Britpave: The British In-Situ Concrete Paving Association

Frequently Asked Questions

Q: I have a site which needs treating - who do I contact in order to get the job done ?

Q: What additional testing should I include in my Site Investigation to determine whether soil stabilisation is suitable for my site ?

Q: What type of soils is it possible to treat?

Q: What size sites are economical to treat?

Q: My site is in a built up area. Will I be able to use stabilisation or is it dusty?

Q: Can I grow plants near stabilised soil?

Q: Will lime have any affect on the environment?

Q: Are naturally occurring sulfates a problem when stabilising soils?

Q: How does REACH affect soil stabilisation?


Q: I have a site which needs treating - who do I contact in order to get the job done ?
A: A good place to start is the Find a Member page on the Britpave website. The page contains listings of Contractors, Consultants and Product and Equipment Suppliers. A phone call or email to one or more of the listed Contractors will allow them to turn your site requirements into a finished job specification and a budget price. Those members who have signed up to the Britpave Guidelines for Best Practice are identified. Best Practice members will work to The Britpave Guidelines, which give significant advantages in terms of the project outcome. For further information regarding Best Practice, please refer to the “Soil Stabilisation Guidelines for Best Practice” publication (available to download from the Soil Stabilisation INFORMATION SECTION under PUBLICATIONS).

Q: What additional testing should I include in my Site Investigation to determine whether soil stabilisation is suitable for my site ?
A: Full details of soil suitability testing are available in the Design Manual for Roads and Bridges Volume 4, HA 74/07. It is important that specific testing for sulfate and sulfide is undertaken. For more information refer to Britpave publication BP/16 - Stabilisation of Sulfate Bearing Soils (available to download from the Soil Stabilisation INFORMATION SECTION under PUBLICATIONS).

Q: What type of soils is it possible to treat?
A: Virtually all soils can be treated to significantly improve their properties. According to the type of soil, the stabilisation contractor will determine the additives needed. Lime is normally used for wet and cohesive soils and cement for granular soils. Quite often these additives are used in combination but Fly Ash and Ground Granulated Blastfurnace Slag are also used. Contact should be made with the specialists on the contacts page for more detail.

Q: What size sites are economical to treat?
A: With the increased costs of disposal, Soil Stabilisation is a very attractive way of treating unsuitable soils. A variety of machines are available for large and small sites and contractors also vary in the size of contract they prefer to undertake. As long as there are brief details of the site soil conditions an order of cost estimate can be provided by one of the Britpave members. Comparisons with alternative options can then be made.

Q: My site is in a built up area. Will I be able to use stabilisation or is it dusty?
A: Special machinery is now being used by the stabilisation contractors that makes the process virtually dust free. There is no reason why soil stabilisation cannot be carried out in urban areas as there is no more disruption than with other construction activities.

Q: Can I grow plants near stabilised soil?
A: Stabilised soil will not normally sustain plant growth as it is not a satisfactory growing medium. An adequate depth of top soil is required and this can be contained within islands cut in the stabilised soil. Stabilised soil is densely compacted and is highly impermeable so adequate drainage needs to be provided for satisfactory plant growth.

Q: Will lime have any affect on the environment?
A: Calcium products used for soil stabilisation are highly insoluble and are contained within a dense and impermeable mass of soil. There is generally no impact on the surrounding environment where soil stabilisation has been carried and water courses have not been affected in the past.

Q: Are naturally occurring sulfates a problem when stabilising soils?
A: Soils that contain naturally occurring sulfate can suffer a swelling reaction if lime is added. This is dependent on the type of soil and the concentration of sulfates present. Tests for sulfates are always carried out by the specialist contractor to determine if special measures are required before any site work is undertaken. Ground granulated blastfurnace slag has been shown to reduce this swelling reaction and has been used successfully on many jobs. Guidance on this treatment technique is given in Britpave publication BP/16, ‘Stabilisation of Sulfate-Bearing Soils’ (available to download from the Soil Stabilisation INFORMATION SECTION under PUBLICATIONS).

Q: How does REACH affect soil stabilisation?
A: The process of soil stabilisation is exempt from REACH. For further information please click here to read the Soil Stabilisation Task Group statement on REACH(available to download from the Soil Stabilisation INFORMATION SECTION under TECHNICAL).