Each year, since 1985, ARRA has presented special recognition awards to deserving public officials and consulting engineers for their overall professional contribution to and their recognition and their promotion of the asphalt recycling & reclaiming industry. During its 37th Annual Meeting, in Indian Wells, California, in February, the Asphalt Recycling & Reclaiming Association (ARRA) announced the recipients of its 2013 awards:
ARRA 2013 Charles R. Valentine Award for Excellence in Cold In-Place Recycling
Mike Neil, Director of Construction Support Services, Engineering and Operations Tara Liske, Surfacing Materials Engineer, Engineering and Operations Manitoba Infrastructure and Transportation
Mike Neil and Tara Liske work within Manitoba Infrastructure and Transportation’s (MIT’s) Engineering Operations Branch. Mike is Director of Construction Support Services at MIT and is responsible for leading multiple sections: Quality Assurance, Grading and Audit, Geomatics and Civil Design, and Training Development and Recruitment Section. Tara is a Surfacing Materials Engineer and is responsible for the management and provision of technical expertise related to the design, specifications, and performance evaluation of surfacing construction materials used by the department for highway construction and maintenance. Together, Mike and Tara worked diligently over the past several years in researching recycling methods, instituting standards and specifications, educating stakeholders, and implementing Cold In-Place Recycling with Expanded Asphalt Mix (CIREAM) at the project level. Engaging staff and industry partners, candidate selection, and technical challenges in the field were three major challenges overcome in instituting the recycling process in Manitoba. Their dedication paid off in the implementation of an initial project in The Pas in 2010, followed by two more jobs in Grand Rapids and Brandon in 2012.
In their initial investigation of the recycling process, Make and Tara were intrigued by CIREAM’s robust nature, its ability to help minimize reflective cracking, and the financial and environmental savings resulting from reduced production and haulage of virgin aggregate and recycled asphalt cement. The pair also wanted to stimulate a progressive, innovative atmosphere at MIT and to expand their toolbox of rehabilitation processes. Since 2007, Mike has been involved with a committee developing draft standards for CIR, reviewing both CIR and CIREAM specs, as well as criteria for candidate selection. He also assisted with workshops and helped develop and review specifications for the process. Tara hosted workshops, helped develop lab and field testing procedures and reviewed test results during construction.
Collaboration and education were paramount to Mike and Tara’s success. Communication with members from both the Alberta and Ontario Ministries of Transportation, and research into these organizations’ existing standards allowed for the creation of Manitoba’s own specifications. Important technical and practical knowledge was gleaned from CIR contractors and other industry members in the pre-bidding process in 2010, resulting in refinement of specifications and the advancement and success of work to date. Explaining and persuading executive and regional staff of asphalt recycling’s net benefits proved to be a considerable challenge. A workshop was hosted in order to overcome any skepticism surrounding asphalt recycling practices. An initial workshop hosted in November 2009 included two industry representatives who explained In-Place Recycling in detail to all levels of staff at MIT. This workshop gained attention from executive members at MIT and enabled the team to move forward with candidate selection. After the workshop, a working group with staff from different regions, construction support services, and materials engineering, worked together to finalize specifications and generate tender documents. This working group was fundamental for completing the final stages of process implementation at the pre project stage.
Initiating recycling at the project level provided another challenge – finding a suitable project candidate. This proved difficult as many road sites were outside of the remediation capabilities of CIR treatment. Many roads were too complex to be used as a pilot for CIR. Some candidates had sub-base and subgrade issues that would have to be addressed during construction. Others were constructed with an existing base layer between layers of asphalt, commonly referred to as “sandwich” construction, which ARRA Award Winners would create technical issues for a CIR project. After encouraging regional branches to follow CIR selection criteria established by the MIT committee in 2007, a candidate was found between PR 282 and the Pas, on PTH 10.
Although the Pas was a good candidate, remediating this 32 kilometer (20 mile) stretch of roadway introduced further challenges. The site was located 633 kilometers (393 miles) North West of the City of Winnipeg, about a 7 ½ hour haul for the asphalt cement (AC) tankers. Keeping the AC at 302°F was crucial in order to achieve proper mix consistency and heated storage had to be specified in the contract as a requirement to ensure that this condition was achieved. Another challenge was the inclement weather in this area. The Pas is prone to experiencing frequent rain events and cooler temperatures in late summer and early fall, increasing the possibility of the CIR mat experiencing higher moisture content prior to hot mix paving. This weighed heavily in MIT’s decision to proceed with CIREAM as opposed to
CIR with emulsion, as the curing time is shorter, which allowed the contractor to lay hot mix asphalt sooner after reclamation. Specifications were modified to limit moisture content to less than 4% and tests were conducted to determine moisture increases after rain events on the exposed CIR mat. Initially, two compaction units were used on the project. A third unit was added midway through the job and testing was conducted to determine increases in compacted density. Results indicated that the addition of the third roller provided superior compaction of the mat and a third roller was specified and permanently incorporated into subsequent work in Brandon and Grand Rapids. The addition of a third roller also mitigated undue increased moisture issue by producing a tighter, better sealed mat.
