Moisture storage capacity and microstructure of ceramic brick and autoclaved aerated concrete

The moisture storage capacity of two different types of building materials – autoclaved aerated concrete (AAC) and burnt clay brick was determined from the water vapour sorption isotherms. The pore structure parameters were determined by means of nitrogen adsorption/desorption tests and mercury intrusion porosimetry (MIP). It has been found that the compatibility of the pore structure results achieved by nitrogen sorption and MIP was good in case of bricks but was weak in case of AAC materials. The comparison of water and nitrogen sorption results showed that for all tested materials, the adsorption storage capacity determined from nitrogen sorption agreed satisfactorily with the moisture storage capacity stated from water vapour sorption for the range of relative pressures higher than 0.3. Based on the results, the method of evaluation or verification of water vapour adsorption curve using the nitrogen sorption results was suggested.