Product Technical Guides : US-EN Cast-In Anchor Channel Fastening Technical Guide | Page 64

1. Anchor Channel Systems 2. HAC Portfolio 3. HAC Applications 4. Design Introduction 5. Base material Table 2.2.10.3 — Channel lip thickness Table 2.2.10.2 — Hilti Channel Bolts dimensions Anchor Channel Profile Units Diameter ø (in) mm mm (in) M16 M20 14 10.4 40-200 (0.55) (0.41) (1.57-7.87) 18.5 (0.73) 33 (1.30) 11.4 40-200 (0.45) (1.57-7.87) 13.9 60-200 (0.55) (2.36-7.87) 1/8 in HAC-50 HAC-50 S (3.10 mm) 5/32 in HAC-60 (4.1 mm) 13/64 in HAC-70 (5.2 mm) Hilti Locking Channel Bolts (HBC-C-N) are suitable for channel profiles HAC-40, HAC-50, HAC-60, & HAC-70. HBC-C-N come in bolt diameters M12, M16, and M20, steel grade 8.8, and HDG finishing. All HBC-C-N are covered by ESR-3520. HBC-C-N can be used to transfer tensile loads, shear loads perpendicular to the longitudinal channel axis, longitudinal shear forces, or any combination of these loads. Transferring the loads takes place via interlock between the head of the HBC- C-N and the channel lips. M20 (7 mm Installation torque of HBC-C Table 2.2.10.5 — Installation torque for Hilti Channel Bolts (HBC-C) Bolt type ft-lb (Nm) ft-lb (Nm) ft-lb (Nm) 52 (70) 78 (105) HAC-70 HAC-40 HAC-50 HAC-60 19 (25) 55 (75) 44 (60) 136 (185) 44 (60) 44 (60) 89 (120) 236 (320) HAC-70 Figure 2.2.11.3 — T-bolt marking. Figure 2.2.11.1 — Head of Hilti Locking Channel Bolt (HBC-C-N). 1 Installation type A: The fixture is in contact with the channel profile and the concrete surface 2 Installation type B: The fixture is fastened to the anchor channel by suitable steel part (e.g. square plate washer), fixture is in contact with the channel profile only 64 Cast-In Anchor Channel Product Guide, Edition 1 • 02/2019 65 HBC-C M20 8.8 ft-lb (Nm) HAC-60 HBC-C M16 50 R HAC-50 HBC-C M16 8.8 Installation torque T inst (Installation type B) 2 Units HAC-40 HBC-C M12 8.8 Installation torque T inst (Installation type A) 1 (5 mm) 9/32 in Although there is minimum t-bolt overhang (Lo) can be zero, for tolerance purposes it is recommended to have a minimum t-bolt overhang. Table 2.2.10.4 provides the minimum t-bolt overhang length. Special markings on the t-bolt aid the installer to ensure the bolt is properly positioned before the installation torque is applied. Moreover, it allows the installer and inspector to identify the type of bolt, after the fixture is installed. 13/64 in M16 Special channel bolt markings (3 mm) Figure 2.2.11.2 — Friction. 1/8 in M12 Minimum nominal overhang, L o Although longitudinal shear forces may be justified via friction, AC232 requires a positive connection between T-bolt and channel lip. Due to different installation uncertainties, long-term relaxation, and performance variance, Hilti does not recommend the use of friction as a means of transferring longitudinal loads, especially seismic loads. Hilti locking channel bolt diameter (mm) The notches created in the channel lips reduce the moment of inertia of the channel profile. Therefore, the flexural strength of the anchor channel in tension is reduced by 10-15 percent, depending on the anchor channel profile size. Corrosion of the notches is not a concern due to the tight sealing that occurs during the installation torque. Can longitudinal shear loads be resisted via friction? The inside head of the HBC-C-N has 4 hardened notches. After the required installation torque is applied, the head of the t-bolt “bites” into the channel lips, creating four (4) - 2 mm deep “notches” in the channel lip. Hence, a positive connection between channel lip and t-bolt head is created. The longitudinal shear resistance of the HBC-C-N and HAC is achieved via mechanical interlock between the channel lips and head of the notched bolt. The load transfer mechanism ensures full load capacity, even if the nut experiences up to 50 percent relaxation. Table 2.2.10.4 — Recommended t-bolt overhang, L o 14. Design Example According to AISC Steel Construction Manual, 13th Edition, Section 14-10 “Adequate thread engagement for anchor rods is identical to the condition described in the RCSC Specification as adequate for steel to steel structural joints using high strength bolts: having the end of the [anchor rod] flush with or outside the face of the nut”. Figure 2.2.10.3 – Overhang of Hilti Channel Bolts (HBC-C). 13. Field Fixes Longitudinal load transfer mechanism If needed, the excess at the end of the bolt can be cut-off. The nut shall be fully engaged. The outside face of the head of the t-bolt has special markings to identify the t-bolt type and proper head orientation of the t-bolt. If the t-bolt is to be cut or grind, inspect and ensure the orientation and t-bolt type is as specified prior to any work on the t-bolt. If the marking on the t-bolt are removed, proper inspection is not possible. Proper corrosion protection shall be required. 12. Instructions for Use 2.2.11 HILTI LOCKING CHANNEL BOLTS: HBC-C-N Minimum t-bolt overhang There is no maximum thread protrusion limitation from the standpoint of the function of the bolt. 11. Best Practices (in) M12 7/64 in (2.6 mm) 10. Design Software HBC-C HAC-40 HAC-50 HAC-50 S HAC-60 HAC-70 L 9. Special Anchor Channel Design mm b 2 Channel lip thickness, L th HAC-40 k b 1 Anchor Channel profile 8. Reinforcing Bar Anchorage Channel Bolt Channel bolt length Dimensions 7. Anchor Channel Design Code Hilti Channel Bolt Length (HBC-C) 6. Loading