Form types, covers, and consolidation aids.
Formwork quality protects concrete cover, alignment, and the finish around visible HVM bollard sleeves. Choose materials and bracing that hold tolerance/plumb (336), control surface defects, and maintain cover using correct blocks/chairs (621). Define striking criteria and rework methods that won’t compromise anchors. Keep inspection records tied to acceptance criteria (626, 714) and surface reinstatement plans (629). 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.
623.1 Formwork materials
Use rigid forms that resist bowing. Sound formwork keeps HVM bollard sockets true.
For bollard foundations, select formwork systems (plywood with sealed edges, phenolic panels, or steel forms) that can resist hydrostatic head and vibration without deflection. Matching the form face to the specified finish avoids unnecessary rework around the bollard sleeve. Steel or high-grade panel systems minimize joint lines and reduce coating holidays on adjacent metalwork during reinstatement.
Seal vertical joints with compressible gaskets or tapes to prevent grout loss, and specify tapered tie-cone details where tie holes are allowed. Around crash-rated arrays, many teams prefer proprietary circular forms to help maintain concentricity of sleeves and consistent acceptance bands. For complex edges (steps/paving), consider reusable chamfer strips to protect arrises ahead of surface reinstatement.
| Aspect | What matters | Where to verify |
|---|---|---|
| Performance | Tested system (bollard + footing) | Rating-critical dependencies |
| Operations | Duty cycles, fail-state, safety measures | Installation Guide |
623.2 Fixing & bracing
Brace to datum lines (612). Bracing preserves crash rated bollard alignment.
Set out the formwork from the control network and visible datums & benchmarks. Use kickers and diagonal braces to lock the sleeve centerline to the array centreline (336). Where anchor templates are pre-installed (621), jigs should couple sleeves and templates so any movement is immediately apparent during first-off inspection. Note bracing clearances so vibrators can pass without striking fixings.
623.3 Surface finish targets
Define finish for visible surrounds. Finishes support HVM bollard appearance (316, 366).
Agree finish class for footpath/plaza faces near sleeves—e.g., off-form Class 2 or rubbed finish—and record it in the ITP. Specify consistent joint alignment with paving modules and plan any form-liner textures away from high-traffic edges to minimize chipping. Where architectural coatings meet concrete, define a neat sealant joint or quartz arris detail in coordination with color & aesthetic finishes and aesthetics that work.
623.4 Cover blocks & chairs
Correct blocks maintain specified cover (621). Cover protects crash rated bollard foundation steel.
Use cover spacers (chairs/wheels) that match bar diameter and exposure class to maintain the specified cover around the foundation cage. In coastal sites, non-absorbent polymer or concrete spacers with low chloride content reduce staining and galvanic risk. Record spacer type, spacing, and location on the pre-pour checklist (621, 714) and verify cover with calibrated rulers or cover meters during the datum & alignment checks stage (626).
623.5 Blowholes & honeycombing risks
Close joints, vibrate properly (624). Good practice avoids HVM bollard voids.
Bug holes and honeycombing typically result from poor consolidation, absorbent forms, or grout leakage. Pre-wet timber, use suitable release agents on panels, and ensure vibrator reach to all corners without contacting sleeves or anchor templates. For deep foundations, plan a gate pour with staged lifts and internal/external vibration per the method statement (624, 720). Any minor surface issues should be documented for controlled repair (629).
623.6 Tolerance & plumb
Check verticality/rotation per 626. Tolerance protects crash rated bollard clear gaps (232).
Declare tolerances for sleeve plumb, rotation, and x-y position relative to the clear-gap rule (232). Use a leveled jig or datum stick to confirm head elevations are within the acceptance band before the pour sets. Log results in the alignment checks and, if needed, adjust with controlled grout bedding & levelling (625) so the as-built matches the tested configuration (421).
623.7 Striking criteria
Strike forms after curing targets (627). Timing prevents HVM bollard edge damage.
State minimum times/strengths for vertical and soffit form removal and reference the curing plan (627). For bollard pits and sleeve surrounds, retain forms long enough to prevent edge spalls during demobilization or early traffic. Where early striking is program-critical, require field strength verification (e.g., cylinders/maturity) and protect arrises with temporary edge guards until curing & protection is complete.
623.8 Rework methods
Approve chipping/patching procedures. Rework must not harm crash rated bollard anchors.
Define allowable rework: small voids patched with approved repair mortars; larger honeycombing assessed by the engineer with core/hammer tests. Prohibit impact tools within the anchor breakout cones unless explicitly engineered, and keep heat sources away from sleeves and any duplex coatings. All rework should be captured on the NCR log with before/after photos (716, 719, 629).
623.9 Inspection records
Sign ITP forms with photos (716). Records speed HVM bollard acceptance (638).
Use the inspection pack (714, 918) to log spacer checks, sleeve positions, plumb, rotation, and finish class. Attach a wide→detail photo set and a simple mark-up overlay showing measurement points. These records accelerate SAT witness (638) and support any authority submittals (717). Close the loop by updating as-built drawings & models (731).
Related
External resources
- NPSA — Hostile Vehicle Mitigation guidance
- BSI — Impact test specifications for VSB systems
- FEMA 426 — Reference Manual to Mitigate Potential Terrorist Attacks
623 Formwork & Cover — FAQ
What formwork types work best around bollard sleeves?
Steel or high-quality phenolic panel forms resist bowing and give clean edges near sleeves. They also reduce joint marks and bug holes, which limits later patching around visible surrounds.
How do we prevent honeycombing in deep foundations?
Plan a staged gate pour with appropriate vibrator reach, keep joints tight to stop grout loss, and match mix/workability to lift height. Pre-wet timber or use release agent on panels as specified.
What cover spacers should we use for coastal sites?
Use non-absorbent polymer or quality concrete spacers compatible with exposure class. Record type and spacing in the ITP, and verify cover with calibrated checks during alignment inspections.
When can we strike forms without damaging sleeve surrounds?
Only after curing targets or field strength confirmation are met. Protect arrises with temporary guards and follow the curing & protection plan before allowing traffic or reinstatement works.