# Product Technical Guides : US-EN Post-Installed Rebar Guide - Page 11

Post-Installed Reinforcing Bar Guide
 2.0 HOW ARE THEY DESIGNED ? Development length of # 9 existing reinforcing per Eqs . ( 25.4.2.4a & b ): l d = 3 f y ψ s d b 40 λ c b + K tr # 9 bars have 1-1 / 2 in . cover , transverse reinforcing is # 5 @ 16 in . on center ( see Figure 13 ) d b
40A tr
40 x 0.31
K tr
= = = 0.78 s ∙ n 16 x 1
3 60000 0.8 l d
= 0.625 = 14 in .
40 1.0√4000 2.5
 1.128 + 1.5 + 0.78 C b + K tr = d b 2 1.128 = 2.55 ∴ use 2.5
Note : locate ( e ) reinforcing prior to drilling .
37 in .
14 in .
( E ) slab reinforcing
( N ) # 8 @ 12 in . o . c . installed in drilled holes with Hilti HIT-RE 500 V3
 l d = 3 f y ψ s d b 40 λ c b + K tr
 d b ( E ) slab d = 8 in .
3 60000 1.0 l d
= 1.128 = 32 in .
40 1.0√4000 2.5
Tension lap length ( Class B ) of # 8 new reinforcing per Table 25.5.2.1 :
1.3 60000 1.0
1.3l d
= 1.0 = 37 in . > 32 ∴ use 37 in .
40 1.0√4000 2.5
2 in .
2 in .
12 in . typ .
( E ) slab
16 in . typ .
Figure 13 — Location of new bars ( not to scale ).
( E ) slab reinforcing
( N ) # 8 bars embedded in drilled holes with Hilti HIT-RE 500 V3 adhesive anchor system
4i n . max .
( N ) # 5 bars embedded in drilled holes with Hilti HIT-RE 500 V3 adhesive anchor system
Mechanically roughened surface , 1 / 4 in . amplitude
( E ) wall
Figure 14 — Cantilevered balcony detail ( not to scale ).
( N ) # 5 @ 16 in . o . c . installed in drilled holes with Hilti HIT-RE 500 V3
Step 4 : Specification Provide post-installed dowels at size , spacing and embedment as indicated on construction documents ( see Figure 14 ).
Dowels : ASTM A615 Grade 60
Anchoring system : Hilti HIT-RE 500 V3 epoxy , install as per Manufacturer`s Printed Installation Instructions ( MPII ), permissible concrete temp . range for installation : 55˚F - 90˚F , concrete shall be dry during dowel installation .
Drill holes using a rotary-hammer drill with carbide bit . Locate existing reinforcing prior to drilling – do not damage ( E ) reinforcing without prior authorization of the EOR .
Bottom bars : Development length of # 5 bars with 1.5 in . cover Assume K tr = 0 ( conservative )
 0.625 + 1.5 + 0 C b + K tr = d b 2 0.625 = 2.9 ∴ use 2.5
9 2021