engleski

The Durability Characterization of Selected Marls from Dalmatian Region in Croatia

Flysch is one of the most frequently encountered rock mass in the engineering constructions in Dalmatian re-gion in Croatia. Marl as clay-bearing rock type form the major part of flysch formation. One of the main problems in construction in clay-bearing rocks is their susceptibility to degradation or weathering upon expo-sure. The sensitivity of a rock type against weatherability is usually described by a durability parameter, such as the slake durability index. In the majority of studies, the assessments for durability were based on the sec-ond cycle slake durability index. ISRM (1979) and ASTM (2004) suggested that two cycles can be used in the determination of the slake durability index. Although many rock types disintegrate at the end of the two cy-cles, they can have high slake durability index value. The variations in resistance of weak and clay-bearing rocks during short term weathering and deterioration indicate that durability is not detected satisfactory by second cycle slake durability tests. The type of slaking is strongly controlled by clay mineralogy and the con-centration of exchangeable sodium ions. But determination of mineralogy is time consuming and expensive. The primary purpose of this research was to establish no time consuming and inexpensive test that can be used as additional criterion for better classification of marl due to durability. Samples were subjected to four cycles of slake durability, point load tests, determination of dry density, determination of carbonate content and absorption of a water.

Weathering; Slake durability index; Marl; Strength degradation

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