Product Technical Guides : US-EN Cast-In Anchor Channel Fastening Technical Guide | Page 176

1. Anchor Channel Systems 2. HAC Portfolio 3. HAC Applications 4. Design Introduction 5. Base material 6. Loading Shear Load Acting Perpendicular to Channel 8. Reinforcing Bar Anchorage Steel 10. Design Software Channel Lip Strength ϕV sl,y Concrete Table 7.4.1.1 — Test program for anchor channels for use in uncracked and cracked concrete (Table 4.1 of AC232). Minimum No. of tests Channel Anchor Material [-] Secion in Annex A [-] psi [N/mm 2 ] inch (mm) [-] [-] [-] [-] 8 7.8 Channel bolt d s strength inch (mm) [-] V ns : Nominal steel strength of anchor channel loaded in shear (lowest value of V sa , V sc , and V Sl ) V ss, M = a . M M ss l , lb(N) ESR-3520 Equation (28) α M = f  actor to take into account the restraint condition of the fixture = 1.0 if the fixture can rotate freely (no restraint) = 2.0 if the fixture cannot rotate (full restraint) æ N ua ö M ss = M 0 ss ç ç 1 - ÷ , lb - in (N - mm) ESR-3520 Equation (29) f N ss ÷ ø è f utb =minimum [(1.9 fyb and 125,000 psi (860 MPa)], psi (MPa)). M 0ss = n  ominal flexural strength of channel bolt according to Table 8-12. = 1.2(S chb )f utb , lbf-in (N-mm) ≤ 0.5N sl. a ≤ 0.5N ss. a ℓ = lever arm, in. (mm) a = internal lever arm, in. (mm) as illustrated in Figure 7.4.1.2 T s = tension force acting on channel lips C s = compression force acting on channel lips Steel failure under Shear load 9 Failure of anchor, failure of connection between anchor and channel, local rupture of channel lips 6 Low 0 5 1,8 See AC 232 section 7.8.2 intentionally left blank Concrete failure under shear load 10 Concrete edge failure 7 factor α ch,V c a = c a,min , s = s max , and h > h cr,V Low 0 5 See AC 232 section 7.10.2 intentionally left blank 1 If the coefficient of variation Vof the failure loads is V ≤ 5 percent, the number of tests can be reduced to n = 3. 6 Tests may be omitted if the nominal shear strength of the channel, V nsy , is taken as < N ns . 7 Tests may be omitted if the nominal strength, V ns,y , is computed in accordance with Eq. (D-24a, ACI 318-05,-08), (D-33a, ACI 318-11), (17.5.2.10.2, ACI 318-14) with αch,v= 5.6 lbf 1/2 /in 1/3 (α ch,v = 4.0 N 1/2 /mm 1/3 for SI) (Normal weight concrete) 8  Five tests need to be conducted with the channel bolt positioned over the anchor and an additional five tests with the channel bolt positioned midway between the two anchors, unless footnote 1 applies. 176 Figure 7.4.1.2 - Definition of internal lever arm. Cast-In Anchor Channel Product Guide, Edition 1 • 02/2019 177 11 7.10 ∆w If the fixture is not clamped against the concrete but secured to the channel bolt at a distance from the concrete surface (e.g. by double nuts), the nominal strength of a channel bolt in shear, V ss,M , shall be computed in accordance with Eq. (28). Tests 8 can be omitted if the nominal shear strength of the channel, V ns,y , is taken as ≤ N ns . V ns is the nominal steel strength of anchor channel loaded in shear (lowest value of V sa , V sc , and V sl . N ns is the nominal steel strength of the anchor channel loaded in tension (lowest value of N sa , N sc and N sl ). Figure 7.3.1.1— Possible tensile failure modes of an anchor channel. f c ϕV sc,y ≥ V auay f utb shall be taken as the smaller of 1.9 f yb and 125,000 psi (860 MPa) ϕV sa,y ≥ V auay where Anchor strength is determined from Test 8. The test is performed on anchor channels cast into concrete. The nominal strength of a channel bolt in shear, V ss , must be taken from Table 8-12. The maximum value shall be computed in accordance with Eq. 17.5.1.4.1a, ACI 318-14). V ss = 0.6.A se,V .f utb , lbf (N) Figure 7.4.1.1 — Steel failure in shear of anchor channel lip. ϕV ss ≥ V bua ϕV ss,M ≥ V bua The nominal strength of one anchor, V sa,y , and anchor and channel connection V sc,y to take up shear loads perpendicular to the channel must be taken from Table 8-5 for HAC and HAC-T with Hilti channel bolts (HBC-B, HBC-C, HBC-T and HBC-C-N). Test description Bolt Strength ϕV ss , ϕV ss,M Anchor Strength ϕ V sa,y and Anchor and Channel Connection Strength ϕV sc,y 14. Design Example ϕV sl,y ≥ V auay 13. Field Fixes Local rupture of channel lips is determined from Test 8. The test is performed on anchor channels cast into concrete. Test Ref 12. Instructions for Use Steel failure Anchors loaded in shear exhibit steel failure when the edge distance and the embedment depth are sufficiently large, whereby conical spalling of the surface concrete precedes steel failure Figure 7.4.1.1. For a given anchor, steel failure represents a limit on the maximum shear capacity. Anchors made of ductile steels can develop relatively large displacements at failure. Test no. 11. Best Practices The nominal strength of the channel lips to take up shear loads perpendicular to the channel transmitted by a channel bolt, V sl,y , must be taken from Table 8-5 for HAC and HAC-T with Hilti channel bolts (HBC-B, HBC-C, HBC-T and HBC-C-N). Shear (ΦV n,y ) 7.4.1 S  TEEL STRENGTHS IN PERPENDICULAR SHEAR 9. Special Anchor Channel Design 7.4 ANCHOR CHANNEL DESIGN IN SHEAR 7. Anchor Channel Design Code