Owners, designers and builders have come to rely on Prairie Material for innovative and reliable ready-mix designs. Today, most major construction projects use more than 10 separate mix designs for various aspects of the job. In fact, Prairie developed more than 20 mixes for Chicago's Trump Tower, from 16,000 psi high performance concrete at the setbacks to low-heat 10,000 psi SCC in the 10-foot deep foundation pour.
Our experienced concrete professionals in the Technical Services Group work with the engineers and architects to review the design specifications while partnering with the contractor and builders to develop mixes that ensure good workability, improved construction schedules and high finished quality. The overall result is better in-place performance.
Our approach is collaborative and iterative. With our extensive testing program, first-class lab and rigorous quality control, Prairie is constantly improving our mixes and product offerings to satisfy any design or construction requirement. During construction we continue to tweak the mix for the variability of weather and season to keep the job going no matter what. Prairie has helped our building partners to meet some of the most aggressive schedules in the industry, providing the concrete they need with precision load after load, day after day.
Although our custom mixes are designed to meet for very specific applications, many of them fall into the following categories:
High Performance Concrete
High Performance Concrete (HPC) refers to concrete with a specified compressive strength of 6,000 psi and greater. In fact, Prairie has delivered 16,000 psi concrete and is capable of supplying concrete at greater than 20,000 psi. Prairie has also designed and delivered HPC in high flow and self-consolidating formulations for many projects.
Prairie's HPC mixes have been used for high rise buildings in Chicago like Trump Tower
, to meet the structural needs of Miller Park in Milwaukee and to provide 100-year concrete for Wacker Drive. By carrying loads more efficiently than normal-strength concrete, high-strength concrete can reduce the total amount of material placed and lowers the overall cost of the structure.
Flowing and Self Consolidating Concrete
SCC in Action
See how Prairie's Self Consolidating Concrete was able to literally turn a corner at the Discovery World aquarium pour.
Self Consolidating Concrete (SCC) is a highly workable concrete mixture that can be placed in restricted structural elements compacting by means of its own weight without vibration. Prairie's SCC mixes use a system of optimized aggregates, cements and admixtures including a "super-plasticizer" which keeps the mix very fluid during the pouring process without aggregate separation or compromising the material's ultimate strength.
Prairie has designed SCC for pours involving unusually dense reinforcing steel such as Trump Tower's
mat foundation and upper level outrigger floors, as well as the main aquarium structure for Milwaukee's Discovery World. Prairie has also developed flowing mixes with high slumps for rehabilitation projects at the Lockport Lock and Dam complex as well as the precast arches for the I-88 bridge over the Fox River.
Structural Lightweight Concrete
Lightweight concrete for structural applications has a density of 90-115 lb/ft³ compared to normal weight concrete of 140 - 150 lb/ft³. Made with special lightweight coarse and fine aggregates and air-entrained, structural lightweight concrete provides a better fire rating and a higher R value which offers better insulating qualities for wall elements. Prairie has designed lightweight concrete mixes with the same strengths as normal weight concrete.
Typically, lightweight concrete is used to reduce the dead load of a concrete structure, which allows the structural designer to reduce the size of columns, footings and other load bearing elements. This reduces the need for steel reinforcement and lowers the volume of concrete, which lowers overall costs.
Lightweight concrete can be tricky to use since lightweight aggregates absorb more moisture than other aggregates. Prairie recently designed a lightweight mix for the 60-story Chicago high-rise at 300 N. LaSalle that not only solved this problem but could be pumped through normal slick lines up more than 600 feet vertically and 50 feet laterally.
Prairie has designed lightweight structural concrete for piers and beams, slabs and wall elements in steel and concrete frame buildings of all sizes, parking structures, tilt up walls, topping slabs and composite slabs on top of metal decks.