Our innovative cast-in-place precast alternative showcases the adaptability and benefits of precast concrete pavement technology for high-traffic applications.

Project Details

• Owner: Alabama DOT
• Contractor: McElhenney Construction Company LLC
• Precaster: Universal Precast, Inc
• Project Completion: 2017
• Scope: 65 slabs

Project Overview

This project, located on a heavily trafficked truck route leading to the Port of Mobile, AL, showcased the efficiency and adaptability of Super-Slab® as a cast-in-place alternative. 

A critical aspect of the project was the execution timeline. 

Given the high traffic volume, a complete shutdown was not feasible. Therefore, the project emphasized minimizing disruptions by conducting major installations overnight, allowing the road to remain operational during peak hours. 

This approach highlighted Super-Slab®’s quick setup and robust immediate-use capabilities.

This was especially relevant due to the project’s nature as a demonstration for the Strategic Highway Research Program (SHRP2) program.

The program, which consisted of more than 100 research projects designed to address critical state and local challenges, such as aging infrastructure, congestion, and safety, has introduced dozens of products, procedures, and other innovative practices to DOTs and municipalities nationwide.

As an innovative cast-in-place precast alternative, Super-Slab® is one of those critical products. 

Scope and Details 

Rutting caused by heavy truck traffic along a major corridor in Mobile, Alabama provoked rehabilitation of the distressed asphalt concrete ramp at Exit 2 of I-165.

In the past, the Alabama DOT repaired the rutting using the mill and fill technique, including heater scarification (hot in-place recycling). However, rutting up to about 4 inches deep reappeared within a few months, requiring frequent maintenance operations along the left turn lanes.

The DOT had considered traditional concrete pavement for the rehabilitation but was concerned about the required extended lane closure. The SHRP2 made it possible for the DOT to explore precast concrete panels for this project instead, and the contractor chose Fort Miller’s Super-Slab® product to meet the specifications.

The area chosen for repair was two lanes wide, and the plans called for a single slab to span the full width, eliminating an open longitudinal joint between the two lanes.

The project utilized Fort Miller’s innovative “Crack Inducer Detail,” a design feature that strategically induces a controlled crack at the center of the slabs to enhance durability and performance. 

Additionally, Fort Miller’s FM Lifters were essential for accurately jacking the slabs vertically into position, ensuring a precise fit with a specified minimum of ½-inch of bedding grout beneath each slab. 

This meticulous approach not only maintained the integrity of the road surface but also extended its lifespan, reducing future maintenance needs.

A three-lane closure was established during the nightly installation work, which allowed one lane along the ramp to be open to traffic exiting at Exit 2. 

Impact and Innovation 

The project successfully implemented durable repairs within constrained overnight windows, reducing future maintenance needs and demonstrating Super-Slab’s suitability as a cast-in-place precast alternative for high-traffic areas.

Despite challenges, including interruptions from Hurricane Irma which caused flooding and detours, construction was able to promptly resume post-emergency. 

This resilience underscores the benefits of precast concrete pavement technology, as noted by the Alabama DOT—the ability to halt and restart projects with minimal disruption to the public.

The ramp rehabilitation project was the first application of the precast slab technology by the DOT, and they plan to use the technology in future pavement repair and rehabilitation projects.

Partnership and Nationwide Influence:

Fort Miller not only provided the technology but also engaged closely throughout the project, offering engineering, formwork, and field support. 

Committed to safer, faster, and more reliable highway construction nationwide, Fort Miller extends this technology through partnerships and licensing agreements with other precasters, enabling broader dissemination beyond direct shipping capabilities. 

By successfully implementing these repairs within the constraints of limited overnight windows, the project underscored Super-Slab®’s role as an efficient cast-in-place precast alternative, capable of meeting rigorous demands with minimal traffic interference.