Table 5 — Steel design strength for Hilti HIT-Z and HIT-Z-R rods 1 , 2
Nominal anchor diameter in .
3 / 8
1 / 2
5 / 8
3 / 4
Tensile 3
ϕN sa lb ( kN )
HIT-Z carbon steel rod
Shear 4
ϕV sa lb ( kN )
ACI 318 Chapter 17 Based Design
Seismic Shear 5
ϕV sa , eq lb ( kN )
Tensile 3
ϕN sa lb ( kN )
HIT-Z-R stainless steel rod
Shear 4
ϕV sa lb ( kN )
Seismic Shear 5
ϕV sa , eq lb ( kN )
4,750 |
1,930 |
1,255 |
4,750 |
2,630 |
2,080 |
( 21.1 ) |
( 8.6 ) |
( 5.6 ) |
( 21.1 ) |
( 11.7 ) |
( 9.3 ) |
8,695 |
3,530 |
2,295 |
8,695 |
4,815 |
3,610 |
( 38.7 ) |
( 15.7 ) |
( 10.2 ) |
( 38.7 ) |
( 21.4 ) |
( 16.1 ) |
13,850 |
5,625 |
3,655 |
13,850 |
7,670 |
4,985 |
( 61.6 ) |
( 25.0 ) |
( 16.3 ) |
( 61.6 ) |
( 34.1 ) |
( 22.2 ) |
20,455 |
8,310 |
5,400 |
20,455 |
11,330 |
7,365 |
( 91.0 ) |
( 37.0 ) |
( 24.0 ) |
( 91.0 ) |
( 50.4 ) |
( 32.8 ) |
1 See section 3.1.8 to convert design strength value to ASD value . 2 HIT-Z and HIT-Z-R rods are to be considered brittle steel elements . 3 Tensile = ϕ A se , N f uta as noted in ACI 318 Chapter 17 . 4 Shear values determined by static shear tests with ϕV sa
≤ ϕ 0.60 A se , V f uta as noted in ACI 318 Chapter 17 .
5 Seismic Shear = α V , seis ϕ Vsa
: Reduction for seismic shear only . See section 3.1.8 for additional information on seismic applications .
Hilti HIT-Z ( -R ) rod permissible combinations of edge distance , anchor spacing , and concrete thickness
The Hilti HIT-Z and HIT-Z-R anchor rods produce higher expansion forces in the concrete slab when the installation torque is applied . This means that the anchor must be installed with larger edge distances and spacing when compared to standard threaded rod , to minimize the likelihood that the concrete slab will split during installation .
The permissible edge distance is based on the concrete condition ( cracked or uncracked ), the concrete thickness , and anchor spacing if designing for anchor groups . The permissible concrete thickness is dependent on whether or not the drill dust is removed during the anchor installation process .
Step 1 : Check concrete thickness
When using Hilti HIT-Z and HIT-Z-R anchor rods , drilling dust does not need to be removed for optimum capacity when base material temperatures are greater than 41 ° F ( 5 ° C ) and a hammer drill with a carbide tipped drill bit is used . However , concrete thickness can be reduced if the drilling dust is removed . The figure below shows both drilled hole conditions . Drilled hole condition 1 illustrates the hole depth and concrete thickness when drilling dust is left in the hole . Drilled hole condition 2 illustrates the corresponding reduction when drill dust is removed by using compressed air , Hilti TE-CD or TE-YD Hollow Drill Bits with a Hilti vacuum . Figure 5
Refer to tables 6 to 9 in this section for the minimum concrete thicknesses associated with the Hilti HIT-Z ( -R ) rods based on diameter and drilled hole condition .
Step 2 : Check edge distance and anchor spacing
Tables 6 to 9 in this section show the minimum edge distance and anchor spacing based on a specific concrete thickness and whether or not the design is for cracked or uncracked concrete . There are two cases of edge distance and anchor spacing combinations for each embedment and concrete condition ( cracked or uncracked ). Case 1 is the minimum edge distance needed for one anchor or for two anchors with large anchor spacing . Case 2 is the minimum anchor spacing that can be used , but the edge distance is increased to help prevent splitting . Linear interpolation can be used between Case 1 and Case 2 for any specific concrete thickness and concrete condition . See the following figure and calculation which can be used to determine specific edge distance and anchor spacing combinations .
38 Anchor Fastening Technical Guide Edition 22 | 3.0 ANCHORING SYSTEMS | 3.2.2 HILTI HIT-HY 200 A / R V3 Hilti , Inc . 1-800-879-8000 | en español 1-800-879-5000 | www . hilti . com | Hilti ( Canada ) Corporation | www . hilti . ca | 1-800-363-4458