Field Construction Process
Quantum Ground Stabilisation Pty Ltd for treating materials with Quantum Powder Formulation (QPF) and Quantum Liquid concentrate (QLC) additives.
General
The general process for stabilisation with the Quantum stabilising agents should follow Technical Specification, MRTS07B Insitu Stabilised Pavement using Cement or Cementitious Blends.
Key deviations from standard practice are as follows:
Assess field moisture content (undertaken by an experienced operative). Hand assessment to confirm whether the host material is around OMC.
Add the Quantum RTU liquid additive1.
1The Quantum RTU liquid additive is the dilute form of the Quantum Liquid concentrate (QLC), the active ingredient, which is diluted at the ratio of one part to four parts water.
Add the Quantum Liquid concentrate (QLC) additive to the water cart at the ratio of one part to four parts water.
Use the water cart to apply the Quantum RTU liquid additive at a rate of 0.25 litres per m2.
Run this through the host material to a depth of 250 mm.
After the Quantum RTU liquid additive has been added and blended with the host materials, the field moisture content needs to be assessed again by an experienced operative. Ideally, after the Quantum RTU liquid additive has been added we require the materials to be at or just over OMC. Depending on this assessment, determine if additional water needs to be added with a second water cart containing uncontaminated water. This should be done by noting2 that the Quantum Powder Formulation (QPF) will reduce material moisture by approximately 1% and that additional water will need to be added to take this into account. Therefore, a moisture content just above OMC will not be an issue at this point.
2It should be noted that the Quantum Powder Formulation (QPF) will reduce material moisture by approximately 1% and that additional water will need to be added to take this into account.
A second uncontaminated water cart is then used to dose the in-situ materials to achieve OMC. Run this through the host material to a depth of 250 mm. Recheck the moisture content of the materials by hand.
Once the desired moisture content (OMC or just above) has been achieved, apply Quantum Powder Formulation.
Apply Quantum Powder Formulation (QPF) with a spreader at the desired spread rate. This will be between 5 and 10 kg/m2 for a 250 mm stabilisation depth3, based on the results from the laboratory mix design process.
Run the Quantum Powder Formulation (QPF) through the host material to a depth of 250 mm.
Recheck the moisture content of the materials by hand. Once the desired moisture content (OMC or just above) has been achieved, commence compaction2,4.
3If the treatment is for a lightly trafficked or local government application, usually the Quantum Powder Formulation (QPF) is applied through the upper 100 - 150 mm of the subbase or upper 100 mm of a granular base to reduce costs. Application rates of QPF need to be adjusted based on stabilisation depth. E.g. between 2 and 4 kg/m2 per 100 mm depth of stabilisation.
4Here the rules applicable in conventional earth constructions hold true, i.e. the compaction should be performed with a moisture content at Proctor optimum or slightly above (or, e.g. in cases of imminent rain showers, immediately after construction). If for whatever reasons, the compaction cannot take place immediately so that the soil dries too much, the missing moisture has to be incorporated by means
Compaction to be carried out with appropriate compaction equipment to achieve a minimum of 100% of standard compaction.
As noted in the laboratory mix design process, the working time of the host materials stabilised with the Quantum stabilisation system must be assessed in accordance with Q136A Working time of stabilised material+, to determine the maximum length of time between mixing of materials with stabilisation additives and compaction. This determines the maximum time within which it must be blended and compacted.
Sample materials for laboratory assessment to check that mix design requirements have been achieved, to confirm moisture contents and to undertake compaction tests to calibrate densities.
Undertake nuclear density measurements on field compacted materials to check that densities have been achieved.
The Superintendent needs to sign off on the job to confirm that densities have been achieved before section can be handed over.
Layers are not normally used as a wearing course. For this purpose, it is strongly recommended to apply a thin surface coating, e.g. with a sprayed seal or asphalt, which
achieves a durable coating on the stable soil layer and keeps the road dust free. For appropriate Technical Specifications, see MRTS11, MRTS12 or MRTS30.
Surface is allowed to dry back for between 1-3 days before sealing commences. Seal as per standard practice, based on seal design process.
Note on weather conditions during construction
If it rains, stop the work. When it stops raining, wait until the material dries naturally and recommence work.
If rainfall is expected, the work can be interrupted at any time and continued at the same stage after an improvement of the weather occurs.
Otherwise, nothing else to be considered - provided the soil in question is workable.
Associated Technical Specifications
Technical Specification, MRTS07B Insitu Stabilised Pavement using Cement or Cementitious Blends
Technical Specification, MRTS11 Sprayed Bituminous Treatments (Excluding Emulsion)
Technical Specification, MRTS12 Sprayed Bituminous Emulsion Surfacing
Technical Specification, MRTS30 Asphalt Pavements
*Construction equipment
Motor Grader
e.g. Caterpillar Motor Grader 120 https://www.cat.com/en_AU/products/new/equipment/motor-graders.html
Researcher: Dr James Grenfell Australian Road Research Board
