Combining expansion/shrinkage monitoring and X-ray measurement for water and salt transport in calcium silicate beam

Salt transport in building materials may lead to damage due to expansion forces of crystals formed during drying processes. In order to estimate the effect of these forces calcium silicate is examined. The drying of specimens initially saturated with a water and a salt solution of 1.0 M Na₂SO₄ is studied. The water content is measured by X-ray projection at regular time steps. Simultaneously, shrinkage due to drying and expansion due to growing of crystals are monitored by a test set-up with displacement transducers (lvdt). To force salt crystals to form inside the material, tests are executed with hydrophobated samples.