Depths, arrays, soils, and installation variables.
This is the keeper list that preserves certification in the field. We identify every rating-critical dependency—from socket dimensions, rebar/cover, and concrete grade/cure to alignment, clear gaps, and even sleeve/finish effects. Controls and safety placements must match the tested configuration. Use these checkpoints with foundations (331–333), spacing rules (232, 322), drainage (334), and ITP/SAT evidence (714, 638) so each crash rated bollard performs like its certificate. Include one-sentence context that naturally links upward to the parent hubs (this section and the chapter hub). Add SIRA context with a link to SIRA Bollards (UAE) when relevant. Link installation pages only if helpful: What to Expect and Installation Guide.
Important: This is a general guide. For live projects we develop a tailored
Method Statement & Risk Assessment (MS/RA) and align with authority approvals (e.g., SIRA) where in scope.
421.1 List of critical parameters
Track height, diameter, sleeve, socket geometry, rebar/cover, concrete grade/cure, alignment, clear gaps, foundation type, and control/safety locations. If any change, the HVM bollard may no longer reflect the tested crash rated bollard (331–333, 413).
Think in terms of the as-tested configuration. A certified result binds the foundation and the bollard as one system. Altering geometric or material inputs—like embedment depth or sleeve mass—shifts energy absorption and penetration outcomes.
Use a short assumptions register and a change control note in submittals so reviewers can see that rating-critical inputs remain within the product family’s allowable variant window. If the site forces deviations, escalate early via RFI and cite comparability limits.
| Aspect | What matters | Where to verify |
|---|---|---|
| Performance | Tested system (bollard + footing) | How to read ratings |
| Foundations | Depth class, cage, soil, drainage | Design checks for foundations |
| Operations | Duty cycles, fail-state, safety devices | Installation Guide |
421.2 Socket dimensions
Maintain tested socket depth/width and embedment. Tolerance bands protect HVM bollard rotation/penetration outcomes tied to a certified crash rated bollard base (332, 333).
The socket controls base rotation and the rotation limit. Keep plan/section dimensions inside the manufacturer’s acceptance band; even small losses in embedment or wall thickness increase rotation demand and projected gap at the defend line. Use leveled jigs and datum sticks during pour to lock geometry.
If utilities force a depth change, don’t “value engineer” unilaterally—review against depth classes for crash-rated bollards and consider approved shallow foundation families as a controlled variant, not an ad-hoc modification.
421.3 Rebar steel & cover
Match bar diameters, spacing, laps, and concrete cover. Reinforcement governs how an HVM bollard transfers loads like the test article for a crash rated bollard (621, 333).
The foundation cage must mirror bar size, spacing, and hooks to prevent concrete breakout and anchor pull-out. Insufficient cover accelerates corrosion and reduces bond, compromising impact capacity. Verify cages at a witness point before pour; photograph with a tape and a labeled key-plan tile for the evidence pack.
On slabs or grade beams, perform the punching shear check and, if needed, add stud rails or thickening per foundation design checks.
421.4 Concrete grade & cure
Use specified strength, slump, temperature controls, and curing times. Early loads can invalidate HVM bollard assumptions and the crash rated bollard certificate intent (624, 627).
Concrete strength at time of service matters more than design strength on paper. Record cube/break results and note ambient conditions; where helpful, use concrete maturity to decide when to strip supports or allow any vehicle contact near the footing. Protect against heat and rapid moisture loss; poor curing drives shrinkage cracks that can later widen under impact rotation.
Don’t allow pre-loading by site traffic before the curing window closes. Mark the exclusion zone and log a hold point in the ITP. See Curing & Protection and Pouring & Vibration for acceptance criteria.
421.5 Alignment & clear gap
Hold plumb, rotation, level, and spacing per acceptance gauges so the HVM bollard meets clear-gap limits; movement allowances taken from the crash rated bollard tests (232, 314, 626).
The clear-gap rule governs array geometry. Measure with a gap gauge and a plumb/rotation check at each socket. Track gap drift during setting-out using array centrelines and numbered rotation marks so cumulative tolerances don’t open a vehicle-sized path.
