Autogenous Strain of Cement Paste and Mortar

The Auto-Shrink system measures the unrestrained autogenous shrinkage of a specimen of cement paste or mortar cured under sealed conditions as per standard ASTM C1698.

When cement hydrates through chemical reactions with water, the volume occupied by the products of hydration is less than the original volume of cement and water. This phenomenon is known as “chemical shrinkage.”

Auto-Shrink is intended primarily for measurements after setting of cement pastes or mortars with a maximum aggregate size of 2 mm. To minimize the influence of temperature variations, the dilatometer should be used in a thermostatically controlled room. Background information on the measurement technique used in Auto-Shrink.

Let see the testing procedure:

For more details about the instrument: http://germann.org/products-by-application/autogenous-shrinkage/autogenous-shrinkage

For dry shrinkage testing as per ASTM C1567 / ASTM C1698, watch the below video:

Many thanks for google.com and Germann Instruments from where the details are collected.