Ultra-High Performance Concrete (UHPC) as defined by the American Concrete Institute (ACI) Concrete Terminology and ACI 239 stipulate calls for meeting a compressive strength between 17,000 psi up to 22,000 psi with specified durability, toughness and tensile requirements provided by the inclusion of fibers. However, because of it’s the materials employed high strength, UHPC can be difficult to create and can become brittle and prone to cracking.
Fortunately, recent UHPC testing and real-world applications by Surface Tech are demonstrating that JUNO XP, the company’s proprietary alternative supplementary cementitious material (ASCM), can provide an “insurance policy” against UHPC brittleness and sub-sequent cracking.
“UHPC has so much cement in it you have to go with a low water mix, and that’s where you run into the possibility of cracking at both early and later stages of the concrete,” said Jon Belkowitz, PhD, Surface Tech’s chief technology officer.
JUNO XP has a mechanical impact on fresh concrete that allows for a reduction of cementitious material, while still maintaining the cream needed to allow grey concrete to flow easily into the formwork. Moreover, JUNO XP has also proven it can increase strength and durability.
“It makes UHPC stronger, tougher and last longer at no additional cost,” said Belkowitz, who added the product is showing spectacular results in current UHPC application testing by one of the nation’s premier concrete precasters.
“JUNO XP is decreasing the binder content by 15 to 25 percent without sacrificing fresh or hardened properties.”
Those who specify and work with UPHC should welcome these results and the fact that JUNO XP is easily adoptable and improves standard, higher performance concrete mixes, in addition to UHPC.
“JUNO XP can be considered a ‘toughening agent’ for UHPC,” said Belkowitz, “meaning it can increase the strain on the concrete before failure, or increase the energy under stress. This positively affects the strain curve as opposed to other supplementary materials, which tends to make the concrete more brittle at high strengths.”
As numerous tests and real-world applications continue to demonstrate that JUNO XP delivers a revolutionary advancement in concrete solutions, it leads Belkowitz to issue his best advice: “Start using Juno XP today! It’s flipping awesome!”