Product Technical Guides : US-EN Cast-In Anchor Channel Fastening Technical Guide | Page 300

1. Anchor Channel Systems 2. HAC Portfolio 3. HAC Applications 4. Design Introduction 5. Base material 6. Loading æ c a2, max - b ch h - 2h ch ö , c a1, red = max ç ÷ 2 2 ø è 8. Reinforcing Bar Anchorage A' 1 = 0.25 × s 1 = l in 6 A' 2 = 1.25 × s 5 = l in 6 A' 3 = 0.75 × s 1 = l in 2 k = 9. Special Anchor Channel Design 10. Design Software Determination of anchor and rebar forces acting on the channel f y = yield strength of 1 2 = A' 1 + A' 2 + A' 3 3 re inf orcement [ psi ] f c = concrete cylinder compressiv e strength [ psi ] K tr = 0 no transverse re inf orcement is Figure 9.6.2.11 — Developement taken int o account The tension load on the rebars is also calculated with the model of AC232, with a modification of ℓ in , as specified below. In case of forces acting toward the inside of the slab, rebars forces are added in a similar way as for the anchors. Negative resulting forces on the rebars are neglected. EDGE Steel strength of rebar : Ф N s,R c b £ 2 . 5 influence of concrete cover d b c b = to be determined taking into account th e rebar position and the member geometry If several tension or shear loads are acting on the channel a linear superimposition of the rebar forces for all shear loads is assumed. Ф N s,R > N ö ÷ ÷ . d b ³ 12 in ö ÷ ÷ ÷ ø ø l = 0 . 75 for all - lightweigh t concrete In combination with the EDGE front plate all the actions on the anchors (tension, perpendicular and longitudinal shear) are calculated with the method of AC232. Figure 9.6.2.9 — Example for the calculation of rebar forces in accordance with the triangular load distribution method for an anchor channel with four rebars. The influence length is assumed as ℓ in = 1.5s 14. Design Example 13. Field Fixes l = 1 . 0 for normal - weight concrete æ e ö æ 1 ö æ e ö æ 1 ö æ 2 ö N ua r ,3 = ç ÷ . ç ÷ . V ua b . ç s + 1 ÷ = ç ÷ . V ua b . ç s + 1 ÷ è 2 ø è 3 ø è z ø è 3 ø è z ø b 12. Instructions for Use æ ç y t . y e . y s 3 f y l d, prov ³ l d = ç . . ç 40 l . f ' c æ c d + K tr ç ç è d b è æ e ö æ 1 ö æ e ö æ 1 ö æ 2 ö N ua r ,1 = ç ÷ . ç ÷ . V ua b . ç s + 1 ÷ = ç ÷ . V ua b . ç s + 1 ÷ è 6 ø è 3 ø è z ø è 9 ø è z ø e e 5 2 5 æ ö æ ö æ ö æ ö æ ö N ua r ,2 = ç ÷ . ç ÷ . V ua b . ç s + 1 ÷ = ç ÷ . V ua b . ç s + 1 ÷ è 6 ø è 3 ø è z ø è 9 ø è z ø Ψ c,V = 1.0 modification factor for cracked concrete, always 1.0 11. Best Practices If two corners are available, a Ψ co,V for second corner is calculated and multiplied by the first. For narrow members (c a2,max < c cr,V ) with a thickness h to be determined taking into account th e rebar position and the member geometry ua Y t = 1.0 for other situations The capacity of steel rebar Hilti Method is in accordance to ESR- 3520 Sec. 4.1.3.3.3. Please refer to table 2.3.23.1 of chapter 02. Y e = 1.0 for uncoated reinforcem ent Y s = 0.8 for No. 6 and smaller bars (db £ 0.75in.) Y s = 1.0 for No. 7 and larger bars (db ³ 0.875in.) db = reinforcem ent diameter [in.] l d, prov = l R - c a1 provided length Figure 9.6.2.8 — Load Path. N r ua, i = k . A ' i . V b ua (( e s / z ) + 1 ); Where: Figure 9.6.2.10 — Anchor reinforcement to resist shear loads. k = 1 å A ' Equation 9.6.2.1 l in , r = ( 0 . 2 + 0 . 004 c a 1 ) l in £ l in in in V b ua = factored tension load on channel bolt , lb t = anchor plate thickness (f y = ) s d = l d, prov . p . d b . the EDGE re inf orcement N P , R = e c = dist between concrete top surface and anchor plate bottom surface z = 0 . 85 . h ' d b £ min( 2 . h ef , 2 . c a 1 ) 2 h = actual member depth h ' = h - h ch - h ch = height of anchor channel under considerat ion c a 1 = edge dis tan ce of the anchor under considerat ion d t + h ch + b + 0 . 0394 2 2 0787 e e s s = = e e c c + + 2 t 2 t + + h h ch ch + + d 2 3 b 2 d b + + 0 . 0.0787 for EDGE , in for for EDGE EDGE , in C , in 4 . s d = l d , prov . p . d b . 10 æ c d ö 1 . l . f ' c . min ç , 2 . 5 ÷ . 3 è d b ø y t . y e . y s ФV ca > V aua re inf orcement f = 0 . 75 In combination with the EDGE front In combination with the EDGE front plate, it is not allowed to consider also the supplementary reinforcement. Ф N p,R > N rua In general an verification acc. to ACI 318-11 is performed by comparing a development length with a provided length. Due to the fact that the provided length as well as the diameter of the rebar is fixed a possible (virtual) “anchorable” force (stress) in the rebar is “back”- calculated. For the verification this “anchorable” force N p.R will be compared with the acting force N rua on the rebar. p . d 2 s , R 10 æ c d ö 1 . l . f ' c . min ç , 2 . 5 ÷ . 3 è d b ø y t . y e . y s Anchor reinforcement anchorage: ФV ca N r ua = diameter of the EDGE EDGE pull-out strength of rebar : Ф N p,R h ef = embedment depth of the anchor 300 l d.prov = 12 in re inf orcement 0 . 05 0.5 l in n = 4.93. . s . s 0 . 5 < s li 4 . 93 . I Iy y 0.05 e s = e c + Anchorable force : . f y 4 = no min al yield strength of d = diameter of the EDGE r , i s = anchor spacing , f y p . d 2 Without the EDGE front plate, with and without lip strengthening element (clip), ESR-3520 applies Not Permitted Anchor reinforcement anchorage: ФV ca Pullout: ФN p,R Cast-In Anchor Channel Product Guide, Edition 1 • 02/2019 301 A’ r,i ordinate at the position of the rebar i assuming a triangle with the unit height at the position of load V ua and the base length 2·ℓ in,r with ℓ in,r determined in accordance with (Equation 9.6.2.1). Examples are provided in Figure 9.6.2.9. N s, R = f = 0.75 reduction factor f seismic = 0.75 additional reduction factor for seismic • Rebar tensile forces (Hilti Method): The rebar tensile forces N rua,i are calculated with the bolt factored shear load V bua,y with the same method, based on a triangular distribution, described in the previous paragraph. In this case the base of the triangle ℓ in is reduced as specified in eq. (2) and loads are also increased by the ratio (es / z + 1) to take the load eccentricity into account (see in Figure 9.6.2.10). Rebar: ΦN s,R