Case Studies for Steelike® UHPC

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Steelike® UHPC Case Studies

UHPC is the answer to concerns about highway infrastructure deterioration, repair and replacement. The remarkable durability of UHPC, supported in part by its resistance to freeze/thaw conditions and its resistance to water and chloride ingress, translates to significantly lower costs over time.

First UHPC Application in U.S. Transportation Infrastructure: Steel Column Repair

Project Owner:  Southeastern PA Transportation Authority (Septa)

Structure:  Walnut Street Tunnel, Philadelphia, PA

Application:  Repair of Steel Columns

Steelike® UHPC is UHPC Powered by Innovation™

Trains pass through the Walnut Street Tunnel about 30 feet under the western end of John F. Kennedy Boulevard on their way to and from Philadelphia’s 30th Street Station.  Prior to the tunnel rehabilitation in 2020, many of the steel columns supporting the roadway above had severe corrosion along their lower portions and the existing concrete encasing the steel base plate assemblies was crumbling.  The Southeast Pennsylvania Transportation Authority (SEPTA) and the Pennsylvania Department of Transportation (PennDOT) specified UHPC to replace the existing 2’-8” tall concrete encasements around the steel base plate assemblies and extended the new UHPC encasements an additional 4 feet to 5 feet above the tops of the original concrete encasements.  The elevated UHPC encasements provide the columns additional compressive capacity and buckling resistance to compensate for severe section loss while also protecting the lower column reaches from any future corrosion.

Steelike® UHPC was selected for the project, which is the first-ever application of UHPC for the repair and protection and steel columns.  More than 50 steel columns were repaired with Steelike® UHPC, with each column requiring approximately 1.5 CY of UHPC.

The choice of Steelike® UHPC for this project gave the contractor several time-saving advantages over competing UHPC products.  Steelike, Inc. representatives worked with the contractor prior to construction to determine an efficient UHPC mixing and placing plan, taking advantage of Steelike’s innovations.

The Steelike® UHPC was mixed in ready-mix trucks parked on the above roadway. With the ability to mix as much as 6 CY of UHPC in a single truck, Steelike was able to provide the contractor with a continuous supply of fresh UHPC with no interruptions.

Furthermore, by mixing in ready-mix trucks, the trucks were able to drive to the opening in the tunnel ceiling  that was nearest to where the UHPC was being placed.  The consistency and ultra-smooth flow of Steelike® UHPC enabled Steelike to adjust the workability of the UHPC to easily flow through the 6-inch diameter tremie hose (with a 4-inch diameter reducer at the end) for placement without any degradation in the mechanical properties – another first for UHPC.  The Steelike® UHPC was discharged directly from a ready-mix truck into a funnel connected to the tremie hose, with the hose directing the UHPC directly into the column forms 30 feet below.  With limited openings in the tunnel ceiling, the tremie hose was sometimes up to 70-feet long, and the Steelike® UHPC easily flowed through it.

Due to some formwork difficulties the contractor had in the tunnel, at one point the UHPC discharging was paused for an extended period with fresh UHPC remaining in the ready-mix truck in 80°F ambient temperatures, Steelike kept the fresh UHPC in the truck alive and workable as long as the contractor needed. More than 1.5 hours passed from when the batch of Steelike® UHPC was mixed to when the last of the batch was successfully discharged and placed, with the ambient temperature consistently above 80°F  the entire time – quite possibly being another first for UHPC!

Steelike™ innovations and the highly refined and 100% preblended nature of Steelike® UHPC made the placement of UHPC a highly efficient operation without any interference or crowding of the construction work taking place inside the tunnel adjacent to an active rail line.  The first-ever repair of steel columns was successfully completed with Steelike® UHPC.

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Innovating How UHPC Overlays are Placed and Cured!

Project Owner: Kane County DOT, IL

Structure: Granart Road Bridge over Big Rock Creek near Big Rock, IL

Application: Bridge Deck Overlay

Steelike® UHPC is UHPC Powered by Innovation™

The Kane County Division of Transportation specified UHPC to rehabilitate the deck of the Granart Road Bridge spanning Welch Creek near the town Big Rock in the summer of 2020. The deck is approximately 142-feet long and 50-feet wide. In order to keep traffic flowing and also to accommodate the contractor’s equipment, the contractor chose to place the overlay in three stages each approximately 17-feet wide.

