Trusted In Situ Density Test Services
At ACS, our accredited field technicians carry out in situ density testing directly on site, supporting construction and environmental projects where accurate ground verification is essential. We work alongside site teams to provide timely, practical testing that helps confirm earthworks are meeting specification and allows decisions to be made without unnecessary delay.
We test a wide range of ground conditions for density and shear strength, including soils, sands, gravels, saturated clays, and silts. Alongside this, we can assess the ground for features that can influence performance, such as voids, pore spaces, disturbance, alteration, oxidation, and intrusions, helping build a clearer understanding of site conditions as work progresses.
Testing and Support for Your Project
We tailor our approach based on ground conditions, access, and project requirements, using a range of established in situ density testing and sampling methods, including:
- Continuous sampling
- Density testing by sand replacement (BS 1377-9)
- Dynamic probing (DPH and DPSH)
- Landfill site testing
- Standard penetration testing (SPT)
- Undisturbed soil sampling (U100)
- Void and buried obstruction locations
- Window and windowless sampling
The Role of In Situ Density of Soils, Sands, and Gravels
In situ density testing confirms whether ground and earthworks have been placed and compacted to the required specification. It provides practical insight into how materials such as soil, sand, and gravel may perform once in use, helping reduce the risk of unexpected movement, delays, or rework later in the project.
ACS provides clear, reliable data to support decisions on site suitability. Our reporting focuses on key performance factors, including bearing capacity, layer stability, settlement, and sub-layer pressure. These results help you confirm that the ground meets project requirements before moving on to the next stage of construction.
Why Choose ACS for In Situ Soil Density Testing?
When earthworks need to be verified on site, you need results that are accurate, consistent, and delivered without slowing progress. At ACS, we combine technical precision with a practical understanding of construction programmes to support informed decisions at each stage of your project.
Trusted Expertise
You’ll benefit from our decades of experience and broad capability across construction, civil engineering, and environmental sectors.
Accredited Testing
We provide a comprehensive UKAS-accredited testing service, both on site and in our laboratory, covering a wide range of materials and ground conditions.
Experienced Technicians
Our teams work safely and efficiently on active sites, following strict quality procedures to deliver reliable data with minimal disruption.
Clear Reporting
You'll receive prompt, clear results that support site decisions and project documentation, helping reduce the risk of costly delays or rework.
Expert Consultancy
Alongside testing, we can advise on suitable test methods and help you interpret results so you can move forward with confidence.
The ACS team is here to support you with in situ density testing and any wider construction materials testing or ground investigations you may need. Get in touch today!
Frequently Asked Questions
What is an in situ density test?
An in situ density test measures how tightly packed the ground is at your specific site. This gives us the most accurate view of how the ground behaves in its natural environment or after it has been compacted by machinery.
What is an in situ soil density test?
An in situ soil density test focuses specifically on the earth beneath your site to verify if it has been compacted enough and won’t shift once construction begins. It’s an essential part of quality control that gives you a clear picture of how the soil will perform once in use.
Why is an in situ dry density test important?
In situ dry density testing determines the soil's true strength by removing the weight of water from the calculation, confirming whether the ground is stable enough to support the weight of the finished project. It identifies hidden gaps or loose soil that could cause the ground to sink or shift, so you can address these issues during construction and avoid the costs of future repairs or delays.
What is the difference between a density test and a dry density test?
A standard density test measures the mass of the soil, including any water it contains. A dry density test removes the water weight to calculate the density of the soil particles alone.
What materials can you test on-site?
We can test a wide variety of materials, including recycled materials, natural soils, sand, gravel, and crushed rock. We also work with more challenging ground types like saturated clays and silts, so you can be sure that no matter what you’re building on, the foundations are secure.
How do you perform a sand replacement test?
The sand replacement method (BS 1377-9) is a common way to measure density. We dig a small hole in the ground and then fill it with a specialised, uniform sand from a calibrated cylinder. By comparing the weight of the sand used to the weight of the soil we removed, we can calculate the exact density of the ground.
How long does it take to get results?
We prioritise a quick turnaround to keep your project on schedule. While the physical testing happens quickly on-site, we often provide preliminary findings immediately, followed by a formal, detailed report once our engineers have verified the data.
Contact us for In Situ Density Testing
Please see below for a list of the services provided by ACS:
Geo-Environmental Consultancy
The ACS Geo-Environmental Consultancy Department has been operating as part of ACS for over 10 years.
On-Site Testing Services
ACS offers a comprehensive range of professional on-site testing, all carried out by our fully trained site technicians.
Aggregates and Soils Testing
From our main laboratory in Poole, Dorset, ACS provide quality testing and material consultancy for the construction and civil engineering industry.
Bituminous Testing
ACS carries out testing on new bituminous binder material and testing on hardened material for physical and chemical properties. Circa pre 1980’s Tar (Carcinogenic effects) was also used as a binder, ACS staff can sample and test materials to assess if Tar was used.
Concrete Testing
Concrete was the first service to be offered by ACS back in 1987. Since then, we have increased our scope to cover a wide range of UKAS Accredited testing methods on fresh and hardened concrete.
Mortar and Screed Testing
ACS can sample and test new and hardened mortar. Hardened mortar for mix proportions and constituents, new mortar for compressive and flexural strength.
Natural Stone Testing
Our newly refurbished stone testing laboratory has given us the opportunity to expand our testing scope. In addition, we have increased production and improved on our turnaround of samples.
Site Laboratory Services
Over the last 35 years, ACS have supplied custom fitted site laboratories with technicians to many construction sites and projects worldwide.