Longhorn Dam Bridge Project | Austin, Texas

Partnership Built on Proven Performance

Jay-Reese Contractors, a specialized construction firm based in Dripping Springs, Texas, focuses on rail, underground, and technically challenging projects. Their deeply rooted partnership with EFCO on difficult rail construction work made them a natural fit for Longhorn Dam’s unique demands.

The project required multiple EFCO formwork systems, including PLATE GIRDER® forms, High-Strength Tension-Compression forms, Round Columns®, and Heavy-duty Bridge Overhang Brackets®. What set this project apart wasn’t just the equipment—it was the months of collaborative design and engineering between Jay-Reese and EFCO that transformed seemingly impossible constraints into workable solutions.

The Challenge: Building Over Water with Extreme Overhangs

For six months, EFCO and Jay-Reese met weekly to develop solutions. Every system had to work within tight vertical clearances between the concrete structure and the water surface. Every support had to function without solid ground below. Every element had to be planned months in advance to coordinate with the beam fabrication and delivery schedules.

Columns, Pier Caps, and Tight Vertical Clearances

One of the first challenges addressed was designing structural spanning forms capable of supporting concrete and working loads while also fitting within the constrained dimensions between the bottom of the cap concrete and the top of the waterline. The team selected the PLATE GIRDER® panel in conjunction with High-strength Tension/Compression forms—compact components specifically designed to fit within the tight spaces without sacrificing structural strength. The EFCO Round Column® formwork system was used as formwork to create the concrete columns, which now serve as vertical supports for the bridge caps throughout the structure.

Balancing Asymmetric Caps with Temporary Counterweights

While most bent caps could be supported conventionally, three caps on this project presented an additional challenge: they were asymmetric. Typically, these caps would require Heavy-Duty shoring to support the imbalanced load; however, working over water meant shoring was not an option. EFCO engineers calculated the exact weight needed and designed temporary concrete blocks that crews would pour next to the permanent structure. These “counterweights” balanced the uneven loads during concrete placement. Once the concrete gained strength, crews removed and discarded the temporary blocks.

Extreme Overhangs and Working Platform Solutions

Beyond the challenges of forming columns and caps, the bridge deck itself presented extreme overhang conditions. In certain areas, the bridge deck overhang extended approximately 14 feet (4.3 m) from the beam centerline–an extreme distance by any standard. Working over water eliminated the ability to use traditional support structures such as shoring. After several design options were presented, it was mutually decided that the safest and most cost-effective route would be to erect a false bent with contractor-supplied driven piles and beams. This false bent served as a secondary support point, allowing EFCO to design a spanning deck that provided support for the CIP slab as well as a safe working area for the crew.

Early Planning: EFCO’s Ganged Overhang Bracket with Web Shoe

It was decided early in the project that EFCO’s Heavy-Duty Ganged Overhang Bracket® with Web Shoe was the right solution, not simply because of the size of the overhangs but also due to the access constraints presented when working over water. EFCO’s Web Shoe anchors directly to the web of the concrete beams using PVC sleeves installed during the fabrication process of the beams. Formwork Erection drawings with insert locations were sent to the beam manufacturer three months before the delivery of beams to the jobsite, and then carefully coordinated with the contractor to ensure accurate placement of the inserts. This early collaboration ensured precise placement and reduced overall costs when beams arrived on-site and were flown into place.

Maximizing Efficiency and Safety

The Heavy-Duty Ganged Overhang Bracket’s unique design further maximized efficiency and safety throughout the construction process. Because the bracket is mounted to the web, the entire gang can be released from inside the beam once the C-Caddy is in place, preventing workers from being under a suspended load. Additionally, any adjustments for elevation of the bridge overhang are made from the deck level, significantly reducing cycle times. This is the only system on the market with these features, making it an ideal solution for this challenging over-water application.

Custom Solutions for Complex Areas

In complex areas between girders–where precast deck panels wouldn’t fit–crews combined SUPER STUD® and DECK STUDS® with Support Brackets mounted on beam webs. This created a complete enclosure that both held the concrete forms and provided safe access for workers, ensuring that every area of the deck could be formed safely and efficiently despite the challenging over-water conditions.