Technical
Click Here for the Helix Dosage Calculator.
Click Here for the Helix ICC Report. You can also visit the ICC website - www.icc-es.org - and search their evaluation reports for Helix or report number ESR-3441.
A simple idea hatched from examining the difference between a screw and a nail has allowed Helix to offer the construction industry unprecedented performance and economy. What was not possible before, complete rebar replacement, is possible with Helix.
The performance of standard concrete reinforcement is governed by friction. Concrete must crack and the rebar begin to slip before it can engage and carry any load. Rebar is deformed to increase the friction between the rebar and concrete to reduce slippage once it starts.
Helix, on the other hand cannot slip out of the concrete. It must untwist. The video below shows Helix actually untwisting as it's pulled out of a block of concrete.
Untwisting requires six times the amount of force as a smooth steel bar to pull out of concrete AND it holds on with the same amount of force regardless of how far it's pulled out. The tensile resistance Helix provides is large and constant enough to allow for the replacement of rebar even in structural concrete (not just slabs on grade).
Helix is designed using a method proven in the field over a ten-year period that uses the same principles used for standard rebar design. Our ICC approved and third party reviewed design methods make it easy for engineers. Its as simple as computing the required standard rebar using normal methods and then applying a table to convert the required area of steel to a Helix dosage. The table is developed using ASTM E111 (the same test used to measure rebar tensile properties) compliant direct tension testing of bars of Helix reinforced concrete. Click here (link to contact page) to obtain a copy of the peer reviewed Helix design criteria and commentary.
Applications for Helix include, but are not limited to: structural foundations, footings, slabs, walls, shot-crete and precast products. Helix has been used in commercial buildings, residential, airports, paving/bridges, tunneling, water retention systems and blast resistant applications just to name a few.
Helix has undergone extensive laboratory and field-testing. While the behavior of Helix cannot be fully captured using legacy conventional testing methods, Helix meets all industry standards and has been evaluated using standard testing methods including: ACI 318, ASTM A820, ASTM C76, ASTM C116, ASTM C478, ASTM C913, ASTM E1111, ASTM C1227, ASTM C1399, ASTM C1609, ASTM C1550, CE EN 14889-1, IBC 2009, ICC A208, JSCE SF4, SDI 5.5, TR-34, and UL263.
Helix Steel has developed a new generation of material testing methods designed specifically for use with advanced non-linear finite element analysis.
The use of Helix does not change the way concrete is poured or finished. Finishing is no different than standard finishing practices for plain concrete. Helix allows the use of more advanced finishing procedures and equipment such as a laser screed. Helix doesn't clump or stand up when finished and does not affect the use of pumping equipment.
Extensive academic research has been done on Twisted Steel Fibers sometimes referred to as “Torex” (the original name of Helix) going back to the early 1990s. While much of the work done focuses on high-end applications with high dosages the research does firmly demonstrate the superiority of the Helix Steel’s patented twisted fiber designs over steel fibers.
For more technical details, answers to additional common questions and for dosage information, please review the downloadable PDFs on this page.
Watch the below video for an introductory presentation to Helix.