Using SUREGROUND™ original soil properties can be returned through the use of a reagent.
Stone is lifted from the surface and donated to the landowner or main contractor for reuse. The enhanced soil is broken up and a reagent introduced before soils are conditioned to a healthy tilth with a tillage. Seeding is then undertaken, or a landowner can plant crops at their convenience.
The entire process is overseen by a UKAS accredited laboratory. Soil properties are recorded prior to and post stabilisation allowing them to understand the formulation and addition rate of reagent required. The soil is then rotovated with reagent using a dust free system before testing validates that pH and nutrients have returned to their original DEFRA indices.
Soil Science has an expert agricultural team who are available to contractors in land agent and landowner discussions. They can allay any concerns the landowner may have prior to construction.
The FAQ’s below are designed to offer initial comfort prior to specific conversations and meetings with landowners or land agents.
1. What is SUREGROUND™ Reversible Soil Enhancement?
The SUREGROUND™ Reversible Soil Enhancement System is not traditional soil stabilisation. Soil Science is the sole supplier of the only viable Reversible Soil Enhancement solution for temporary works, SUREGROUND™
A binder, bespoke to site soils is introduced, modifying their structural and load bearing properties for use as a stable work platform. The addition of a reagent after works are completed swiftly returns pH and Nutrient to the DEFRA indices of the original soils, providing the ideal conditions required for full regrowth of grasses and/or crops.
2. What does it replace?
Traditional Stone Designs
Traditional stone designs require significant quantities of aggregate and the associated vehicle movements to install. This causes traffic congestion and disruption within the locality where the works are being undertaken. There is further disruption throughout the programme as maintenance is required to this design.
The use of limestone can leach lime content into soils causing irreversible damage. Natural compaction of stone over time causes harmful hard panning to occur in subsoils.
Geosynthetic materials such as geotextile or geogrid must be laid in the subbase for stone to be placed and compacted. Upon reinstatement this is hard to successfully remove, causing extended disruption, risking residual pieces of plastics in subbase soils; this material must also be sent to landfill.
The significant amount of plant and processes adversely affects health and safety, ultimately extending the works duration and lengthening disruption.
Trackway solutions laid out across topsoil compacts and damages these soils affecting their ability to hold crops and grasses. Trackway cannot achieve the necessary load bearing required to undertake most works and is often not a viable solution for construction. 24-hour security is also required to avoid costly theft.
Lime & Cement Stabilisation
Traditional stabilisation methods are not viably reversible as the nutrient and pH values are raised to such a level that a return to original values upon completion of works is very difficult to achieve. This is further complicated by the high addition rate of lime that is required to stabilise material. Lime is caustic and harmful to soils. Lime & Cement stabilisation is not a viable solution for temporary works where soils need to be returned to optimum yield levels.
3. How many vehicle movements will be saved in the construction?
The use of SUREGROUND™ will give a reduction in vehicle movements of 75%, considerably reducing the disruption to the local community.
4. What programme reduction does the use of SUREGROUND™ offer?
The use of SUREGROUND™ will reduce the programme of works by over 50%, significantly lowering the period of disruption to landowners and the local community.
A maintenance free solution will also mean that further aggregate deliveries required to maintain the constructed areas are not needed. This further reduces vehicle movements and congestion after the SUREGROUND™ construction works have been completed.
5. Will there be any residual plastic such as geosynthetic materials?
Traditional stone designs require geosynthetic materials which are hard to remove during the restoration process and are often left within soils, this has an adverse effect on the local ecosystem causing long term issues.
SUREGROUND™ does not require the use of any plastic geosynthetic materials such as geogrids or geotextiles.
6. Does hard panning occur?
Hard panning does not occur with the SUREGROUND™ Reversible Soil Enhancement System. The 350mm stabilised layer acts as one solid platform with minimal flex.
7. What is SUREGROUND™?
SUREGROUND™ represents a range of cementitious binder formulations used for soil enhancement. Its compositions have been developed to allow enhanced soil to be returned to the native soil’s nutrient status using specific reagents that reverse the enhancement process. Once restoration has taken place and pH reversion is complete, the regenerated soil horizon is practically indistinguishable from the geochemical composition of natural soils, prior to the enhancement and restoration process having taken place.
