How Reusing Existing Pavement Materials Improved New England's Only Deep-Water Container Terminal

Abstract: Massport’s Paul W. Conley Container Terminal, in Boston Massachusetts, is a vital economic asset for New England, serving more than 2,500 regional businesses. As New England’s only deep-water, full-service container terminal, this 101-acre facility accommodates an average of four to five vessels per week. To maintain its competitiveness, Massport launched the Conley Terminal Modernization Program in 2014, an $850 million investment in the Port of Boston’s maritime infrastructure. One of the key projects of the program was the rehabilitation of the backland container area behind Berths 11 and 12. As the most utilized area within the busy terminal, this area serves as interim storage for thousands of shipping containers after being unloaded from vessels and prior to being loaded onto trucks for delivery to the consumers throughout the region.
Originally constructed in the 1980’s, decades of heavy industrial use have resulted in degradation of the pavement and drainage infrastructure resulting in sinkholes, differential settlement of pavements and concrete crane runways, and water ponding and freezing in winter causing unsafe and inefficient operating conditions for personnel and cargo-handling equipment.
The Conley Terminal Berth 11 & 12 Backlands Reconstruction Project utilized an innovative and sustainable approach to address these issues including a full-depth pavement reclamation and recycling process to reuse existing pavement and subbase materials. This approach reduced waste material, construction costs and operational downtime by eliminating off-site disposal of the existing asphalt and the need to import new subbase materials to the site. This approach had not been used previously in the U.S. Northeast and had only been used twice in North America. This was the first time it was applied on existing pavement 24” deep, which was known to be present at the site.
The reclamation process included grinding the existing pavement and subbase materials, which were then reutilized as the new subbase. Technical Solutions (PTS) assisted the design team with the assessment of the existing pavements in the container yard by utilizing non-destructive testing (NDT). The NDT data collected by PTS was analyzed to assess the strength characteristics of the pavement layers and subgrade to determine depth of reclamation required. In addition to this testing, 18 test pits were dug around the site to evaluate subsurface conditions and to support the pavement design.
This project met Massport’s primary Condition of Satisfaction of completing the project on time and under budget without interrupting Maritime Operations. In addition to meeting the client’s other Conditions of Satisfaction, including minimizing environmental impacts, improving the efficiency of stormwater management, maintaining safety and security, and verifying the satisfaction of regulatory authorities, stakeholders and Maritime Operations, the efficiencies realized with the innovative method resulted in a construction cost savings of $1.5 million (approximately 18% of total construction costs). The Conley Terminal project produced a durable pavement product that is standing up to the heavy industrial traffic of a container port while utilizing sustainable principles to reduce energy consumption as well as waste through the innovative re-use of existing pavement materials.

How does this project / topic contribute to the advancement of the industry and profession?: The use of this innovative pavement recycling method at Conley Terminal in Boston Massachusetts will provide justification that this method is viable for reconstruction of heavy-duty pavements at container storage yards in cold climates. It will be used as a basis for how improvements can be completed at an active marine terminal with no interruptions to operations and with reduced carbon emissions during construction by reducing the amount of truck hauling required.

Does the project / topic implement new and innovative techniques, materials, technologies, and delivery methods?: The Conley Terminal Berth 11 & 12 Backlands Reconstruction Project utilized an innovative pavement recycling method not previously utilized in maritime construction in the Northeastern United States and only previously used twice in North America. Utilizing a combination of non-destructive testing and specifically placed test pits, the design team was able to review and analyze existing conditions to help in the proposed pavement design. The method also provided a cost-effective solution that enabled a greater area of reconstruction to be performed with limited available funds.

What was the most challenging aspect of your project / topic and how did you handle it to ensure success?: As a vital economic asset for New England and as the only deep-water, full-service container terminal, it was important to maintain operations at Conley Terminal during construction. With four to five vessels a week unloading thousands of containers for truck hauling around the northeast and beyond, it was essential that coordination be maintained between the contractor and the maritime operations staff to maintain constant access through the terminal for the large gantry cranes unloading the vessels and for the hundreds of trucks entering and leaving the terminal each day.

Who is the target audience for this paper?: Seaport engineers, civil site engineers, transportation engineers, marine terminal owners, operators, labor, and policy- and decision-makers will benefit from an understanding of our project and lessons learned. The presenter is a transportation engineer with almost two decades of experience with roadway and pavement lot design and stormwater analysis and design.