Comprehensive Airside Joint Sealing and Concrete Pavement Repairs

Introduction

Jointline’s Civils and Maintenance division was appointed by Northstone Materials to carry out a major programme of airfield maintenance at RAF Aldergrove Flying Station, a key operational facility within the UK Defence Infrastructure Organisation (DIO) estate. The works formed part of a wider initiative to ensure the longevity, safety, and resilience of the airside pavement infrastructure supporting critical military flight operations.

The scope of Jointline's contract encompassed the cutting and resealing of over 42,000 linear metres of existing pavement joints, together with full-depth concrete repairs and precision crack cutting. The works were carried out in multiple phases between June and November 2025 and covered key operational zones including Stands 9 and 11, Echo Taxiway, DA2 Apron, Taxiways Foxtrot and Juliet, the Eastern Dispersal area, and Helicopter Dispersal areas.

Executed under strict security and airfield safety protocols, the project required high-level coordination with other contractors and base operations staff. All repair activities were completed to aviation specifications using durable, fuel-resistant materials approved for MOD airfields.

The Challenge

The project presented a number of technical and logistical challenges that required detailed planning, adaptive phasing, and strong stakeholder collaboration.

1. Live Operational Environment

RAF Aldergrove is an active military airbase with ongoing flight schedules, aircraft movements, and critical mission support services operating around the clock. To accommodate this, Jointline worked alongside Northstone to develop a meticulously phased delivery programme. Each section of work was coordinated around flight windows, ensuring that operational access routes, apron areas, and dispersals remained available as required. Stand access was tightly controlled, and all working areas were established and dismantled daily to ensure compliance with security and safety protocols.

2. Inclement Weather Conditions

Throughout the project period, Jointline’s crews faced periods of adverse weather, including frequent rainfall and variable temperatures. These environmental conditions posed challenges for joint resealing and concrete curing times. To mitigate these risks, the team implemented weather monitoring procedures, adjusted schedules dynamically, and used fast-setting, moisture-tolerant repair materials where required. Temporary protection measures such as polyethylene sheeting and tented areas were used in sensitive zones to ensure cure integrity.

3. Programme Integration

The project was delivered under a broader airfield improvement framework led by Northstone Materials. Jointline collaborated closely with the principal contractor and associated workstreams to ensure programme integration across all disciplines. Interfaces with civil engineering, surfacing, and electrical teams were actively managed through shared sequencing models and constraint-based planning. Regular coordination meetings and real-time reporting protocols facilitated synchronised delivery, minimising disruption and ensuring compliance with the critical path schedule.

4. Technical Precision and Compliance

All repair activities were required to meet stringent technical standards for military aviation infrastructure. This included precise execution of joint dimensions, sealant depths, patch geometry, and surface tolerances. QA procedures were implemented throughout, including pre-pour inspections, slump testing, and post-repair joint integrity checks to ensure a fully compliant outcome.

The Solution

Jointline deployed its airfield-specialist teams with extensive experience in military aviation environments. Key elements of the solution included:

Joint Sealing and Resealing

• Over 42,000 linear metres of existing joints were cut out using mechanical floor saws and gritblasting techniques.
• Debris was removed by sweepers and air blowers to ensure a clean profile and prevent FOD issues
• Joints were primed with Thioflex 7E Primer, and new sealant was installed using heated pump systems to apply Thioflex 555 to precise depth and profile specifications.
• SOMIC 16mm cord was used for joint backing, and expansion properties were verified before installation.

Concrete Repairs (Phased Delivery)

Jointline delivered over 120 discrete concrete repairs across three phases:

• Phase 1 included 31 concrete patches (2.295m²) and 13 crack cuts (22.2m), targeting critical areas across Stands 9 & 11, Eastern Dispersal, and adjacent taxiways.
• Phase 2 involved 16 repairs (approx. 1.0m²), focused on mid-depth delamination and surface erosion zones.
• Phase 3 addressed 77 defects including deep slab cracks, edge spalls, and thermal stress damage. Repairs included full breakout, formwork, and reinstatement using aviation-grade concrete (1 : 1 : 2 mix with air entrainment).

All patches were saw cut and dowelled as necessary, with tie bars installed to ensure load transfer integrity. Fast-setting cementitious products and Nitomortar S were used in smaller repairs, with QA sign-off required before handover.

Crack Cuts and Control Joint Additions

• Over 30 linear metres of crack cuts were installed to relieve structural tension.
• Cuts were made using 10mm blades, cleaned by air pressure, and sealed using compatible materials.
• This helped prevent uncontrolled cracking propagation in areas showing thermal expansion stresses.

Surface Line Marking

• Jointline’s specialist airfield line marking division removed existing degraded markings via hydroblasting.
• Replacement lines were applied using chlorinated rubber aviation paint, including taxiway designators, apron edge lines, lead-in lines, and holding positions.
• Works were aligned with CAA CAP168 and NATO standards for military markings.

The Benefits

The completed works have provided RAF Aldergrove Flying Station with long-lasting benefits across safety, compliance, and operational efficiency:

• Improved Pavement Integrity: By resealing over 42km of joints and addressing all known cracking and delamination defects, the airfield's pavements are now protected against FOD risks, water ingress, and freeze-thaw damage.
• Operational Continuity: All works were phased to avoid disruption to military air operations. Coordination with base command and flight control allowed uninterrupted access to priority stands and taxiways.
• Regulatory Compliance: All repairs and marking works meet the stringent criteria outlined in MOD and CAA aviation infrastructure standards.
• Lifecycle Cost Reduction: The use of durable, aviation-grade repair materials and high-quality joint resealing has significantly extended the lifespan of the concrete pavement infrastructure, reducing future reactive maintenance costs.
• Proven Delivery: Despite weather delays and operational complexity, Jointline successfully completed all works on time, within budget, and to the satisfaction of the client and stakeholders.