Elemix Polymeric Spheres Reshape Concrete Matrix

In 2008, representatives from tilt-up construction contractors Hi-Tech Tilt of Laredo, Texas, had a fateful meeting with Monaca, Pa.-based Syntheon at

In 2008, representatives from tilt-up construction contractors Hi-Tech Tilt of Laredo, Texas, had a fateful meeting with Monaca, Pa.-based Syntheon at an industry conference. A subsidiary of Nova Chemicals, Syntheon had recently rolled out Elemix, an additive that uses an advanced polymer technology to deliver energy-efficient, durable, lightweight concrete.

Intrigued by the idea of using lighter-weight panels, thus decreasing construction time, Hi-Tech Tilt enlisted Syntheon, whose business focuses on construction technologies and advanced materials fabrication, to use Elemix to produce three test panels for an Ocampo Distribution Center warehouse job in Laredo. Working with local supplier City Ready Mix, Hi-Tech was able to take out all traditional steel reinforcement and use the steel instead as C-Channel studs. The walls were cast on site using about 4 yd. of concrete per panel and remained uncovered for several days while curing.

According to Syntheon, the panels are typically ready after three days with a 500-psi flex strength, but weather delayed the curing process, so the pour-to-place time was one week on this job. Since using Elemix results in a lighter-weight material, the C-Channel studs were all that was required for reinforcement, and it reduced the curing time from seven to three days.

Comprised of specially formulated polymeric spheres dosed at 1-15 lb./yd., Elemix distributes uniformly in concrete mixes for structural and nonstructural applications. With a closed-cell, honeycomb-like interior structure, the additive has the ability to absorb energy, thus reducing cracking and improving thermal efficiency. The spheres allow practitioners to customize lower unit weights, while improving physical characteristics of the mix for better placement and temperature control.

Elemix suits ready mixed and precast concrete. Syntheon officials cite a range of benefits tied to mix designs and finished structures bearing the additive: smaller columns, thinner slabs, and more usable floor space; reduced volume of reinforcing steel and lower foundation costs; lower costs associated with materials, transportation, handling and placement; and, prospective LEED rating points from enhanced R-values and energy savings.

Elemix also made it possible to reduce the amount of large aggregate in the Ocampo project mix design, and made pumping far more efficient. All of the tilt panels are pumped into the forms, explains Luke Kimble, West Coast Business Development representative for Syntheon and Hi-Tech Tilt account manager. The round and soft structure of the raw Elemix makes pumping much easier and more effective. The entire effort had a tight time frame Û from the approval of the mix design to the start of pouring was one week.

Kimble added that one of the most important changes in the way Hi-Tech Tilt constructed this distribution center involved how the wall panels were put into place. The crack-resistant, lightweight panels meant that they could use a 6,000-lb.-capacity Telehandler, rather than a high-capacity crane to move the pieces, he says.

Hi-Tech Tilt was so impressed with the results of using Elemix that the company has already lined up several more jobs in the area using the product. Kimble explained that since the concrete would be covered on one side by insulation and facing on the other, no finish was required on the panels.

The product also can be used in manufacturing block. Benefits include lower unit weights ranging from about 23 to 35 lb.; compressive strength range of 2,120-4,240 psi; improved thermal performance; better texture and consistency; and, less wear and tear on machine and mold parts. Û Elemix/Syntheon Inc.; 412/490-4397; www.elemix.com

ELEMIX CONCRETE ADDITIVE – SUMMARY OF KEY PROJECTS
Application/Project Customer(s) Location Performance Benefit Volume
Manufactured concrete products Lightweight air conditioner pads Camp Logan Houston, Texas Cement Works Ô Lightweight
Ô Durability – crack resistant
400 yd.
Lightweight topping The Peter Lougheed Centre Hospital Burnco Rock Products Calgary, Alberta Ô Lightweight
Ô Pumped well
Ô Durability – crack resistant
Ô Finished well
20 yd.
Elevated concrete floor El Museo Consolidated Carpet New York, N.Y. Ô Lightweight
Ready-mixed University Tech. Milenia Grupo Metal Intra (GMI) Queretaro, Mexico Ô Lightweight
Ô Improved R-value
Ô Durability – crack resistant
Ô Reduced overall cost of structure
Ô Pumped well
400 yd.
Roadwork – road patch Chesterfield City Kienstra Concrete Chesterfield, Mo. Ô Durability – crack resistant 20 yd.
Ready-mixed, finished floor Borella Casino Kienstra Concrete St. Louis, Mo. Ô Lightweight 1,100 yd.