Product Technical Guides : US-EN Cast-In Anchor Channel Fastening Technical Guide | Page 220

1. Anchor Channel Systems 2. HAC Portfolio 3. HAC Applications 4. Design Introduction 5. Base material 6. Loading HAC and HAC-T at intermediate applications are designed in accordance with ESR-3520. Design methodology is fully in accordance with the anchor channel Design Code presented in chapter 7. 8. Reinforcing Bar Anchorage 9. Special Anchor Channel Design 12. Instructions for Use 13. Field Fixes 14. Design Example Obtuse corners: Longitudinal shear analysis Conservatively the side edge distance of C a2 should be assumed as seen in figure: 9.2.2.4 and figure: 9.2.2.5 because of the discontinuity in the propagation of breakout failure plane in perpendicular shear. This will reduce the perpendicular shear capacity by introducing the reduction factor for corner effect. Conservatively the side edge distance of C ’a1 should be assumed as seen in figure: 9.2.2.6 and figure: 9.2.2.7 because of the discontinuity in the propagation of breakout failure plane in longitudinal shear. Having a C ’a1 will reduce the A vc and also reduces V b , (V b basic longitudinal shear capacity depends on the longitudinal distance) which in turn reduces the Longitudinal shear capacity as seen in fig 9.2.2.6. y co,V Figure 9.2.1.2:TOS 11. Best Practices Obtuse corners: Perpendicular shear analysis c cr, V = 0.5 × s cr, V = 2c a1 + b ch in .( mm ) Figure 9.2.1.1: FOS 10. Design Software æ c a2 = ç ç c è cr,V ö ÷ ÷ ø ESR-3520 Equation (36) V cb, x = ( A vc / A vco ) × ψ ed, V × ψ c, V × ψ h, V × ψ parallel, V .V b 0.5 £ 1.0 ESR-3520 Equation (35) ESR-3520 Equation (44) 9.2.2 — H  AC AND HAC-T DESIGN: FACE OF SLAB OUTSIDE CORNER WITH A SINGLE ANCHOR CHANNEL 90° corners Outside corners where only one anchor channel is present are fully covered by ESR- 3520. The design methodology is fully in accordance with the anchor channel Design Code presented in Chapter 7. Figure 9.2.2.4 — Obtuse corner — perpendicular shear —Section view. Figure 9.2.2.6 — Obtuse corner — Longitudinal shear —Section view. AC232 includes design provisions to account for the influence of a corner. The concrete strengths in tension and shear of the anchor channel may be reduced (depending on how far the anchor channel is away from the corner) since the concrete cones may not be fully developed. See chapter 7 for design provisions for corners. Figure 9.2.2.1: 90° Corner with single channel. In PROFIS Anchor Channel, these conditions can be simply modeled by reducing the corner distance. Acute and obtuse corners OPTION II: This is an optimized condition where the analysis of the a 1 anchor is performed using new h ’eff as the new embedment depth with side edge distance of C ’a2 and ignoring the concrete represented by the darker shade of gray. The h eff for rest of the other anchors will not change. This can be solved using hand calculations only. Please contact Hilti for support if any obtuse angle conditions need an optimized solution. Although AC232 does not specifically address acute and obtuse corners, Hilti's general recommendation is to not follow the idealized failure planes but the path of least resistance to assess the concrete volume available for the anchor channel. Upon determination of the corner distance, AC232 provisions can be used to analyze this type of corners. OPTION I. This condition should be modeled in PROFIS anchor channel software with a corner (C a2 ) distance of the closest anchor and the corner. Therefore, the concrete represented by the darker shade of gray shall be ignored. Figure 9.2.2.5 — Obtuse corner — perpendicular shear —Plan view. Figure 9.2.2.7 — Obtuse corner — Longitudinal shear —Plan view. In order to avoid calculating unconservative concrete strength, the path of least resistance for the crack should be always considered. Obtuse corners: Tension analysis Corner distance shall be considered assuming an imaginary edge at the joint of the corner. The following two options that has been illustrated and used for the analysis 220 9.2.1 — HAC AND HAC-T DESIGN: INTERMEDIATE APPLICATIONS 7. Anchor Channel Design Code Figure 9.2.2.2 — Obtuse — Tension-Option I. Figure 9.2.2.3 — Obtuse -Tension-Option II. Cast-In Anchor Channel Product Guide, Edition 1 • 02/2019 221