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Use of ASTM A1094 Continuous Galvanized Reinforcement In The Carolina Crossroads Project

Abstract

The Carolina Crossroads project is a state infrastructure design-build project that will cost US$2.08 billion and span several years. It involves renovating 14 miles of I-20, I-26, and I-126, also known as “Malfunction Junction.” This project is part of the South Carolina Department of Transportation’s (SCDOT) 10-Year Plan, which consists of five phases. The first two phases are underway, and the entire corridor is expected to be completed in 2029.

This area sees more than 134,000 vehicles daily. Upon project completion, the average commuter through the I-20/26/126 corridor will save 112 hours each year.

Phase 1 of the project involves redesigning and constructing a new interchange for Colonial Life Boulevard at I-126 and improving I-26 and I-126. The semi-directional interchange concept is being used, which is safer and more efficient.

Phase 2 will update the Broad River Road interchange at I-20 to improve interstate traffic flow and lengthen I-20 westbound access to I-26 westbound to reduce congestion from vehicles changing interstates. To minimize the number of traffic stages and avoid closing existing ramps, an “off-alignment” construction scheme will be used. Given the high congestion level in this area, ensuring the maintenance of traffic during construction was a key focus of the JV’s approach.

Phase 3 involves completing all work necessary to design and reconstruct new interchanges at I-20 with I-26, I-26 with I-126, St. Andrews Road (S-36) with I-26, and Bush River Road (S-273) with I-20. This includes widening the interstate, constructing interchange ramps, collector-distributor roads, crossing routes, frontage roads, side roads, highway bridges, riverine bridges, railroad bridges, retaining walls, noise barrier walls, and related roadway appurtenances in Richland and Lexington Counties.

This paper will only focus on Project ID P03971, which comprises the I-26 to I-20 FUTURE RAMPS, and the construction of the I-26 WB to I-126 EB bridge over the Saluda River and CSX R.R. It’s the largest and most complex bridge on both Phases 1 and 2. This project involves numerous technical details that will be discussed in depth.

Galvanized rebar is now required for all new bridge decks and concrete structures like barriers and sidewalks in Phase 2 of the Carolina Crossroads Project. It was not part of the original RFP for Phase 1 but was later incorporated via a change order. ASTM A767 was referenced, but the JV proposed ASTM A1094 as a substitute due to its resistance to corrosion, low maintenance requirements, and streamlined logistics to provide an equal or better product, and SCDOT approved it.

The procurement portion played a key role in the approval of ASTM A1094, as the ability to have staged rebar ready for fabrication, respond to last-minute changes, and minimize lead times is a big deal on large projects. Also, the A1094 steel is rolled and galvanized at the Mill, the product comes directly from the Mill to the fabricators and can be fabricated like uncoated “black” rebar, which helps expedite deliveries.

Additionally, the availability of mill lengths beyond 60 feet /18+ meter significantly benefits longer bridge projects, reducing the number of splices required.

Conference Paper Details

Session title:
Transportation Structures
Author(s):
Geber, Hans
Sadawi, Ben
Topics:
Structures
Year:
2024