Three renders commonly used in the Czech Republic on the exterior side of building envelopes are exposed for 2 years to the environmental conditions of the city of Prague. The effect of external environment on their possible damage is monitored using the measurement of a variety of material properties in selected time intervals. The experimental results do not show any significant deterioration of most parameters during the 2-year investigation period. The open porosity is found to decrease with time due to the continuing hardening processes. The mechanical properties are thus improved after 1 year of exposition and only little worsened after the second year. The changes in the pore structure also result in deceleration of water- and water-vapor transport and a slight increase of thermal conductivity. The obtained results will serve as reference data for finding a correlation between the accelerated laboratory tests and the behavior of analyzed materials in real building structures.
basic physical properties, environmental effects, exterior plasters, liquid water transport, strength, thermal properties, water vapor transport
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