicles per day (5% trucks) Scope: 12 km Project: ROUTE 20, 2-LANE, ILLINOIS, USA Road Authority: Illinois Department of Transportation Recycling: 10 cm deep x 3.8 m wide 2.2 % emulsion Pass No: 1 of 2 Traffic: > 8,000 vehicles per day (8% trucks) Scope: 18 km

18 3800 CR Further reference projects North America Project: MEADOWVALE BVLD, 4-LANE, MISSISSAUGA, CANADA Road Authority: City of Mississauga Recycling: 10 cm deep x 3.8 m wide 2.5 % foamed bitumen, 1.0 % cement Pass No: 2 of 4 Traffic: > 20,000 vehicles per day (5% trucks) Scope: 12 km Project: ROUTE 19, 2-LANE, ONTARIO, CANADA Road Authority: Ministry of Transportation, Ontario, Canada Recycling: 10 cm deep x 3.8 m wide 2.2 % foamed bitumen Pass No: 1 of 2 Traffic: > 10,000 vehicles per day (10% trucks) Scope: 12 km Project: WAVERLEY, 2-LANE, MICHIGAN, USA Road Authority: City of Lansing Recycling: 12 cm deep x 3.8 m wide 2.5 % foamed bitumen, 1.0 % cement Pass No: 1 of 2 Traffic: > 5,000 vehicles per day (2% trucks) Scope: 5 km Project: MONTEREY HIGHWAY, 6-LANE, SAN JOSE, CALIFORNIA Road Authority: City of San Jose Recycling: 10 cm deep x 3.8 m wide 2.2 % foamed bitumen, 1.0 % cement 40 mm rubberized HMA Pass No: 2 of 6 Traffic: > 30,000 vehicles per day (5% trucks) Scope: 26 km

19 Project: HIGHWAY 55, 4-LANE, QUEBEC, CANADA Road Authority: Ministry of Transportation, Quebec Recycling: 12 cm deep x 3.8 m wide 2.4 % emulsion Pass No: 1 of 4 Traffic: > 40,000 vehicles per day (30% trucks) Scope: 12 km Project: HIGHWAY 9, 2-LANE, ONTARIO, CANADA Road Authority: Ministry of Transportation, Ontario, Canada Recycling: 10 cm deep x 3.8 m wide 2.2 % foamed bitumen, 1.0 % cement Pass No: 1 of 2 Traffic: > 10,000 vehicles per day (5% trucks) Scope: 18 km Project: HIGHWAY 64, 2-LANE, IOWA, USA Road Authority: Department of Transportation, Iowa Recycling: 10 cm deep x 3.8 m wide 2.4 % foamed bitumen Pass No: 1 of 2 Traffic: > 15,000 vehicles per day (8% trucks) Scope: 16 km Project: STALLINGS ROAD, 2-LANE, GEORGIA, USA Road Authority: Department of Transportation Georgia. Federal Highways and 12 State Demonstration Project Recycling: 10 cm deep x 3.8 m wide, 2.2 % emulsion Pass No: 1 of 2 Traffic: > 3,000 vehicles per day (2% trucks) Scope: 4 km

20 Illustrations and texts are non-binding and may include customized fi ttings. Subject to technical changes. Performance data depend on operational conditions. Nr EN-01/16 by Wirtgen GmbH Printed in Germany Wirtgen GmbH Reinhard-Wirtgen-Str Windhagen Germany Phone: +49 (0) / Fax: +49 (0) / Internet: info@wirtgen.com