Each stage of overlay placement required approximately 11 cubic yards of UHPC. Steelike mixed the UHPC in two standard front-loading ready-mix trucks, providing a steady supply of fresh UHPC with no time wasted waiting for UHPC to be mixed. Additional time savings were had by driving the ready-mix truck up to the placement areas and directly discharging the UHPC from the truck to the deck surface. This also saved significant amounts of UHPC waste by not having to transfer the UHPC to buggies.

As the overlay was placed, the contractor completely covered the fresh UHPC with a curing compound specified by Steelike. One unique behavior of Steelike® UHPC is that the skin it forms when curing is extremely resistant to cracking and it prevents moisture loss. This behavior combined with a thorough covering of a specific curing compound enabled the contractor to cure the overlay without plastic sheeting. Not using plastic sheeting eliminates the risk of the sheeting leaving marks or impressions in the overlay surface, the risk of workers stepping on the soft overlay surface while placing or adjusting the plastic sheeting, the risk of wind blowing under the sheeting rendering it ineffective at preventing moisture loss, and the risk of wind blowing the plastic sheeting into live traffic in the adjacent lanes. Finally, it eliminates a construction step and saves the contractor time and money.

After the overlay was cured, the overlay surface was grinded and grooved to provide the final crack-free riding surface. Steelike™ innovations made the overlay placement more efficient than traditional UHPC overlay operations, saving the contractor time and money.

Steelike™ Innovation Supports Off-Site Mixing and Driving to the Project Site for the Repair of Longitudinal Precast Beam Connections

Project Owner: Kane County DOT, IL

Structure: Hughes Road Bridge over Blackberry Creek in Elburn, IL

Application: Repair of Longitudinal Joints between Precast Beams

Steelike® UHPC is UHPC Powered by Innovation™

The Kane County Division of Transportation needed to repair the longitudinal joints between the existing precast beams on the Hughes Road Bridge over Blackberry Creek. The joints consisted of narrow grouted shear keys, and the grout had failed, allowing differential movement between the beams and causing the existing concrete overlay to crack and deteriorate. The decision was made to repair the joints with UHPC.

To carry out the repair, after removing the concrete overlay, the joints were widened to expose the top corners of the steel reinforcing bar stirrups in the beams. The stirrups were connected across the joints with new steel reinforcing bar ties, then Steelike® UHPC was poured into the joints. The Steelike® UHPC enveloped the exposed stirrups and the tie bars, making the transverse reinforcing bars continuous across the width of the deck. Combined with the high compressive strength, strong bond strength, and extreme durability of UHPC, the new Steelike® UHPC connections will stay crack-free and prevent differential movement of the beams for many decades or more, preventing cracking and premature deterioration of the new asphalt overlay.

Supporting the contractor’s needs, the Steelike® UHPC was mixed off-site in a standard front-loading ready-mix truck and then driven to the project site for discharge. The total time from mixing to complete discharge, the Steelike® UHPC was kept alive and workable for nearly 1.5 hours. This added convenience for the contractor and also provided a continuous flow of fresh UHPC due to the large volume of the ready-mix truck.
The forming and curing of the UHPC connections following conventional UHPC practices, whereby the connection were overfilled by 0.25 inch and top formed. After the UHPC cured and the top forms were removed, the contractor observed that there were no air bubbles in the tops of the connections. With a lack of air bubbles and the fact that the repaired bridge was getting an asphalt overlay, the contractor was allowed to skip grinding the connections, saving time and money.

Steelike™ innovation supported the contractor by facilitating off-site mixing and providing a continuous flow of fresh UHPC to save the contractor time and money.

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Steelike™ Innovation Accelerates the Repair of Longitudinal Precast Beam Connections

Project Owner: Kane County DOT, IL

Structure: Scott Road Bridge over Welch Creek near Big Rock IL

Application: Repair of Longitudinal Joints between Precast Beams

Steelike® UHPC is UHPC Powered by Innovation™

The Kane County Division of Transportation needed to repair the longitudinal joints between the existing precast beams on the Scott Road Bridge over Welch Creek. The joints consisted of narrow grouted shear keys, and the grout had failed, allowing differential movement between the beams and causing the existing concrete overlay to crack and deteriorate. The decision was made to repair the joints with UHPC.

