Wave Reflection of Concrete Armour Unit: A 2D Physical Model Study

A breakwater is a coastal structure that breaks the wave energy coming towards the beach. When a wave hits an object, it will be reflected entirely or partially. Initially, the primary layer units on the coastal protection structure were only composed of large piles of natural stone. It is becoming increasingly difficult to find a natural stone of the right size, and to prevent its scarcity; natural stones are commonly replaced with concrete blocks. This study conducted the reflection coefficient analysis on the BPPT Lock concrete armor unit. Physical model testing was carried out on the wave channel of the Coastal and Port Infrastructure Laboratory, Department of Ocean Engineering ITS. From this study, it was found that the reflection coefficient on BPPT Lock ranges from 0.512 to 0.828 at a wave steepness of 0.002088 to 0.0117 with a structural slope angle of 1: 2. The reflection coefficient value is influenced by wave height, wave period, and the slope angle of the structure.