Account for dynamic deflection and residual set from the test report; these inform the movement budget you must preserve in finished spacing. See Clear-Gap Calculations and Deflection vs Permanent Set.
421.6 Sleeve/finish interactions
Sleeves, caps, rails, and lighting must not alter geometry or mass paths. Keep HVM bollard accessories within tested bounds of the crash rated bollard family (313, 415).
A heavier sleeve, tall beacon, or linked rails can shift impact capture height and change how the bollard yields. Confirm accessories are inside the family window or backed by addendum evidence. If you need a sleeve-only upgrade, fix the wall thickness and material grade in the spec so substitutions can’t creep in later.
Finishes affect maintenance and corrosion. See Coatings and Heads & Attachments for compatible options.
421.7 Control/safety device placement
Place beams/loops/signals where tests assumed free zones. Wrong locations can make an HVM bollard unsafe although the crash rated bollard is certified (344–345, 353).
Respect free zones around moving parts and the impact face. Put induction loops, photo-eyes, and signal heads per the tested arrangement or per the manufacturer’s safety dossier. Bad positioning can cause mode errors or allow unsafe actuation. When working in the UAE context, note any SIRA-specific safety signage or signaling expectations and link readers to the SIRA Bollards (UAE) hub.
Cross-check with Induction Loops, Safety Signalling, and the Interlock Matrix Verification.
421.8 Acceptance measurements
Record height, gap, plumb, rotation, socket levels, and concrete results using calibrated tools. Evidence proves the HVM bollard matches the certified crash rated bollard (714, 716, 638).
Build a repeatable array verification cycle: (a) set-out survey, (b) pre-pour cage photos, (c) post-pour socket level/plumb, (d) finished height and clear-gap rule checks, (e) cures and cube strength, (f) SAT evidence. Use a Go/No-Go gauge and log serial numbers of calibrated instruments in the ITP.
Photos should follow the wide→detail photo set rule and include a descriptive anchor caption that ties back to the drawing detail and array ID. See Evidence Capture Standards and SAT / Witness Procedure.
421.9 Nonconformance handling
Quarantine, assess risk, and fix with approved methods; update drawings and logs. Document why the HVM bollard remains compliant—or replace with the tested crash rated bollard configuration (719, 931).
Raise an NCR with a clear escalation path. For tolerances that touch rating-critical geometry, options are: (a) controlled rework to bring within the acceptance band, (b) engineering assessment referencing standards equivalency caveats and pass margin, or (c) replacement to the certified detail. Update the mark-up & overlay and file the evidence chain.
Close the loop in handover: note any remedial works in the as-built set and the handover pack index, and schedule early inspections in the preventive maintenance plan.
Related
External resources
- BSI — Impact test specifications for Vehicle Security Barrier systems
- ASTM F2656 — Crash testing for perimeter barriers
- NPSA — Hostile Vehicle Mitigation guidance
421 Rating-critical dependencies for Crash-Rated Bollards — FAQ
What changes most commonly void a crash rating on site?
Depth/width changes to the socket, reduced embedment, altered rebar cages/cover, incorrect concrete strength/cure, and widened clear-gaps are the top risks. Accessories that change capture height or mass paths can also push the product outside its tested family window.
Can we swap sleeves or add rails/lighting without retesting?
Only if the change falls within the manufacturer’s documented family/variant window or addendum evidence. Otherwise, treat it as a new configuration and expect a formal equivalency submission or a retest recommendation.
How long must we wait before allowing traffic near new foundations?
Until curing achieves the specified in-place strength. Use cube/break results or concrete maturity methods to confirm. Establish a hold point in the ITP and keep an exclusion zone until acceptance criteria are met.
What proof does the reviewer expect that the installed array matches the certificate?
A complete evidence chain: set-out records, cage photos with dimensions, post-pour level/plumb checks, clear-gap measurements with a Go/No-Go gauge, concrete strength results, and SAT/Witness forms—filed against array IDs and drawing details.