ACI Post-Installed Anchor Inspector key terms

A fastener installed into hardened concrete after the concrete has cured, rather than cast in place during pouring. It transfers load to the concrete through mechanical interlock, friction, bonding, or a combination.

An anchor positioned in the formwork before concrete is placed, so the concrete hardens around it. It is distinguished from post-installed anchors, which are drilled and set into cured concrete.

A post-installed anchor that develops resistance through expansion, wedging, or keying against the drilled hole wall. Common types include wedge, sleeve, and drop-in anchors.

A post-installed anchor set in a drilled hole filled with a chemical adhesive that bonds the threaded rod or rebar to the concrete. Load transfer depends on the cured adhesive and hole cleanliness.

A mechanical anchor whose expansion is activated by applying a specified installation torque to the nut or bolt. The applied torque drives a wedge or cone to press expansion elements against the hole wall.

A mechanical anchor that keys into a specially formed enlarged cavity at the bottom of the drilled hole, providing mechanical interlock rather than relying on friction along the hole wall.

A post-installed anchor that forms threads in the concrete as it is driven or threaded into a drilled hole, developing resistance through mechanical engagement with the concrete.

The concrete or masonry element into which an anchor is installed and from which it draws its resistance. Its strength, condition, and thickness govern anchor capacity and failure mode.

The measured resistance of concrete to axial compression, typically reported from cylinder or core tests at a specified age. Anchor design capacities are tied to a minimum specified value.

The distance from the center of an anchor to the nearest free edge of the concrete member. Small edge distances reduce capacity and promote concrete breakout or edge failure.

The center-to-center distance between adjacent anchors in a group. Insufficient spacing causes overlapping stress cones and reduces the capacity of each anchor.

The distance the anchor is set into the concrete, measured from the concrete surface to the effective load-transfer point. It directly affects capacity and must match the approved installation instructions.

The depth over which the anchor actually transfers load to the concrete, which may differ from the drilled hole depth depending on anchor type and setting. It is used in capacity calculations.

The total depth of the drilled hole measured from the concrete surface to the bottom. It must meet or exceed the anchor manufacturer's specified minimum, and excess debris must be removed.

The nominal diameter of the drilled hole, which must match the anchor manufacturer's specified bit size. An oversized or undersized hole compromises anchor performance.

The cutting tool used to bore the anchor hole. Its type, diameter, and condition must conform to the anchor manufacturer's requirements, since worn or incorrect bits produce out-of-tolerance holes.

A rotary-percussion drilling method that fractures concrete as it cuts. Some adhesive anchor systems prohibit or restrict it because the roughened, cracked hole wall can affect bond.

A drilling method using a hollow bit with diamond abrasive segments that cuts a smooth cylindrical hole. It is often required for certain adhesive anchors and large-diameter holes.

The process of removing dust, debris, and water from a drilled hole before installing an anchor, typically by brushing and blowing or vacuuming. It is critical for adhesive anchor bond strength.

The working time after mixing an adhesive during which the anchor must be inserted and positioned before the adhesive begins to stiffen. Exceeding it prevents proper insertion and wetting.

The period an adhesive anchor must remain undisturbed after installation before it can be loaded or torqued. Cure time depends on product, temperature, and hole conditions.

The torque value specified by the anchor manufacturer and applied during installation to activate expansion or to verify proper setting. It must be measured with a calibrated torque wrench.

A torque-measuring tool with a current calibration record used to apply and verify installation torque. Its calibration status is a routine inspection checkpoint.

The field check in which a specified torque is reapplied to an installed anchor to confirm it was properly set and has not loosened. Failure to hold torque may indicate a defective installation.

A failure mode in which a cone of concrete around the anchor is pulled out under tension load. Capacity depends on embedment, edge distance, spacing, and concrete strength.

A failure mode in which the anchor withdraws from the hole without a large concrete cone, often due to insufficient embedment, poor hole cleaning, or an undersized expansion element.

A field test in which a specified load below the design capacity is applied to a sample of installed anchors to confirm installation quality and load behavior without causing damage.

Two or more anchors acting together to resist a load, with behavior influenced by the spacing and edge distance between them. Group capacity is not simply the sum of individual capacities.

A documented set of inspection activities, frequencies, acceptance criteria, and records for anchor installation. It defines what the inspector verifies and how nonconformances are handled.

The documented evidence of inspection activities, including dates, locations, observations, test results, and inspector identity. It provides traceability and supports acceptance of the installation.

A stage in the installation process at which work must stop until a required inspection or approval is completed. It prevents concealment of nonconforming work before the next step.

A documented condition in which the installed work does not meet the specified requirements, such as incorrect embedment, missing hole cleaning, or failed torque verification. It requires disposition and corrective action.

The published directions supplied by the anchor manufacturer describing approved drilling, cleaning, setting, torque, and curing. Inspectors verify that field work matches these instructions exactly.

The process of confirming that the anchor delivered to the site matches the specified type, size, length, and approval listing. Mismatched anchors invalidate design assumptions.

The depth of the concrete member measured through the anchor location. It must be sufficient for the embedment depth and to prevent breakthrough or blowout during drilling.

The use of detection equipment to locate reinforcing steel before drilling, so the anchor hole avoids cutting rebar. It reduces structural damage and drilling obstructions.

A field sampling method in which a cylindrical core is cut from the concrete and tested to verify in-place compressive strength. Results may be used to confirm design assumptions.