Post-Installed Reinforcing Bar Guide
2.0 HOW ARE THEY DESIGNED ?
Step 1 : Determine area of dowel steel required . Existing construction : ( E ) shear wall , 16 in . thick , 4 ksi normal weight concrete
14 " embedment
Reinforcement requirement based on required shear transfer using shear friction |
V u
= 9k / ft 2
|
( N ) # 5 dowel @ 16 " x 12 " |
23 " |
|
Required area of reinforcement per 22.9.4.2 , Eq . ( R22.9.4.2 ) ACI 318-19
Provided area of reinforcement
|
V u
9
A vf
= = 0.2 in 2 / ft 2
Φf y μ 0.75 x 60 x 1.0
# 5 at 16 in . x 12 in . over face of wall .
|
Figure 10 — Dowel detail ( not to scale ). |
roughened surface , 1 / 4 in . amplitude
Hilti HIT-RE 500 V3 Adhesive anchor system in hammer drilled hole
|
Step 2 : Set design conditions .
• Drilling method : Rotary-hammer drilling
• Orientation of connection : Horizontal / wall position
• Installation and in-service temperature : 70˚F
• Type of concrete : Normal weight , 4 ksi
• Condition of concrete : Dry
• Choice of adhesive based on condition : HIT-RE 500 V3
• Type and location of dowels : Hooked bars , in the face of the existing wall at uniform spacing vertically and horizontally
Step 3 : Calculate the required embedment ( development length ). ACI 318-19 development length equation ( 25.4.2.4a ):
Step 4 : Specification Provide post-installed dowels at size , spacing and embedment as indicated on construction documents ( see Figure 10 ).
Dowels : ASTM A615 Grade 60
Anchoring system : Hilti HIT-RE 500 V3 epoxy , install as per Manufacturer`s Printed Installation Instructions ( MPII ), concrete shall be dry during dowel installation unless otherwise permitted in the MPII . Drill holes using a rotaryhammer drill with carbide bit . Locate existing reinforcing prior to drilling — do not damage ( E ) reinforcing without prior authorization of the EOR . ld
=
3 f y ψ s ψ t ψ e ψ g d b d b
3 60000 0.8 l d
=
0.625 = 14 in . ( 23d b ) > minimum l d
= 12 in .
Available end cover = 16 – 14.2 = 1.8 in . Exterior wall exposure , required cover = 1.5 in . ok
Dowel length = 14 + ( 10 – 0.75 ) say 23 in . to outside of standard hook
7 November 2022