Like all of HK’s products, the Composite Action System is patented and tested. This tie is designed to create a structurally-composite concrete sandwich panel. Composite action means the two wythes of concrete are acting together structurally thus allowing a thinner panel to be created. The tie is pushed through the foam layer until properly seated, immediately after the bottom wythe of concrete is placed.
- Holds a both wythes of concrete affixed to the panel without the need for thermally inefficient metal connectors or solid concrete sections
- High strength and low thermal conductivity
- High-performance, alkaline & moisture corrosion resistant, engineered thermoplastic reinforced with glass fibers
- In-place temperature range: -40°F to 200°F
HK Composite Action Ties
- Quad Tip 1″ Tie (CA25)
- Quad Tip 1.5″ Tie (CA40)
- Quad Tip 2″ Tie (CA50)
- Quad Tip 3″ Tie (CA75)
- Quad Tip 4″ Tie (CA100)
- Quad Tip 5″ Tie (CA125)
- Quad Tip 6″ Tie (CA150)
All Composite Action Ties can be customized depending on project design and specifications. If you need a product not listed above, contact our talented engineers so we can meet your needs.
Construction Consulting Laboratory International (CCLI) tested three full scale precast concrete sandwich wall panels by applying positive load by uniform pressure. The panels were designed by CEG and Manufactured by Meridian Precast located in Waco, TX. The panel dimensions are 8 ft. wide and 32 ft. high. Test panels were installed into a test chamber and loaded to failure while deflections recorded during loading.
Below is a graph comparing the test data to a serious of theoretical load-deflection curves generated by Lecwall software for assuming 70% to 100% composite action. (Test data and theoretical curves were smoothed for clarity.)
The HK Composite Action ties are tested in accordance with the ICC-ES AC 320. The table below displays the testing comparisons of some of our Composite Action ties.
You can view more complete testing reviews for each tie on their individual product pages.
|Tie Length:||5.5 in / 140 mm||6.5 in / 165 mm||7.5 in / 191 mm|
|Embedment Depth (head):||1.75 in / 45 mm||1.75 in / 45 mm||1.75 in / 45 mm|
|Embedment Depth (tip):||1.75 in / 45 mm||1.75 in / 45 mm||1.75 in / 45 mm|
|Dimensions Through Foam:||0.47 in x 3.13 in /|
12 mm x 80 mm
|0.47 in x 3.13 in /|
12 mm x 80 mm
|0.47 in x 3.13 in /
12 mm x 80 mm
|Insulation Thickness:||2 in / 50 mm||3 in / 75 mm||4 in / 100 mm|
|Wythe 1:||2–6 in /|
|2–6 in /|
|2–6 in /
|Wythe 2:||2–6 in /|
|2–6 in /|
|2–6 in /
|Ultimate Tension Capacity: ¹||5,900 lb / 26.1 kN||5,900 lb / 26.1 kN||5,900 lb / 26.1 kN|
|Ultimate Shear Capacity: ²||5,315 lb / 23.7 kN||4,902 lb / 21.8 kN||4,489 lb / 20.0 kN|
|95% Confidence 5% Fractile Shear Strength: ²||5,183 lb / 23.1 kN||4,720 lb / 21.0 kN||4,257 lb / 18.9 kN|
|Alkaline Resistance: ³||Excellent||Excellent||Excellent|
|Impact Resistance: ⁴||Excellent||Excellent||Excellent|
|Fire Performance:||Resist 300-lb tension load for over 90 minutes when fire tested per Section 7.4.3 of ASTM E1512-01||Resist 300-lb tension load for over 90 minutes when fire tested per Section 7.4.3 of ASTM E1512-01||Resist 300-lb tension load for over 90 minutes when fire tested per Section 7.4.3 of ASTM E1512-01|
|Thermal Conductivity:||1.75 Btu-in/hr-ft²°F|
¹ Testing by Construction Consulting Laboratory, International, Carrollton, TX, f’c = 5,000
² HK CA Tie 5% Fractile Testing, Durham School of Architectural Engineering and Construction, University of Nebraska-Lincoln, Lincoln, NE, May 12, 2021, f’c = 5,000
³ 96.2% retained strength after 3,000 hours of conditioning in pH12 solution, Testing of HK Composite Low Conductivity Ties to ICC-ES AC320 Criteria, Report Number: ESP014387P.1, March 5, 2014, Element Materials Technology, 662 Cromwell Avenue, St. Paul, MN
⁴ The un-notched Izod Impact of the base resin is 21.0 ft-lb/in (1,120 J/m)
U.S. Patent 6,895,720 B2
Made in the USA
Frequently Asked Questions
How do HK Ties work?
