At Simtec, our experienced technicians deliver a comprehensive range of Pavement Investigation Services, designed to assess the construction, performance, and condition of the UK's roads and highways.
We focus on minimising disruption while providing safe, efficient, and tailored procedures for every project.
What Are Pavement Investigations?
The UK's road network is constantly under pressure, requiring regular maintenance, rehabilitation, and improvement to remain safe and efficient.
A pavement investigation provides essential insight into a road’s construction and current condition, helping asset owners and engineers make informed decisions on future maintenance and investment.
Working closely with contractors, consultants, local authorities, and government agencies, Simtec provides skilled technical teams and specialist equipment, available for both daytime and nighttime working to carry out complex pavement investigations across the country.
Our Pavement Investigation Services
With extensive experience across flexible, rigid, and composite pavement types, Simtec delivers a full suite of pavement investigation services. Our teams carry out a range of surveys, coring, sampling, and testing methods to determine pavement structure, identify defects, and support long-term maintenance planning.
Early project engagement allows us to develop a bespoke testing and reporting strategy that aligns with each client's needs.
Findings from on-site investigations and laboratory analysis are then used to assess pavement condition and help shape future maintenance strategies.
Our pavement investigation services include:
- Pavement coring and construction layer logging
- Topographical and level surveys
- Carriageway, footway, and verge trial pit excavation, logging, and reinstatement
- Dynamic Cone Penetrometer (DCP) testing (% CBR test value)
- Bridge joint pencil core sampling and logging
- Waste Acceptance Criteria (WAC) analysis
- Bridge waterproofing investigations
- NRSWA-qualified operatives and supervisors
- Unbound Material Sampling (UMS)
- Materials sampling and testing to support Highways S278 design submission, Section 184 application
- Large diameter access coring
- Trial pit logging
- Lightweight deflectometer (LWD)
- Tar-bound material (coal tar) sampling and analysis
- Laboratory testing for geotechnical, chemical, and environmental properties
- Traffic Management Support
FWD Pavement Testing
For projects requiring a deeper understanding of pavement structural performance, Simtec also offers specialist Falling Weight Deflectometer (FWD) testing. This advanced, non-intrusive technique measures pavement deflection under simulated traffic loading, providing valuable insight into structural capacity, residual life, and maintenance needs. Our
FWD testing services support data-led asset management and long-term planning.
Find out more about our FWD Pavement Testing services
Core Sampling & Diamond Coring Services
As part of our pavement investigation offering, Simtec provides specialist core sampling and diamond coring to accurately assess pavement layers, construction quality, and material performance.
Using modern hydraulic drilling equipment and high-grade diamond-tipped core barrels, our NRSWA-qualified technicians extract clean and precise samples from asphalt, concrete, and composite pavements. Reinstatement is completed to a high standard using approved materials to ensure durability and safety.
Core sample analysis may include:
- Logging and photographic records of extracted cores
- Bulk, Maximum density testing and air voids
- Indirect Tensile Stiffness Modulus (ITSM) and Cyclic compression test
- Binder content and aggregate grading
- Bitumen recovery
- Needle penetration and softening point
- Tar content analysis (including identification of coal tar)
- Thickness Measurement
Coring is a routine part of Simtec’s pavement evaluation work, and many clients rely on our expertise to verify pavement thickness, compaction quality, and material performance. We are known for the high standard of our reinstatement, ensuring core holes are restored using prime materials that blend seamlessly into the surrounding surface.
Whether a single core or a large-scale coring programme is required, Simtec provides an efficient, reliable, and competitively priced service — with no minimum charge.
Pavement Investigation Experience and Standards
Working nationwide, our technicians and engineers are fully trained under the New Roads and Street Works Act (NRSWA) and follow strict safety and traffic management procedures to minimise disruption during investigations.
In addition to pavement investigations, Simtec also provides:
- Bridge and Infrastructure Surveys
- Building Fabric Surveys and Structural Assessments
- Post Tension and Prestressed Investigations
- Assurance and Compliance Testing
- Technical support, including Specification writing
- Factual and interpretative reports
All pavement and material samples are processed in our in-house laboratory, which operates to recognised quality standards to ensure accurate and reliable test results.
Why Choose Simtec for Pavement Investigations?
At Simtec, we combine technical expertise, advanced equipment, and a client-focused approach to deliver high-quality pavement assessments.
Every project benefits from a tailored investigation strategy designed to meet the demands of challenging working environments, from busy highways to sensitive urban areas.
Our services help clients:
- Identify structural defects early
- Plan targeted and cost-effective maintenance
- Improve road safety and reliability
- Extend pavement service life
FAQs for Pavement Investigation Services
What is included in a pavement investigation and how do I know which tests I need?
A pavement investigation checks how a road is built and how well it’s performing so engineers can decide whether to maintain, strengthen, or rebuild it. It normally includes site work plus laboratory testing.
1. Site investigation & sampling
Pavement cores
- Show layer thicknesses, material types, and condition.
- Help check bonding between layers and air voids/density.
Trial pits
- Expose the sub-base and subgrade to look at drainage, formation level, and any weak layers.
