Durability assessment of travertenes against salt weathering: an experimental study

Considering the diverse climatic conditions of Iran with a varying from hot and dry and also coastal areas it can be seen that salt weathering is one of the most important agents affecting on the durability of stones used as wall cladding of the building. As a result it is necessary that durability of stones be assessed and the most resistance and appropriate those be selected for use as wall cladding of the buildings. In this research, durability of six samples of travertines from Azarshahr and Mahallat areas against salt weathering were investigated. For this purpose, salt weathering test at sulfate sodium (Na2SO4) up to 60 cycles was carried out and, after every 5 cycles, changes in the samples appearance (color, efflorescence, chemical and physical decay), mechanical properties (point load strength, Brazilian tensile strength and P-wave velocity) and Dry Weight Loss of samples were monitoring and measured. The results indicated that changes in samples appearance including the color, efflorescence, chemical and physical decay due to criteria of measure those is qualitative, can not to be appropriate for assessment of samples durability against salt weathering. Moreover, results show in among parameters that criteria of measure those is quantitative, Brazilian tensile strength and P-wave velocity are more reliable in compare with point load strength and Dry Weight Loss for assessment of samples durability. Also, macroscopic monitoring of samples appearance against salt weathering show that petrological properties have major role in chemical and physical decay and therefore their durability.