Page 139 - RoadCem Manual - PCT BV

5. Calculate the wet weight of soil sample, SWw, needed for the preparation of the sample using the formula below:
6. Calculate the amount of water needed to prepare the sample, Ww, kg, using the formula below: ,
Once all the above values have been determined the procedure to prepare the samples is as follows:
Step 1. Measure SWw, kg of soil and place in a mixer and homogenize making sure that there are no lumps of any significant size forming
Step 2. Add 100 gr of RoadCem and Mix well to ensure uniform distribution
Step 3. Add the required amount of Cement as per Cement design dose (for Queretaro the design dose is 120 kg/m3 of soil) – To calculate the amount of Cement needed multiply the design dose by a fraction represented by sample size, i.e. and mix to ensure uniform distribution.
Step 4. Add the required amount of water+2% and mix thoroughly
Step 5. Prepare cylinders and/or cubes and beams for testing by placing the material in appropriate moulds and compacting to MPD, maximum Proctor Density. Cover with moist cloth.
Step 6. De-mould after 24 hours and cure in air under wet cloth until testing date.
It is often necessary to prepare more than one mix with different doses of RoadCem and Cement in order to find the optimum dosage rate for a prticular application. In such cases for each dose the minimum sample size has to be determined. The samples prepared are than tested at 7, 14, 28 days etc.
More detailed analysis will involve field sample collection and determination of the load bearing characteristics of the soil under field conditions. As a minimum the laboratory tests should involve the determination of:
• Modulus of Elasticity.
• Compressive Strength.
• Flexural Strength.
• Breaking Strain.
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