Correlations Between Slake-Durability Index and Engineering Properties of Some Travertine Samples Under Wetting–Drying Cycles

Six travertine rock samples have been collected from different parts of Cheshmeh-Hafez quarry in northwest of Damghan, northern Iran. Physical and mechanical properties of the samples mean dry and saturated unit weights, specific gravity, porosity, water absorption, ultrasonic P wave velocity, Schmidt rebound hardness, point load index, Brazilian tensile strength, block punch index and uniaxial compressive strength have been determined according to the ISRM (in: Ulusay, Hudson (eds) Suggested methods prepared by the commission on testing methods, International Society for Rock Mechanics (ISRM), Kozan Offset, Ankara, 2007 ) standard in the laboratory. Also, slake-durability test was carried out up to ten cycles in different solutions. The used solutions were natural water with pH 7 of the region and sulfuric acidic solutions with pH of 5.5 and 4. Then empirical relationships by regression analyses were undertaken between the slake-durability indexes of all cycles of the test and measured physical and mechanical properties of the tested travertines. Regression analyses indicated that the relationships with correlation coefficients (R 2 ) from 0.55 to 0.98 exist between slake-durability index and engineering properties of the rocks. The best and poor correlations were obtained between slake-durability index and specific gravity and block punch index, respectively. Results shown that in the first four wetting–drying cycles, the correlation coefficients between slake-durability index and physical properties of the rocks are rapidly increased, whiles the increasing rate of the correlation coefficients between slake-durability index and mechanical properties of the rocks is maximum in the first three cycles. Therefore, the first and second cycles of slake-durability test can’t able to present actual durability of the rocks.