To carry out the repair, after removing the concrete overlay, the joints were widened to expose the top corners of the steel reinforcing bar stirrups in the beams. The stirrups were connected across the joints with new steel reinforcing bar ties, then Steelike® UHPC was poured into the joints. The Steelike® UHPC enveloped the exposed stirrups and the tie bars, making the transverse reinforcing bars continuous across the width of the deck. Combined with the high compressive strength, strong bond strength, and extreme durability of UHPC, the new Steelike® UHPC connections will stay crack-free and prevent differential movement of the beams for many decades or more, preventing cracking and premature deterioration of the new asphalt overlay.

Steelike™ innovations were used to accelerate the construction and lower the contractor’s costs. The Steelike® UHPC was mixed in ready-mix trucks, providing the contractor with a continuous flow of fresh UHPC with no delays. Whereas deck-level connection are typically overfilled and top formed, the UHPC connections were cast flush along one edge and only raised on the lower edge as needed due to the large superelevation.

Furthermore, no top forms were used. Steelike’s innovative placement procedures facilitate flush forming and no top forming. With no air trapped by a top form, there was no air-filled layer that needed to be grinded off. With an asphalt overlay being placed on top, the contractor was able to complete eliminate grinding.

Once the Steelike® UHPC connections had fully cured, the asphalt was placed on top, and then the bridge was opened to traffic.
Steelike™ innovation supported the contractor by providing a continuous flow of fresh UHPC, eliminating top forming, pouring the connections flush to the deck on one side, and eliminating grinding, saving both time and money.

Steelike™ Innovation Eliminates Top Forming, Overfilling, and Grinding for Deck Panel Connections and Expansion Joint Header Repairs

Project Owner: West Virginia Parkways Authority

Structure:  Bridge 3020S – SB – Milepost 30.62 (BDR-3-20), W VA

Application: Closure Pours between Precast Deck Panels and Haunches and Shear Pockets; Expansion Joint Headers

Steelike® UHPC is UHPC Powered by Innovation™

The West Virginia Parkways Authority needed to replace the decks of two bridges on Interstate 77 near Shady Spring, WV. In order minimize traffic disruptions, the Authority chose to construct the new bridge decks with precast concrete deck panels. To maximize the durability of the new decks and make sure the connections are strong and long lasting, they chose to use UHPC for the connections, as well as the deck panel haunches and shear pockets. The Authority also specified UHPC for the repair of the expansion joint headers. The existing steel header angles and the supporting concrete blocks were to be completely removed and replaced with UHPC. The strength and durability of UHPC allow it to serve as expansion joint headers without the need for steel angles to reinforce the corners.

The contractor chose Steelike® UHPC for the project, because of all the Steelike™ innovation that help the contractor save time and cost. The Steelike® UHPC was mixed in ready-mix trucks in order to provide a continuous supply of fresh UHPC without interruptions. To save time on the UHPC placement days, the ready-mix trucks were preloaded with the Steelike® UHPC dry mix the day before, enabling the trucks to discharge fully mixed Steelike® UHPC in under 30 minutes.

Additional innovations were implemented during the UHPC placement, allowing the deck panel connections to be cast flush with the deck without trapping air under the top forms. The expansion joint headers were also cast flush with the deck. This allowed grinding to be completely eliminated from the project.

Steelike™ innovation supported the contractor by providing a continuous flow of fresh UHPC, eliminating top forming, pouring the connections and the expansion joint headers flush with deck, and eliminating grinding, saving both time and money.

Powered by Innovation™: Steelike™ Innovations Eliminated Plastic Sheeting on One of the First UHPC Overlays on a Long-Span Suspension Bridge

Project Owner: Rhode Island Turnpike and Bridge Authority (RITBA) and Kane County DOT, IL

Structure: Claiborne Pell Newport Bridge, Newport, RI

Application: Bridge Deck Overlay

Steelike® UHPC is UHPC Powered by Innovation™

The Rhode Island Turnpike and Bridge Authority (RITBA) has been undertaking a decades-long process of rehabilitation the deck of the Claiborne Pell Newport Bridge and its approach spans. The Authority has performed partial-depth deck replacements on the approaches using conventional high-performance concrete. The existing concrete is removed to about one inch below the top reinforcing bar mat. Using hydrodemolition for removal is an effective way to remove concrete and provide a fracture-free substrate surface for the overlay, but the reinforcing bar mat shields the concrete under the bars, which leads to extensive manual labor to remove.

