Water Sorption Isotherms of Some Building Materials

Abstract:

Moisture is one of the most deteriorating factors of buildings. The masonry moisture content depends on hygroscopic equilibrium between building materials and environment. Moisture sorption (adsorption and desorption) isotherms of 4 sandstones, 2 bricks, and 6 plasters were determined at 15, 25, and 35°C. A modified Oswin equation was used to predict experimental data for water activity in the range between 0.03 and 0.90. The hysteresis phenomenon between adsorption and desorption was observed for all the examined materials and classified at various isotherm types. A correlation of the hysteresis type with the microstructural characteristics of the materials was attempted.

Keywords:

• Bricks
• Oswin equation
• Plasters
• Stones

Notes

b ₁ = 3.00E + 03 (K).

b ₂ = 3.60E − 01 (−).