Recycling of existing aggregate and asphalt cement along with reductions in fuel usage allowed for substantial financial and environmental cost savings. Specifically, there was a total financial savings of $1.9 million, or about a 15 – 20% reduction in overall project costs. The process also saved approximately 50,000 tons of raw aggregate and 2,000 tons of asphalt cement. An added benefit of the work in The Pas was the creation of an opportunity for MIT regional staff to observe and review CIREAM first-hand. In consulting with the contractor and witnessing the technical and environmental benefits of the process, the confidence level of these regional staff increased significantly, which helped foster a positive attitude towards using in-place recycling in future jobs. To date the remediated roadway at The Pas is performing well and its solid structural and aesthetic condition is yielding only minimal reflective cracking and smooth ride and surface texture.
Jointly, along with project staff, Mike and Tara reviewed and modified their initial specifications and construction techniques used at The Pas in 2012 and invested capital into essential resources. Major changes included the addition of a third compactor and the equipping of mobile lab units with a full range of testing equipment. These adjustments exemplify dedication to the CIREAM process and continuing product improvement towards process optimization. With their knowledge from 2010, they incorporated these adaptations into the Brandon and Grand Rapids projects in 2012. Through establishing working groups, teamwork, and support from neighboring Ministries, regional staff and contractors, Mike Neil and Tara Liske have helped institute recycling processes into the culture of asphalt remediation in their province.
ARRA 2013 Award for Excellence in Full Depth Reclamation
Paul Ingham Director of Operations, City of Markham, Ontario, Canada
As Director of Operations for the City of Markham, Paul Ingham is responsible for policy development, program planning, fiscal management, administration, and operational direction of the City’s Operations Department. Areas of responsibility include the activities and operations related to roads, parks, forestry, horticulture, storm water system, traffic operations, as well as, fleet procurement and maintenance.
Coordination of the City’s Road Rehabilitation Program resides within the Roads Department which falls under Paul’s direction. Paul recognizes this is an evolving initiative and has encouraged his staff in generating new and innovative approaches within the program and encourages challenges to conventional approaches. He takes personal responsibility for the program to ensure it recognizes triple bottom-line results, Financial, Societal and Environmental.
Through Paul’s guidance, the City of Markham started utilizing FDR with Foamed Asphalt Stabilization in an urban environment in 2002, recognizing the treatment as a more cost effective and environmentally friendly alternative to milling and overlay, being the preferred rehabilitation strategy at the time. Soon after implementing the new technology, Paul was able to recognize other benefits unforeseen during the initial conception stage pertaining to performance. The City quickly realized that cracks were not observed the next spring in the FDR treatment as historically observed in the mill and overlay jobs. In essence, since the existing asphalt was being reclaimed to the full depth, the process removed all deficiencies associated with the aging infrastructure including cracking, rutting, and deformations providing a structurally enhanced, smooth pavement.
Implementing a conventional rural technology into an urban environment presented many challenges that the City staff needed to overcome. Work duration, accessibility for residents and businesses, consistent product quality, and management of the maintenance holes and valve chambers caused the public to often question the approach of the City on many different levels. Paul was able to educate internal management, council, and the public through seminars and public meetings to ensure all stakeholders understood the long-term vision which helped them cope with some of the short-term challenges.
Paul and his team were proactive to rectify these challenges quickly to ensure that they didn’t pose an adverse effect on their planned program. To their credit, the City also works closely with their contractors to ensure that the proper construction methods are exercised to optimize performance and social acceptance. The implementation of the single unit paver-laid recycling train has allowed the City to realize many benefits as historically, a grader laid method was employed where the pavement was pulverized, the access material was removed by a grader and loader, and the resultant pulverized material was stabilized with foamed asphalt. With a single unit train, the recycling operations have been consolidated to obtain benefits such as: increased public accessibility, decrease in construction duration, superior material size and blending, and a consistent compaction across the width of treatment.
