Our stabilisation service

Quality Management

1. Confirm soil properties before treatment are the same as assumed in the design. If changes are found then refer back to the designer.
2. Assess moisture content of material before treatment to adjust binder or water content if required
3. Check rate of spread of binder and adjust rate of spread if required; or re-spread if insufficient binder has been added
4. Check mixing depth by hand dug trial holes and adjust and re-mix to the correct depth if necessary
5. Assess moisture content of mix after mixing – the mix should bind together and be homogeneous when moulded into a ball by hand. For cohesive soils particularly those to be treated with lime only, targeting a moisture content wet of optimum is recommended. NDG gauge readings will provide a guide to moisture content. Take samples for laboratory moisture content testing to correlate with gauge readings. Where practical, consider rapid methods for moisture content testing, such as microwave oven for granular materials or MCV for cohesive materials and adjust water addition accordingly
6. Check the pulverisation after mixing. This is important for cohesive materials, especially heavy clays, to ensure that the binder is well mixed. Multiple passes or an extended mellowing period can be required for some materials to break down. This should be determined from initial trials and replicated in the main works. Remix if satisfactory pulverisation is not achieved
7. Check the performance or strength of the mix at agreed intervals and take samples for relevant laboratory testing
8. Check the compaction by in-situ testing and compare with refusal densities from laboratory specimens or a target density from compaction curves. Define compaction method from site trials and replicate for the main works. Close control and feedback to the roller operator is essential while the material is still workable, so that additional passes can be made if required
9. Check levels while material is still workable. If too low, more material will be placed, then the full depth of the stabilised layer re-mixed, adding more binder if deemed necessary
10. Complete any performance testing on the finished layer if required. Allow curing time required for the material to gain strength before testing and trafficking in accordance with specification
11. Protect finished works from damage by signage or physical barriers where required, until it has reached the required strength or performance for the intended use
12. For cold weather working, ensure that materials are frost free before treatment and treated materials are protected when low temperatures are anticipated. Additional curing time before trafficking may be required due to slower strength gain at lower temperatures
13. For hot weather working consider treating smaller areas so that works are completed before the material dries out
14. Site trials are important to establish working methods that should be used for permanent works and achieving any specific performance criteria

Testing, testing...

With our own in house lightweight deflectometer, we can test our completed work as we go.  Our LWD gives an instant stiffness reading on the compacted stabilised layer, in an Mpa format recognised and required by Local Authorities and overseeing consulting engineers.  This pro-active approach to testing builds confidence with the client on the performance of the stabilised platform, be it an adoptable road, piling mat, compound, or crane mat.