ACI Adhesive Anchor Installer Certification Practice Exam

Which installation factor does NOT influence the strength of the adhesive anchor bond?

1. Drilling of the hole before the MPII

2. Cleaning the hole following the MPII

3. Injecting the adhesive following the MPII

4. Mixing the adhesive incorrectly

The correct answer is: Drilling of the hole before the MPII

The reason the drilling of the hole before the Minimum Pullout Installation Interval (MPII) does not influence the strength of the adhesive anchor bond is that the strength of the bond primarily depends on the cleanliness and preparation of the hole rather than the timing of the drilling itself. The MPII represents the minimum time required after the adhesive has been injected before the anchor can be loaded. Factors such as cleaning the hole, injecting the adhesive properly, and mixing the adhesive correctly directly affect how well the adhesive bonds to the surrounding material and the anchor itself. Drilling a hole is a preparatory step, and it is essential that the hole is clean and meets the required specifications after drilling before any adhesive is injected. In contrast, improper cleaning and inadequate mixing will directly compromise the bond strength. Therefore, while all installation factors are important, the act of drilling before the MPII pertains to preparation rather than directly influencing the adhesive bond's strength.