Perfecting the Art of Precast

Coreslab Structures

Precast concrete manufacturing company Coreslab Structures (OKLA) Inc. makes both structural and architectural precast concrete products. Over the course of its history, the company has been recognized many times for the work it does by many of the industry’s leading organizations including the Associated General Contractors of America (AGC), the Associated Builders and Contractors (ABC), Precast Manufacturers of America (PCMA), American Concrete Institute (ACI) and the Precast/Prestressed Concrete Institute (PCI). Last year was the company’s fortieth year as a PCI certified plant. Thirteen of those years date back to the Thomas Concrete years of operation.
Coreslab International purchased Thomas Concrete Products Co. assets back in 1990 and that is when Coreslab Structures (OKLA) Inc. was formed over twenty-seven years ago. Coreslab International owns eighteen plants, mostly located in the southern half of the United States, with the exception of its headquarters located in Hamilton, Ontario, Canada.

Award-winning Coreslab Structures (OKLA) Inc. is committed to offering precast products of the highest quality. Just under a year ago, the company invested in a new state of the art concrete batch plant to replace its older batch plant at the Oklahoma City location.

A batch plant is large-scale, stationary equipment for mixing concrete, and the new plant is capable of batching up to eight yards of concrete in two minutes. This gives Coreslab the ability to batch more cubic yards of concrete per minute than any other concrete manufacturing facility in Oklahoma. This is a significant investment in the future of the company.

The company understands the value of forging strong customer relationships. “We put out a good product, and we’re an ethical company,” says Coleman Harrison, a project consultant with Coreslab. “In the construction industry, you know problems are going to come up, but we’re going to work with the owner, the architects, the engineers and the contractors to get it worked out so that everybody is satisfied.”

The company does a lot of work with repeat clients. Often those clients will come directly to Coreslab to negotiate a job rather than having it publicly bid because they are familiar with the quality of the work and trust the company to do a good job.

Coreslab prefers to get involved in a project early in the design phase so that it can work closely with the architect and the design team to value engineer the job by finding ways to make the build suitable for precast. Precast is a very economical approach, and so by steering the customer toward a precast solution, Coreslab may ultimately save the client substantial amounts of money.

Even when the project is going to be publicly bid, the company will do a lot of pro-bono work up front despite not knowing whether or not it will win the bid in the end. “Half the fight is making sure that the project is precast,” says Harrison. “Whether it’s got to go out to bid or not, it can be pretty daunting for an architect or engineer to start looking at precast if they have no experience with it. Their level of comfort with precast is a significant thing to establish.”

Many of the company’s competitors overlook the value of working with clients in this way. They will wait until the project comes out to bid before investing any time in it, while Coreslab may have been coordinating with the design team for months. This gives confidence to the owners, designers, architects and engineers and helps to build the relationship. The company will help them with understanding specifications and how a project can be tailored to suit precast. It will take them to see current projects to see the mechanics of how everything is put together. All of these things can help with the design.

Coreslab has built precast structures for countless widely varied applications in commercial, industrial, institutional and infrastructure projects. Parking garages are a primary example. The company has worked with many developers to build parking structures for housing units, university campuses, stadiums and more.

Another application with which the company has found a great deal of success is providing precast wall panels for food manufacturing plants. After other trades have constructed foundations and erected steel, Coreslab Structures can surround it with precast concrete panels. This can be done very quickly, leaving the client with a warehouse or manufacturing facility in a very short time.

Data processing facilities are also perfectly suited for concrete precast, and the owners are often drawn to the resilience of the material. The equipment and the data stored within these facilities must be protected from the elements, and precast concrete provides that protection. Wastewater treatment plants, correctional facilities, schools or the wing of a children’s hospital are projects that represent only a small fraction of the company’s portfolio.

Operating in the southern United States has led the company toward another type of project that has become very significant – tornado shelters. Throughout Oklahoma, Arkansas, Kansas and Texas, Coreslab has built dozens of structures that are compliant with the criteria of FEMA and ICC500 – the standards that govern storm shelters. Typically, these are built as above-ground structures doubling as a school gymnasium or something similar, and often have a footprint of around 80×150 feet and thirty to forty feet tall. Coreslab will design the structure to withstand EF5 tornadoes, which is the highest level on the Enhanced Fujita tornado intensity scale, with 250-mile-per-hour winds.

The most recent of these projects consisted of two shelters built at a high school in Moore, Oklahoma which was hit in 2013 with an EF5 tornado causing an estimated two billion dollars damage, causing twenty-four fatalities and injuring 377 others. The work that Coreslab is doing will help to protect thousands of people from future devastation.

One of the pervasive challenges in the construction industry is the continual compression of schedules. “Everyone is on a tighter schedule,” says Sean Morris, engineering manager at Coreslab. “The design team is on a tight schedule to get construction documents out; the construction schedules are more and more compressed; owners are expecting projects to be done in a shorter time period. It’s a constant race against the clock.”

Fortunately, this plays to the company’s advantage as a precaster. One of the key benefits of precast concrete is that it offers the most compact schedule possible for a construction project. If a project’s design is suited to precast, it can be completed very quickly, enabling Coreslab to meet the most stringent time constraints that are often unrealistic for other construction companies.

Precast is an incredibly versatile product. Projects go up quickly and are resilient enough to withstand high-speed winds and tornadoes. Beyond this, precast concrete insulated sandwich panels can also be designed with a high R-value, a measure of how well a material can prevent heat or cold from transferring through it. This means that precast walls can be built in such a way that there is no need for expensive fireproofing or insulation. Projects that would normally require soundproofing are also simplified, as sound does not easily transfer through concrete.

Recently, the company worked with Texas Tech University to test precast concrete panels for debris impact resistance. This test was designed to see how these panels would hold up during a tornado. The company sent four-inch-thick, pre-stressed panels, with prestressed strands as the only reinforcement. Those panels were set up in a laboratory, and sixteen-pound two-by-four boards were propelled at them at one hundred miles per hour. A piece of paper was suspended behind the panels, and the test was said to fail if the paper was perforated in any way.

These tests provided the company with data to show that pre-stressed, precast concrete panels can resist debris impact easily during a tornado event. This happens even at thicknesses as thin as four inches, with minimal reinforcement. The data enabled the company to build sandwich panels, which are two panels sandwiching a layer of insulation, as walls for storm shelters.

This experiment was the first to show the resilience of a four-inch thick prestressed precast concrete wall, and it adds to the already growing list of advantageous properties of the material. Precast is versatile, resilient, strong and offers one of the fastest construction processes available. These things all work together to make precast concrete a choice material for many applications, but beyond function, the product has aesthetic qualities as well.

While many of the company’s competitors focus on either structural or architectural precast, Coreslab Structures (OKLA) Inc. has the expertise in-house to offer both. A project might use precast concrete to add architectural features to a steel-framed structure, or it might build the skeleton out of precast and use other materials for the aesthetic components. Both the structural system and the architectural veneer might be entirely precast. Whatever the approach, Coreslab can build it.

The company has developed a solid reputation as a leader in the precast concrete industry. Coreslab is a precast expert and is committed to helping customers find ways to use the advantages of precast in their projects. “In a nutshell,” says Morris, “it’s versatility, durability, without sacrificing economy, while simultaneously meeting tight schedules.”

More Than Just a Trend

The construction industry is typically slow to evolve. Despite the existence of countless new innovations and technologies, and safer, better ways to do things, it is an industry where tried and true construction methods and long-accepted materials are seldom replaced by a new product or approach.

April 23, 2021, 11:17 AM EDT