Client: Local Authority (UK)
Location: Dorset
Services: In situ asphalt testing, bituminous laboratory analysis, traffic management, consultancy
ACS worked with a local authority on early-stage highway investigation to identify the causes of pavement failure and provide reliable data for design and maintenance decisions. By combining in situ asphalt coring with UKAS-accredited laboratory testing, the project delivered clear, actionable results while minimising disruption on site.
Project Background
The local authority in Dorset required a clear understanding of why failures were occurring within an existing highway. Early data was needed to allow highway design work and Hydraulically Bound Material (HBM) trial mix designs to move forward with confidence.
Testing and analysis were specified in line with TRL 611, a recognised guidance document used to assess pavement construction and condition. This ensured that all findings could be directly applied to design, remediation, and long-term maintenance planning.
Project Objectives
The project focused on gathering accurate, representative data from the live carriageway and supporting it with laboratory analysis. Key objectives included:
- Identifying the underlying causes of highway pavement failure
- Measuring foundation strength through in situ testing
- Recovering asphalt samples for potential contamination testing
- Collecting sub-base material to support laboratory trial mixes for in situ stabilisation
- Minimising disruption to road users while maintaining safe working conditions
Our Approach
In Situ Asphalt Coring
ACS carried out in situ asphalt testing using 350mm diameter cores, selected in preference to traditional breakout trial pits. This approach:
- Reduced cutting time on site
- Produced high-quality, representative samples
- Allowed for faster and more durable reinstatement of the carriageway
Due to the size and weight of the cores, ACS introduced updated site procedures to ensure safe handling and lifting, protecting both operatives and the integrity of the samples.
Laboratory Analysis
All recovered materials were tested in ACS’s UKAS-accredited laboratories, ensuring consistent, reliable results that met British and European standards. Laboratory testing supported both failure investigation and the development of trial mixes for future stabilisation works.
Typical bituminous laboratory tests included:
- Asphalt , Sub Base and Sub Grade logs with photographs
- PAK Marker checks
- Coal Tar analysis on PAK positive layers
- Binder content and Mineral Grading
- Bulk density
- Air voids content
Traffic Management & Site Coordination
The works took place on a narrow road with limited space, requiring careful planning to maintain safety and access. ACS managed:
- Road space bookings
- Traffic management design and implementation
- Coordination of third-party contractors
By overseeing these elements from the outset, ACS ensured a smooth workflow on site and reduced the administrative burden on the client.
Challenges & Solutions
Challenge: Recovering large-diameter asphalt cores safely and efficiently.
Solution: New lifting and handling procedures were introduced, supported by trained operatives and clear method statements.
Challenge: Working within a constrained highway environment.
Solution: Traffic management was planned and delivered by ACS, allowing testing to proceed safely with minimal disruption.
Results & Outcomes
The combined in situ and laboratory testing programme provided the client with a clear understanding of pavement condition and failure mechanisms. This allowed:
- Early highway design activities to proceed with confidence
- Trial mix designs for stabilisation works to be developed using representative data
- Informed decisions on maintenance and remediation strategies
Bituminous Testing Services from ACS
ACS provides a comprehensive range of Bituminous Testing Services, delivered both on-site and in the laboratory. All testing is carried out by highly trained technicians holding current CSCS cards and working in accordance with approved risk assessments and method statements.
If you require support with highway investigation, asphalt coring, or laboratory analysis, our team can tailor a testing programme to suit your project requirements.