Dynamic Cone Penetrometer (DCP)
- Measures in-situ strength and helps estimate CBR, useful where records are limited or failure is suspected.
Optional in-situ tests
- LWD / plate bearing for local strength.
- FWD for structural capacity and overlay design.
2. Laboratory testing (from samples)
Asphalt – binder content, grading, density/voids, stiffness, ITS
→ Used to judge condition, recycling potential, and overlay design.
Unbound materials – grading, moisture, CBR (DCP), sulphate/pH
→ Confirms sub-base quality and flags contamination.
Subgrade soils – moisture, Atterberg limits, CBR, classification
→ Critical for reconstruction or major strengthening.
3. How do you know which tests you need?
Start with the purpose of the scheme:
- Minor maintenance / resurfacing
Cores + visual survey; limited asphalt tests. Deep trial pits are usually not needed. - Structural overlay design
Cores, DCP for CBR, asphalt stiffness, and subgrade strength. - Full reconstruction
Trial pits to formation, subgrade sampling, sulphate and classification testing. - Early failure investigation
Detailed asphalt tests, bonding checks, and compliance review.
How disruptive is pavement investigation work and what traffic management is required?
Pavement investigation work is generally only mildly to moderately disruptive, especially when compared with major maintenance or reconstruction. The level of disruption and traffic management (TM) required depends on the investigation method, road type, and traffic volumes.
Moderate disruption examples include Pavement coring, Dynamic Cone Penetrometer (DCP) testing, small trial pits, requiring temporary lane closures or stop/go control, Short-term noise and vibration, localised delays, especially on single carriageways, full road closures or night-time working, and Temporary reinstatement of core holes required.
What traffic management is required? Urban / low-speed roads, Advance warning signs, Cones and barriers, Temporary traffic lights or stop/go boards, Pedestrian management where footways are affected, Rural single carriageways, Stop/go boards or temporary signals, Careful management of queue lengths, Traffic marshals where visibility is limited, High-speed roads (dual carriageways, trunk roads, motorways), Lane closures designed to standards, Taper lengths, safety zones and crash cushions, Traffic management vehicles (TMVs), Often restricted to off-peak or night-time working.
How disruption is minimised: Use of non-destructive testing first, limiting the number of cores or pits, Short duration works and rapid reinstatement, Off-peak or overnight working, combining investigations into one visit.
In summary: Pavement investigations are usually short-term and localised; Traffic management is proportionate to the risk and road type; and disruption is significantly lower than for full maintenance works.
How are pavement core samples taken and what information can they provide?
Step 1: Planning and location selection: Core locations are chosen to represent Wheel paths, Areas of distress (cracking, rutting, fretting), and Uniform sections of pavement. Locations are risk-assessed and coordinated with traffic management plans. Utilities searches are undertaken before drilling.
Step 2: Traffic management: Depends on road type: Urban roads: cones, signs, stop/go or temporary signals, Single carriageways: stop/go boards or signals, Dual carriageways/trunk roads: lane closures, TM vehicles, off-peak or night works, TM is designed to UK safety standards.
Step 3: Coring process: A diamond-tipped rotary coring rig is used. Typical core diameters:100 mm (most common)150 mm (where greater detail is needed), Water is used to cool the drill and suppress dust. Coring usually penetrates: The full bituminous pavement thickness, sometimes into the top of the foundation layer. The core is carefully extracted intact and labelled.
Step 4: Making safe and reinstatement: The core hole is cleaned and dried, refilled with hot-lay or cold-lay bituminous material, and the Surface is compacted and sealed to prevent water ingress. Reinstatement is temporary or permanent, depending on the scheme.
What information do pavement cores provide?
Pavement cores provide direct, high-confidence evidence about how a road is built and how it is performing. By drilling small samples through the surface, engineers can accurately measure each layer's thickness, identify material types and mix (e.g., HRA, SMA, DBM), and assess condition issues such as debonding, cracking, ageing, segregation, moisture damage, or water ingress. Laboratory testing of the cores can then confirm density, air voids, binder content, stiffness, and tensile strength, and help validate other surveys like GPR or FWD. Although each core represents only a small point and requires traffic management and reinstatement, the information gained is critical for verifying records, supporting pavement design, and selecting the right maintenance or strengthening strategy.
How long does a pavement investigation take and when will results be available?
A pavement investigation is usually quick on-site, but full results take longer because samples need laboratory testing and professional interpretation. Small coring jobs (5–10 cores) can often be completed in half a day, while investigations with trial pits or DCP testing may take 1–3 days, with larger schemes phased over several days and managed using local lane closures. Basic information such as layer thicknesses and visible condition is often available the same day, while lab results for density, voids, binder content, and stiffness typically take 3–7 working days (and up to 1–3 weeks for more detailed tests). Once results are combined with other data (e.g., FWD or GPR) and assessed by a pavement engineer, most small schemes receive a final report within 1–2 weeks, medium schemes in 2–3 weeks, and larger or complex projects in 3–6 weeks, allowing for any traffic, weather, or lab-related delays.