Today’s concrete technologies provide exciting new capabilities for designers, engineers, builders and producers. Sophisticated chemical admixtures, a range of cementitious materials with varying properties, and newer fibers of plastic and steel can be creatively combined to develop stronger, more durable concrete that is easier to place and finish.

Prairie’s commitment to concrete innovation has led to establishing a new concrete lab at Yard 9 in Melrose Park, IL about 12 miles west of Chicago’s Loop. The lab is designed to leverage the experience gained on recent projects like Trump Tower to develop new “value-added” mixes for the construction industry.  “With the products on the market today we can help builders meet their requirements for workability and speed while meeting or exceeding the strength, structural and aesthetic requirements specified by the engineers and architects,” says Jack Gibbons, Prairie’s Director of Technical Services.  “We believe Yard 9 will help us to move the market toward performance concrete - not just for the high profile jobs, but to solve persistent challenges in 3000 and 4000 psi structures.”

Creating a performance mix design is a careful process. Starting with the architectural and engineering requirements listed in a spec sheet and input from the builder/contractor, our designers propose a mix design that addresses the design/build requirements, the schedule and the budget. This design may include partial replacement of Portland cement with fly ash or slag, supplemental admixtures for specific strength, place ability, or finishing characteristics, and particular gradations of aggregate. To test the design concept, we bring the materials to the Yard 9 lab, carefully weigh each element and then mix them in the six-cubic foot lab mixer. We test the resulting mix for any of the following combinations: entrained air; slump; temperature; unit weight; consistency; finish ability; set time; total heat output; compressive and flexural strength; shrinkage; permeability; chloride ion penetration; hardened air content; freeze-thaw; salt scaling resistance; and modulus of elasticity.

If the test batch results are acceptable, we take the design to the ready-mix yard that will be shipping the concrete to the job. The mix design is now weighed up in a three cubic yard test batch, loaded into a truck and retested. This testing is performed by an independent credited lab to verify the results determined at the concrete lab. The results from the credited lab are reviewed and sent with the mix design to the contractor for approval by the architect or engineer on the project. The whole process can get expensive - testing for some mix designs can cost $8,000 – 10,000 before one yard is sent to the jobsite.

 Prairie is also using Yard 9 to conduct more general research and development such as refining concrete concepts like pervious concrete, improving mix designs for specialty applications like warehouse floors, and evaluating the different products coming into the market place like chemical admixtures, fibers and cementitious materials.

Yard 9 complements Prairie’s outstanding Bridgeview lab where it conducts forensic and troubleshooting microscopic analysis. “At Bridgeview the focus is on learning about the interactions of the materials at a microscopic level. At Yard 9 it’s all about determining what characteristics we can develop in the mix that will create a product that is more beneficial to our customers in the field,” says Gibbons.

Yard 9 is also used as an educational center for Prairie’s Quality Control Technicians. “Our technicians come here to work with the various new products and mixes to get an understanding of the material before they have to work with it in the ready mix yards,” says Theron Tobolski, Prairie’s Special Projects Coordinator. Occasionally, speakers from different aspects of the concrete industry come to present new products or concepts as well. “We believe that this lab is not only valuable to Prairie’s Technical team but to our customers as well,” says Tobolski.