AAI Substrate Preparation & Surface Conditions Flashcards

What is the primary reason hole cleaning is critical before installing adhesive anchors?

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.

According to ACI standards, how many times must a drilled hole be blown out with compressed air during the cleaning cycle?

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.

Which substrate condition is generally NOT acceptable for adhesive anchor installation without special provisions?

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.

What tool is used to brush the inside of a drilled hole during the cleaning process?

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.

How does concrete temperature at the time of installation affect adhesive anchor performance?

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.

What is the purpose of verifying the minimum edge distance before drilling for adhesive anchors?

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.