AAI AAI Substrate Preparation & Surface Conditions 1 — Questions and Answers
Question 1: What is the primary reason hole cleaning is critical before installing adhesive anchors?
- To remove dust and debris that would prevent proper adhesive bond (Correct answer)
- To make the hole larger for easier insertion
- To check the depth of the hole
- To cool the drill bit
Correct answer: To remove dust and debris that would prevent proper adhesive bond
Dust and debris left in the drilled hole create a barrier between the adhesive and the base material, significantly reducing bond strength.
Question 2: According to ACI standards, how many times must a drilled hole be blown out with compressed air during the cleaning cycle?
- At least 3 times (Correct answer)
- At least 2 times
- At least 4 times
- At least 1 time
Correct answer: At least 3 times
ACI and most adhesive manufacturer instructions require at least 3 blow-out cycles alternating with brushing to adequately clean the hole.
Question 3: Which substrate condition is generally NOT acceptable for adhesive anchor installation without special provisions?
- Saturated wet concrete (Correct answer)
- Dry concrete
- Slightly damp concrete
- Oven-dry concrete
Correct answer: Saturated wet concrete
Saturated wet concrete can dilute the adhesive and prevent proper cure; most adhesives require dry or slightly damp conditions unless rated for underwater use.
Question 4: What tool is used to brush the inside of a drilled hole during the cleaning process?
- A wire brush sized to the hole diameter (Correct answer)
- A soft-bristle paintbrush
- A cotton swab
- A wire gauge probe
Correct answer: A wire brush sized to the hole diameter
A wire brush matched to the hole diameter scrubs loose concrete particles from the borehole walls, which compressed air alone cannot remove.
Question 5: How does concrete temperature at the time of installation affect adhesive anchor performance?
- Low temperatures slow cure time and may reduce ultimate strength (Correct answer)
- High temperatures speed cure and always improve strength
- Temperature has no effect on adhesive cure
- Only ambient air temperature matters, not the concrete temperature
Correct answer: Low temperatures slow cure time and may reduce ultimate strength
Adhesives are chemical systems sensitive to temperature; cold concrete slows the curing reaction and can leave anchors under-strength if not accounted for.
Question 6: What is the purpose of verifying the minimum edge distance before drilling for adhesive anchors?
- To prevent concrete splitting and ensure full load transfer (Correct answer)
- To choose the correct drill bit size
- To determine the adhesive volume needed
- To confirm electrical conduit clearance
Correct answer: To prevent concrete splitting and ensure full load transfer
Insufficient edge distance reduces confinement, causing concrete edge breakout before the anchor reaches its rated capacity.
AAI AAI Substrate Preparation & Surface Conditions 1
What is the primary reason hole cleaning is critical before installing adhesive anchors?