Determining Abrasion Rate of Armourstones Using Physical Modeling Techniques

Abstract

Estimating the service life of armourstones used in rubble mound breakwaters remains a controversial issue in coastal engineering. Classification systems investigating durability of armourstones in the literature deal with “potential” performances using engineering properties of intact rocks which are determined in dry conditions. However, “actual” performance loss in armourstones is due to the abrasion in a wet environment, which is a function of time and sea wave impact on the rocks. In this study, actual abrasion rates of basaltic armourstones taken from Giresun Port (Eastern Black Sea, Turkey) are determined by using the Slake Durability test apparatus, which is the only suggested ISRM method for measuring abrasion of rocks in wet condition. However, the standard test method was modified so that microscale models of basaltic rocks from different weight classes were exposed to a number of wave attacks with sea water taken from the port. Therefore, actual abrasion rates of armourstones were determined in an ISRM accepted apparatus but with a new and realistic approach.