AAI AAI Load Calculations & Structural Requirements 2

Question 1

In seismic design categories C through F, what additional requirement applies to adhesive anchor installations?

Accepted Answer

Only adhesives with seismic qualification testing (ICC-ES AC308) may be used

Answer

IBC and ACI 318 require seismically qualified adhesives tested per AC308 in Seismic Design Categories C–F due to the cyclic and dynamic nature of earthquake loading.

Question 2

What does the phi (φ) factor in ACI 318 anchor design represent?

Accepted Answer

A strength reduction factor that accounts for variability and uncertainty in capacity

Answer

The φ factor is a probabilistic strength reduction that ensures the design capacity (φNn) is less than the nominal capacity (Nn), accounting for material variability, workmanship, and model uncertainty.

Question 3

For combined tension and shear loading on an adhesive anchor, which interaction equation does ACI 318 require?

Accepted Answer

(Nua/φNn)^(5/3) + (Vua/φVn)^(5/3) ≤ 1.0

Answer

ACI 318 uses a 5/3 power interaction equation for combined tension-shear, which is less conservative than a linear interaction when one load component is dominant.

Question 4

What is the 'critical edge distance' (cac) for an adhesive anchor, and why does it matter?

Accepted Answer

The minimum edge distance to develop full characteristic bond strength without reduction

Answer

When the actual edge distance is less than cac, the characteristic bond strength must be reduced to account for reduced confinement near the concrete edge.

Question 5

How does the anchor installation condition (Category 1, 2, or 3) affect the anchor design in ACI 318?

Accepted Answer

Higher installation category numbers reflect less controlled conditions and require lower φ factors

Answer

ACI 318 ties the φ (strength reduction) factor to installation and inspection conditions — Category 1 with continuous inspection permits higher φ values than Category 3 with no special inspection.

AAI - American Concrete Institute Adhesive Anchor Installer Certification Practice Test

AAI - American Concrete Institute Adhesive Anchor Installer Certification Practice Test

AAI AAI Load Calculations & Structural Requirements 2