Concrete Accessories
DYWIDAG Expansion Anchor
5/8“ Expansion Anchor
DYWIDAG Expansion Anchor can be used with 5/8“THREADBAR ®. These anchors are used in many applications including one sided forming off existing concrete or temporary tiedowns in existing slabs. The fast DYWIDAG thread pattern (21/2 threads per inch) provides quick installation and stripping. Available in two bore hole diameters (33 – 36 mm and 35 – 38 mm), simply determine the estimated compressive strength of existing concrete and the depth of the hole.
Embedded Anchor Capacities
Ultimate load Fu in kips (use appropriate factor of safety)
The capacity of embedded anchors in concrete is estimated using the truncated cone break-out failure mechanism.
The concrete cone angle can be assumed as a = 55° to the axis of the load. The ultimate load can be computed using the equatation according to ACI 318 appendix D.
* The spacing of expansion anchors shall not be less than 3 times the effective embedment length.
| Drill hole depth [in] | Concrete strength [psi] | |||||||
| 3000 | 3500 | 4000 | 4500 | 5000 | 5500 | 6000 | ||
| 8 | 4.8 | 5.2 | 5.6 | 5.9 | 6.2 | 6.6 | 6.8 | 5/8" |
| 9 | 7.4 | 8.0 | 8.6 | 9.1 | 9.6 | 10.1 | 10.5 | |
| 10 | 10.4 | 11.2 | 12.0 | 12.8 | 13.4 | 14.1 | 14.7 | |
| 11 | 13.7 | 14.8 | 15.8 | 16.8 | 17.7 | 18.5 | 19.4 | |
| 12 | 17.2 | 18.6 | 19.9 | 21.1 | 22.3 | 23.3 | 24.4 | |
| 13 | 21.1 | 22.8 | 24.3 | 25.8 | 27.2 | 28.5 | 29.8 | |
| 14 | 25.1 | 27.2 | 29.0 | 30.8 | 32.5 | 34.0 | 35.6 | |
| 15 | 29.4 | 31.8 | 34.0 | 36.1 | 38.0 | 39.9 | 41.6 | |
| 16 | 34.0 | 36.7 | 39.2 | 41.6 | 43.9 | 46.0 | 48.0 | 7/8" |
| 17 | 38.7 | 41.8 | 44.7 | 47.4 | 50.0 | 52.4 | 54.7 | |
| 18 | 43.6 | 47.1 | 50.4 | 53.5 | 56.3 | 59.1 | 61.7 | |
| 19 | 48.8 | 52.7 | 56.3 | 59.7 | 63.0 | 66.0 | 69.0 | |
| 20 | 54.1 | 58.4 | 62.5 | 66.3 | 69.8 | 73.2 | 76.5 | |
| 21 | 59.6 | 64.4 | 68.8 | 73.0 | 76.9 | |||
| 22 | 65.3 | 70.5 | 75.4 | |||||
| 23 | 71.1 | 76.8 | ||||||
| 24 | 77.1 | |||||||
| Assume expansion shell length 5“ Equation (ACI 318 appendix D): Fu = k * √fc‘ * L32 Fu = ultimate load [lbf] L = effective embedment length [in] k = 17 factor for post-installed anchor √fc‘ = concrete shear stress [psi] | Example: |
| Safe working load = Fu / safety factor Drill hole depth: Add up expansion shell length (approx. 5“) and effective embedment length | |