Calcinor - Geotechnical improvements from using lime

Tests prior to dosing

Before going onto the stabilisation operation on site, a series of tests should be carried out to determine the most suitable lime dose to achieve the optimum geotechnical results in the land. These tests basically consist of establishing what improvements will be obtained in the geotechnical parameters with different doses (generally between 2% and 4% of lime): tests for plasticity index, swelling, compacting and load-carrying capacity. Of particular importance is the pH test, which determines what level of dosage corresponds to a value of 12.4.

pH test in line with PN UNE 80-510

On site mixing: dry mixing system


1. Preparing the land: Plough the land to encourage the soil-lime mix. Not always necessary.	2. Spreading the lime: Distribution should be made using a volumetric dosing unit controlled by the speed of the spreader as it moves forward.	3. Slaking the lime: When using quicklime it will be necessary to slake the lime in place by watering the spread lime.


4. Mixing: This operation should achieve a uniform mix of soil and lime. It is advisable to use a high mixing energy pulveriser/mixer.	5. Compacting: The mixture is compacted by means of pneumatic compactors in successive layers. Stringent control is needed of the optimum humidity level of compaction of the soil/lime layer.	6. Refining: Finally, the upper layers can be refined. This operation is flexible in terms of lime use, and can be carried out some days after the mixing and compacting operation.

Mixing on site: wet mixing system

The operational process is similar to the dry mixing system, except that a unit is used to mix the lime with water to produce the milk of lime which is then injected directly by means of the pulveriser.

Lime/water mixing unit