View the "How it Works" page to see a demonstration video.
Are HK Ties Tested?
Yes. Our patented low-conductivity polymer systems excel in tests for tensile strength, shearing, concrete pull-out, long term alkaline resistance, fire, cyclic fatigue, and many building code certifications. See HK testing reports here.
Do I save money using HK Ties?
Yes. Our simple manufacturing process used to make HK Ties, called thermoforming, reduces our output costs which increases your “bang for your buck”. Not only that, HK Ties reduce the R-value of the wall by less than 1% compared to as much as 75% reduction with steel and/or typical solid concrete section ties. This results in maximum energy savings!
Also, because HK Ties are manufactured using a simple process, they cost less to produce and we can pass along that savings to our users.
Does HK use fiberglass to make Ties?
Being the best means being different; we don’t use fiberglass in our HK Standard Ties. HK Standard Ties are made from an engineered reinforced thermoplastic, enabling our standard ties to be more durable than competitor ties. In contrast, HK Vertical Pour/ Modular Precast Ties and Composite Action Ties are made from a fiberglass reinforced thermoplastic.
Regardless of the engineered make-up, all HK Ties are designed to resist impact and shock loads during precast panel transportation and erection. The resin retains its strength at high temperature and provides maximum long-term chemical resistance.
Construction jobs come in many different shapes and sizes. Different jobs require different ties. Our HK Tie experts are here to help you find the best tie for your project. Contact us today!
Is plastic as strong as fiberglass?
Fiberglass is plastic—reinforced with glass fiber. Strength-wise, it is true that some types of fiberglass have a higher material tensile strength than HK Tie resins. However, high material tensile strength is only one factor responsible for the tensile capacity of a tie. The minimum cross-sectional area and manufacturing processes together with inherent material properties ultimately determine tie strength. The actual delivered tensile and shear strengths of HK Ties are many times higher than required.
The plastic used for the HK Standard Ties is a high-impact, high-temperature, chemical resistant engineered thermoplastic. The plastic used for the HK VP (Vertical Pour) and Modular Precast Ties is glass fiber reinforced.
Every job is another dragon to slay. We will help you get the job done cost-effectively, safely and as quickly as possible. Contact us today!
Can my project receive LEED points for using the HK Building system?
Yes. With the HK building system, you can go green and save green. HK Green Building Insulation Systems are designed to meet green building standards for better thermal protection and energy performance from longer-lasting, environmentally benign building materials.
The system is created using extruded polystyrene foam (XPS) insulation in-between two concrete wythes. Highly durable HK Ties, inserted into the XPS, have been proven to reduce the insulation R-value by less than 1% Compare that to as much as 75% reduction with steel and/or typical solid concrete sections! This small change can make a big difference! Start saving and contact us today.
Does HK offer a turnkey solution?
Yes. Our turnkey foam fabrication solution is one of many reasons why we are the concrete sandwich construction industry leader. We specialize in and have extensive experience with foam fabrication processes.
When the foam is fabricated, boards are pre-cut to fit architectural drawings. We make it easy for you as we provide specific foam layout drawings and pre-drill the XPS energy-efficient insulation board to accommodate HK Tie insertion. HK insulation foam boards come to the job site, placement ready. Bye, bye head scratching and complicated puzzles, hello revenue.