AAI Anchor Spacing, Edge Distance & Embedment Depth

Question 1

What is the primary reason minimum edge distance requirements exist for adhesive anchor installations?

Accepted Answer

To prevent concrete splitting or breakout failure near the edge

Answer

To reduce the amount of adhesive used

Answer

To allow easier access for drilling equipment

Answer

To comply with aesthetic requirements on visible surfaces

Question 2

The effective embedment depth (h_ef) of an adhesive anchor is measured from:

Accepted Answer

The concrete surface to the tip of the adhesive-bonded portion of the anchor

Answer

The top of the base plate to the tip of the anchor rod

Answer

The underside of the nut to the bottom of the drilled hole

Answer

The concrete surface to the bottom of the drilled hole

Question 3

When adhesive anchors are installed in a group, the minimum center-to-center spacing requirement is intended to prevent:

Accepted Answer

Overlapping bond stress zones that would reduce individual anchor capacity

Answer

Anchors from being installed in the same plane

Answer

Excessive adhesive consumption during installation

Answer

Interference between drilling operations

Question 4

According to ACI 318, what term describes the minimum edge distance below which the anchor capacity must be reduced due to proximity to a free edge?

Accepted Answer

Critical edge distance (c_ac)

Answer

Nominal edge distance

Answer

Factored edge distance

Answer

Design edge distance

Question 5

If an adhesive anchor is installed with an embedment depth less than the minimum specified in the MPII, the installer should:

Accepted Answer

Stop work and consult the engineer of record before proceeding

Answer

Fill the remaining hole with non-shrink grout and proceed

Answer

Add a longer anchor rod to compensate for the shallow embedment

Answer

Apply additional adhesive at the surface to increase bond length

Question 6

The minimum concrete member thickness for adhesive anchor installation is typically specified as a function of:

Accepted Answer

The embedment depth and anchor diameter as specified in the MPII or evaluation report

Answer

The diameter of the anchor rod only

Answer

The compressive strength of the concrete

Answer

The type of adhesive system being used

Question 7

When an adhesive anchor must be placed closer to an edge than the critical edge distance but farther than the minimum edge distance, the design approach is to:

Accepted Answer

Apply a reduction factor to the anchor's tensile and shear capacity

Answer

Use a larger diameter anchor rod to compensate

Answer

Increase the embedment depth proportionally to offset the reduced edge distance

Answer

Install supplemental adhesive on the anchor rod threads