SUREGROUND™ binders are specifically developed admixtures of cement clinker and naturally occurring mineral phases, that are processed to confer specific properties when hydrated. The hydration reactions produce the desirable characteristics specific to the SUREGROUND™ product, forming phases that increase workability during the construction phase and enable reversion during restoration.
8. What are the differences between SUREGROUND™ Reversible Soil Enhancement and Lime/Cement Stabilisation? (Traditional techniques)
Soil Science have a range of reversible cementitious binders that typically achieve equivalent strength gain to cement systems at lower alkalinity. One of the major benefits over cement stabilisation is the prolonged workability period afforded by SUREGROUND™ which provides greatly increased flexibility during the construction phase.
The ability to restore soils enhanced by SUREGROUND™ and return soils back to their original nutrient status is a unique and major benefit of this system.
Lime stabilisation requires aluminosilicate minerals to be present in the soil matrix to react with CaO and produce Calcium AluminoSilicate Hydrate (CASH) gels to form pozzolans with slower longer term strength gain (weeks – months), the use of SUREGROUND™ is not limited to soil types and provides rapid strength development within 24-48 hours. In respect of pH, lime stabilisation requires sufficient lime to produce a stable pH 12.4 (equilibrium pH created by portlandite) whereas SUREGROUND™ operates at considerably lower pH.
9. Is there any lime used in the construction process?
No, Soil Science and SUREGROUND™ does not use lime.
10. How high are pH levels raised during the construction process?
Final pH levels in the enhanced soils are a function of the binder addition rate (determined by the requisite design strength) and native soil mineralogy. For strength gain reactions to occur within the enhanced soil matrix, pH conditions between pH 10-11 must be established, which are considerably lower than the pH conditions created by lime and cement stabilisation.
11. What other nutrient levels (or values) are affected by the construction process?
The reversion of pH levels back to natural soil pH prior to construction phase activities allows readjustment of nutrient levels back to equivalent native soil conditions. Specifically, the restoration process validates the modification of soil nutrient levels following restoration based on DEFRA indices for; available phosphate, available potassium and available magnesium. Other parameters that are analysed for information purposes, not used specifically for the derivation of DEFRA indices and assessment of nutrient status, include; nitrogen as nitrate and ammoniacal N.
12. Are the changes in soil contained within the enhanced areas?
Yes, the low permeability matrix created during the construction phase retards leachability, a property that is often exploited in contaminated land remediation. Furthermore, the physical construction of drainage ditches on the perimeter of enhanced layers acts as an interceptor to capture any potentially alkaline runoff from the enhanced soil during rainfall events.
13. What plant is used to rotovate the SUREGROUND™ Binder with soils, is there a dust risk?
Soil Science only use Dust Free mixers for the rotovation of SUREGROUND™ Binder, this mitigates any dust issue.
14. What is the depth of SUREGROUND™ treatment?
Soil Science will remove topsoil and condition subsoils to a depth of 350mm, traditional stone replacement designs with deeper design depths will disturb and affect a greater volume of soil.
15. What tests are conducted to check soil has returned to its original status?
Prior to the construction phase, samples are collected and tested to inform the design team of the natural pH and nutrient levels. The efficacy of the reversion technology is also tested through laboratory trials prior to works commencing to demonstrate that natural pH and nutrient levels can be attained following restoration.
Upon completion of restoration works, validation samples are collected and analysed to verify restoration works have returned the soils back to their original pH and nutrient status as described by DEFRA indices.
16. Who undertakes the testing?
Testing is conducted by an independent third-party specialist environmental geochemistry laboratory with analytical results produced under ISO 17025 UKAS accredited methods.
17. What is the time period required for the soil pH and Nutrient to return to its original values once the process is complete?
Reversion of pH following addition of regenerative reagents is almost immediate with stable pH and nutrient conditions re-established within several days following restoration.
What is SUREGROUND™?
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