To further optimize product quality, the City has mandated the use of Portland cement to increase retained stability and decrease the potential for post-construction raveling caused by weather since 2009. Although this mandate provided a significant increase in product quality, the City experienced many challenges with public vehicles traveling through the cement applied, causing many claims to clean vehicles, and complaints of fugitive dust. Again the City worked closely with the contractors to ensure that gaps between the cement spreader and the recycling train were kept to a minimum to avoid such claims and mandated the use of a spreading device that would minimize dust emissions. In addition, the City has been very active to improve curbside compaction through various compaction methods and auxiliary equipment against curb faces which has eliminated cracking against the curb.
Lowering of maintenance holes and valve chambers within this process initially seemed overwhelming but as both the owner and contractors became more experienced, the process went much smoother. Initially the contractors had many issues with hitting the plates covering the manhole cavity, therefore filling it with pulverized material causing sewer and water main plugs necessitating immediate cleaning and disposal. Paul’s team was able to embrace these challenges through his determination and was able to accept the growing pains of implementing a new process which ultimately led to further growth of the program. Although the quantity of FDR performed by the City varies from year to year depending on budget and scope of work, the average amount of FDR with Foamed Asphalt Stabilization is approximately 82,500 m2 (98,700 yd2) since 2002.
With Paul’s vision, the City of Markham has recognized the need to design the pavements according to the climate, pavement structure, and intended traffic and tracks the performance of strategies to determine the effectiveness of treatments utilized. Through their regimented asset management software, they determine which roads are suitable candidates for rehabilitation by performing pavement evaluations on each road section every two years. Once a pavement falls below a predetermined threshold, the asset management division provides mapping to the Operations department that identifies OCI (Overall Condition Ratings) to each street within the City. The Operations Department then reviews the map and past construction histories and prioritizes them. They have learned through the years that ARRA Award Winners
the software output needs to be confirmed with field evaluations to ensure that the software is predicting pavement performance accurately and ensure they are spending allocated funds appropriately. The City utilizes pre-engineering data and Annual Average Daily Traffic (AADT) volumes to assess the structural capacity of the potential candidates and confirm the feasibility of in-place asphalt recycling. The City then hires a consultant to perform a pavement evaluation and subsequent design considering all of the potential rehabilitation strategies such as FDR with Foamed Asphalt, and mill and overlay, with and without the use of Stress Absorbing Membrane Interlayer.
Markham reports that one of the added benefits of in-place full depth asphalt recycling is the ability to enhance a roadway’s structural capacity or Granular Base Equivalency (GBE), without the need to place additional lifts of hot mix below the wearing course. The placing of additional lifts of hot mix is not only very costly, but may also necessitate the reinstatement of concrete curbs to a higher elevation. The City has successfully employed FDR with Foamed Asphalt Stabilization on community center parking lots, local residential, local collector, and on both two-lane and four-lane major collector roadways with an AADT ranging between 500 – 15.
In 2012, the City performed nearly 40,000 m2 (47850 yd2) of FDR with Foamed Asphalt Stabilization.Prior to performing the in-place recycling process, structures such as maintenance holes, valve chambers, and valve boxes are lowered to sufficient depth to allow the recycling equipment to pass over without interference. Once these adjustments have been made, the area is pre-milled to the depth equivalent to the Hot Mix Overlay depth. Typically the City utilizes 50 mm on residential and collector roadways and up to 90 mm on arterial roadways, all according to the pavement design.
Markham works closely with the contractor to overcome the difficulties often encountered during rehabilitation projects in urban areas where road configurations present challenges in maneuvering the large equipment. The resultant asphalt and underlying aggregates are then reclaimed with the addition of foamed asphalt to a depth of 150 mm and allowed to cure prior to placing the designed Hot Mix Asphalt Overlay.
To quantify the sustainability of treatments utilized by the City, they have hired the University of Waterloo to perform research to provide further information and validate their internal product performance assessments. Furthermore, the City has always been a progressive leader under Paul’s direction in trying new technologies to enable them to decrease life-cycle costs, increase performance, and decrease their environmental impact. Other innovations embraced by the City of Markham include the use of Recycled Asphalt Shingles, Warm Mix Asphalt, Micro Surfacing, and Stress Absorbing Membrane Interlayers. Paul Ingham truly understands the benefits of innovation and is dedicated to raise the bar in pavement preservation implementation in an urban environment.
Paul continues to educate his council on the progress of the pavement maintenance program which is being recognized both internally and externally as a distinguished high rated road network. Paul’s leadership and persistence has enabled the FDR program to continue in the City of Markham where some municipalities tend to revert back to conventional rehabilitation methods when faced with the same degree of adversity. The feats accomplished by Paul to maintain a FDR program are truly unprecedented.