Harco Street, et al.
Location
Woodruff Avenue to Conquista Avenue
City or County Responsible for Project
Los Angeles County
Category
Roads: Efficient and Sustainable Road Maintenance, Construction and Reconstruction Projects.
Author
Greg Kelley
Los Angeles County Public Works
900 South Fremont Avenue, Alhambra, CA 91803
6264584911
Project Description
Los Angeles County Public Works has utilized sustainable pavement treatments with remarkable success since 2008. We continue our commitment to preserving and improving the quality of our roads in a cost effective and environmentally responsible way. The state mandate (AB32) to reduce greenhouse gas (GHG) emissions and limited budgets were key motivators for developing our sustainable approach that emphasized (1) focusing on preserving roads in good condition first; (2) using recycled materials in pavement treatments; and (3) reutilizing materials in-place when reconstructing our roads. The Harco project, completed in November 2019, showcases the benefits when properly applying this approach. The project covers 7 lane miles (545,000 feet²) of local roads in the unincorporated community of Long Beach Islands. The pavement had a poor condition rating and exhibited heavy distresses and localized base failure. Reconstruction of the roads was considered as the best solution. Traditional reconstruction method of removing and replacing the existing road materials was estimated to cost $3.5 million. The proposed sustainable reconstruction approach of reutilizing the in-place materials was estimated to save $1.0 million and achieved significant environmental benefits. The project scope included importing 3” of the reclaimed asphalt pavement for use in the Cold Central Plant Recycling (CCPR) process; cement stabilizing the existing asphalt pavement (AC), base, and subgrade; placing the imported 3” CCPR AC on the cement stabilized base material; and constructing 1½” of Asphalt Rubber Hot Mix (ARHM) as wearing surface. This method required less construction workdays and mitigating traffic impacts. Environmental benefits included reduction in GHG emissions by 89%, in energy usage by 88%, and landfill by 15,300 yards³. The ARHM resulted in 14,200 scrap tires being diverted from landfill. The cost savings of $1.0 million was reinvested to improve other County roads. The project was delivered utilizing the Job Order Contracting (JOC) along with support from own forces to perform the concrete parkway improvements. The JOC process is a flexible unit price contracting method used to complete maintenance, repair, and refurbishment of County roadway infrastructure and building facilities. This was our first time using JOC for this type of road reconstruction as we continue to explore innovative ways to deliver projects more efficiently. In summary, the Harco project improved the overall quality of the County’s road network in a cost effective and environmentally friendly way. The County’s sustainable approach is a straightforward formula for addressing the issues of limited funding and reducing GHG in a practical manner, while providing direct benefits to our constituents. The use of JOC also allowed us to deliver the project in an accelerated yet efficient manner. We welcome opportunities to share our experiences and collaborate with other local agencies.
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