Testing Device for Soil Freeze / Thaw vessel according CBR-F Test (Standard: ASTM D5918 ).

These laboratory test methods evaluate the susceptibility of soil to frost heave and thaw weakening. This is done by assessing the heave rate and thawed bearing ratio in the lab and comparing these values against an established classification system.The frost swelling apparatus is especially designed for the ASTM Standard D5918. This standard describes the equipment, the procedure and the interpretation of the combined frost swelling test and the CBR test after the defrosting in the laboratory.

The test is carried out in a special manufactured, high-strength, insulating and deformation resistant CBR mould, made of synthetic fibre. It is used for the determination of the following parameters:

⦁ Maximum frost heaving

⦁ Residual heave

⦁ Frost heave coefficient

⦁ CBR value after the defrosting (CBRFH)

There are two cooling plates on top and the bottom of the specimen. The height changes of sample during freezing and thawing is measured by a high precision LVDT .

The test combines two test methods:

- The height change test

- The strength weakening