In 2020, the RITBA decided to consider UHPC for the suspension span deck, applied as a thin overlay above the top reinforcing bar mat. The enhanced durability and bond strength of UHPC is expected to allow a thin UHPC overlay to perform as well as, if not better than a partial-depth deck replacement with conventional concrete. Therefore the RITBA commissioned a UHPC overlay pilot project. Steelike® UHPC was selected to participate in the pilot project for a 10-feet wide by 90-feet long placement on the main span.

Several Steelike™ innovations were employed on the Newport Pell Bridge. The Steelike® UHPC was mixed in two standard front-loading ready-mix trucks off the bridge in a staging area, eliminating the congestion and setup time required to install immobile mixers on the bridge deck. Once a truck was ready to discharge, it was driven on to the bridge. This provided a continuous supply of fresh UHPC.

As the overlay was placed, the contractor completely covered the fresh UHPC with a curing compound specified by Steelike. One unique behavior of Steelike® UHPC is that the skin it forms when curing is extremely resistant to cracking and it prevents moisture loss. This behavior combined with a thorough covering of a specific curing compound enabled the contractor to cure the overlay without plastic sheeting. Not using plastic sheeting eliminates the risk of the sheeting leaving marks or impressions in the overlay surface, the risk of workers stepping on the soft overlay surface while placing or adjusting the plastic sheeting, the risk of wind blowing under the sheeting rendering it ineffective at preventing moisture loss, and the risk of wind blowing the plastic sheeting into live traffic in the adjacent lanes. Finally, it eliminates a construction step and saves the contractor time and money.

After the overlay was cured, the overlay surface was grinded to provide the final crack-free riding surface. Steelike™ innovations made the overlay placement more efficient than traditional UHPC overlay operations, saving the contractor time and money.

Empowering Research for New UHPC Design Guidelines

Project: FHWA, Turner-Fairbank Highway Research Center; UHPC pouring in Allentown, NJ

Application: Precast, Prestressed UHPC Girders

Steelike® UHPC is UHPC Powered by Innovation™

In 2019, the Turner-Fairbank Highway Research Center of the Federal Highway Administration (FHWA) selected Steelike® UHPC for the casting of multiple full-size precast prestressed UHPC bridge girders to be used as test specimens.

Because Steelike® UHPC can be reliably mixed in standard ready-mix trucks, large quantity batches of UHPC were prepared with ease, providing a constant flow of fresh UHPC to fill the large girder forms.

After casting and curing, the girders were transported to the FHWA laboratory. The girders are being tested by FHWA to better understand how structural UHPC girders behave in order to develop UHPC structural design guidance for the United States.

The selection of Steelike by the FHWA is proof positive that Steelike® UHPC meets or exceeds the mechanical and durability requirements established by the federal government for UHPC. Thanks to Steelike® UHPC and the FHWA, the United States will soon have UHPC structural design guidance to help the engineering community reduce maintenance needs, extend the life of the nation’s infrastructure, and design more efficient structures that use up to 40% less material than conventional concrete.

Helping to Protect Our Nation’s Heroes

Project: US Department of Defense UHPC Research Program, Fort Knox, KY

Application: Security and Defense

Steelike® UHPC is UHPC Powered by Innovation™

Beginning in early 2016, in support of a Department of Defense, Research and Development Program, Steelike® UHPC was used as part of a UHPC research program. Steelike® UHPC was used at the Rodgers Hollow Test Site in Fort Knox, KY, under the direction, instructions, and supervisions of the Facility Engineer / Manager.

Steelike® UHPC was mixed in locally available standard front loading ready-mix trucks, and the strength of the Steelike® UHPC consistently exceeded the program UHPC strength requirements.

By the end of the program, approximately a quarter of a million pounds of Steelike® UHPC was provided supporting over 200 cubic yards of placements. Each batch was monitored closely for quality control and test cylinders were taken for each batch to verify strengths. All batches exceeded the required minimum UHPC strength.

Steelike® UHPC exceeds the requirements of the US Department of Defense and is proud to play a role protecting our nation’s military.

When Your Project Calls for UHPC, Call Steelike® UHPC.

Attributions for Graphics Used on This Page:

Icons made by Freepik from www.flaticon.com | Icons made by Smashicons from www.flaticon.com

Image: Claiborne Pell Newport Bridge – Rhode Island Turnpike and Bridge Authority (RITBA)

Image Source: Combined Military Service Digital Photographic Files