AAI Anchor Spacing, Edge Distance & Embedment Depth 2

Question 1

When installing adhesive anchors at a corner where two free edges are present, the anchor capacity is affected because:

Accepted Answer

Both edge distances influence the concrete breakout capacity, resulting in greater reductions

Answer

The drilling equipment cannot be properly positioned at corners

Answer

Corner locations have higher concrete compressive strength due to formwork pressure

Answer

Adhesive curing is slower at corners due to reduced heat dissipation

Question 2

The minimum spacing between adhesive anchors is most commonly expressed as a multiple of:

Accepted Answer

The effective embedment depth (h_ef)

Answer

The anchor rod diameter (d_a)

Answer

The anchor hole diameter (d_o)

Answer

The concrete compressive strength (f'c)

Question 3

Which primary U.S. code document governs the design requirements for post-installed adhesive anchor spacing and edge distances in concrete structures?

Accepted Answer

ACI 318 — Building Code Requirements for Structural Concrete, Chapter 17

Answer

ACI 530 — Building Code Requirements for Masonry Structures

Answer

ASCE 7 — Minimum Design Loads for Buildings and Other Structures

Answer

ASTM E488 — Standard Test Methods for Strength of Anchors in Concrete

Question 4

An installer notices that achieving the specified center-to-center spacing is impossible due to existing reinforcement. The correct action is to:

Accepted Answer

Notify the engineer of record and await revised instructions before drilling

Answer

Reduce the anchor diameter to fit between the rebar

Answer

Relocate all anchors to the opposite face of the member

Answer

Increase the embedment depth to compensate for reduced spacing

Question 5

What effect does increasing the embedment depth of an adhesive anchor typically have on its tensile (pullout) capacity?

Accepted Answer

Increases capacity because more bond area is available for load transfer

Answer

Decreases capacity because deeper holes accumulate more debris

Answer

Has no effect since capacity is governed solely by anchor rod yield strength

Answer

Decreases capacity because deeper adhesive columns are more prone to voids

Question 6

The 'critical edge distance' (c_ac) specified for an adhesive anchor system is determined by:

Accepted Answer

Testing and product qualification per ICC-ES AC308 and published in the product evaluation report

Answer

The local building official based on site-specific conditions

Answer

The engineer of record on a project-by-project basis using ACI 318 equations

Answer

OSHA field safety inspectors during installation inspections

Question 7

If an adhesive anchor group must resist combined tension and shear near a free edge, which interaction condition must the designer evaluate?

Accepted Answer

Combined tension and shear interaction per ACI 318-14 Section 17.6

Answer

Compression and torsion interaction at the anchor head

Answer

Biaxial bending interaction per ACI 318 Chapter 10

Answer

Punching shear interaction per ACI 318 Chapter 8