Sources: Helix Steel, Ann Arbor, Mich.; CP staff
A proprietary test described in ASTM International’s Journal of Testing and Evaluation provides for direct comparison of steel fiber and conventional rebar concrete specimen tensile properties, according to Helix Steel, developer of Twisted Steel Micro Reinforcement.
The Direct Tension method enables engineers to determine steel fiber specimens’ first crack and post crack tensile strength, plus tensile modulus of elasticity. The testing and data analysis approach greatly reduces the variability of results, Helix officials note, thereby solving past problems rooted in small specimen sizes and material inconsistencies.
“Helix Steel continues to deliver revolutionary and disruptive technologies that offer unprecedented value to the engineering community and concrete industry,” contends Chief Technology Officer Luke Pinkerton. The ASTM-published, peer-reviewed “Measurement of Average Tensile Force for Individual Steel Fiber using New Direct Tension Test,” he adds, further validates the merit of Helix Steel offerings.
The company entered the market nearly two decades ago using as a baseline ASTM C1609 Standard Test Method for Flexural Performance of Fiber-Reinforced Concrete (Using Beam With Third-Point Loading). Recognizing that the market required more relevant information about how Twisted Steel Micro Reinforcement performed in concrete, Pinkerton and the Helix Steel engineering team pursued the Direct Tension testing methodology.