Along with accepting new test methods, producers are discovering other methods to overcome the obstacles of self-consolidating concrete (SCC) acceptance. One new approach of proportioning concrete and reducing cement content has been developed by iCrete.
SCC mixes proportioned using the iCrete technology have all the attributes of SCC at less material cost and with more robustness. This means producers will batch the same concrete every time regardless of slight variations in the ingredients.
A robust and cost-effective SCC mix is one a contractor will opt to use. The iCrete technology is a method of proportioning concrete based on proprietary algorithms and tight control of the raw materials, especially aggregate moisture.
“Every mix design engineer has a unique characterization technique for the raw materials used to meet a certain strength requirement,” says Jack Holley, iCrete's director of concrete development. “But ours is a little different. We are not necessarily going for maximum particle packing, but for optimum particle packing. The result is a mix matrix that is very stable and that allows the producer to batch a mix with SCC properties a lot easier and to do it in a repeatable way.”
Mix designs using iCrete will almost always be specified as performance-based. “We will work within the parameters of what the industry and the particular job requires,” says Holley. “But we will try to challenge any prescriptive requirements, like water-cement ratio or minimum cement content, to move toward the performance the contractor and designer are really looking for, whether it's SCC properties, modulus of elasticity, pumpability, or low shrinkage and creep.”
Atlantic County Concrete is supplying SCC to the Revel project in Atlantic City and has switched completely to the iCrete system for its mix design. “Our iCrete mix is more consistent than our commercial mix, and we are able to do it with a better blend of materials,” says Atlantic's project manager, Bob Todd. “We've also been able to meet the performance specification and reduce our material costs.”
What's most unique about iCrete is that producers are easily able to produce robust SCC mixes with precision properties that stay within tolerance, without increasing the production and materials costs.
Working with the producer's existing raw materials, iCrete is able to produce mixes to meet any performance need. “Usually the producer doesn't need to add new materials that would require new aggregate bins or silos,” says Holley. “We're not asking for a higher cementitious fraction that's going to drive the cost up ridiculously. And we will provide an even more consistent product so the producer doesn't have to worry about batch-to-batch variations and segregation without using lots of filler and high dosages of viscosity modifiers.”
For more, visit www.icrete.com.