Racking, guarding, mezzanines and machinery are all held down by anchors that almost nobody verifies after installation. Field proof load testing is quick, it is cheap relative to the consequence, and it is the only way to know what is actually in the slab.
Why installed anchors get tested
Anchor design is a calculation. Anchor performance is an installation. The gap between the two is where the failures live: a hole drilled to the wrong depth, dust left in the bore before an adhesive anchor was set, an expansion anchor tightened past its torque, an anchor placed too close to a slab edge, or a base plate shimmed in a way nobody recorded.
Design is governed by CSA A23.3 Annex D, which sets out the limit states procedure for cast in and post installed anchors in cracked and uncracked concrete. Annex D depends on the anchor having been pre qualified by testing, and on the installation matching the assumptions. Field testing is how the second half of that gets confirmed.
Where we are usually called
Pallet racking. New installations, reconfigurations, and racking that has been struck by a lift truck. Anchorage is assessed alongside the rack itself under CSA A344.
Machine guarding and fencing. Perimeter guarding is only as good as its base fixings, and guard posts are routinely anchored into thin slabs or into cracked concrete near a saw cut.
Mezzanines and platforms. Column base plates, along with the connection detail above them under CSA S16.
Equipment anchorage. Presses, robots, conveyors and dust collectors, particularly where a machine has been relocated and reused an existing bolt pattern.
Post remediation verification. After a deficiency has been corrected, testing closes the file with measured evidence rather than an assurance.
How the test runs
Static tension proof load testing follows the methods in ASTM E488 and the field procedures in ASTM E3121, applied to a sampling plan agreed before we mobilise.
SamplingTypically the first three anchors of each type, size and installer, then a randomised sample of the remainder. The percentage is set by the consequence of failure, not by convenience.
Proof loadThe lesser of the load shown on the drawings, a value from the applicable table, or a defined proportion of the anchor's tension capacity. Agreed in writing before testing begins.
MethodCalibrated hydraulic ram and load cell on a reaction frame, confined or unconfined depending on whether the concrete breakout mode is being assessed.
HoldLoad applied smoothly and held, with displacement measured throughout rather than only at the end.
AcceptanceThe anchor holds the proof load without exceeding the permitted displacement and without any of the failure modes in ASTM E488 occurring.
Torque checkCalibrated torque wrench verification on mechanical anchors, which frequently catches problems before a load test is even needed.
Failure modes we assess
A load test result on its own is not an answer. What matters is which mode governed and whether the design accounted for it.
Steel failure of the anchor element in tension or shear
Concrete breakout, where a cone of concrete lifts. Governed by embedment depth, edge distance and anchor spacing
Pullout of a mechanical anchor without a full breakout cone
Bond failure of an adhesive anchor, which usually traces back to hole cleaning
Side face blowout near a free edge on deeply embedded anchors
Splitting where edge distance, spacing or member thickness is insufficient
Installation inspection
Testing is more useful when the installation record exists. Where we are engaged early we also verify anchor type and dimensions, base material and its age, drill bit type and hole dimensions, hole cleaning procedure, spacing and edge distances, member thickness, effective embedment, tightening torque, adhesive mixing and hole filling, all against the manufacturer's printed instructions and evaluation report.
What you receive
A sealed report with measured loads, displacements and the governing failure mode for each anchor tested
The sampling plan, calibration records and acceptance criteria used
Photographic record of test set up and any anchor that did not pass
Specific corrective recommendations where anchors are found deficient, and re testing after correction
A note on standard references. Anchor testing sits across several documents depending on the application and the specifying authority. We confirm the governing standard and acceptance criteria with you in writing before mobilising, so there is no dispute about the basis of the result afterwards.