Numerical simulation for increasing the sand mastic adaptation of repairing the breakwater

Abstract

As a breakwater gradually becomes obsolete, it becomes vulnerable to loss of its original functions and finally occurs corruption due to cavitation, scours inside, etc. The mortar grouting method, which has been in general applied in many cases, would invoke serious issues such as coastal environmental pollutions because of spilled-out cement before curing on the near sea. Thus, the sand mastic that utilizes the mastic asphalt becomes focused on as a substitute. However, the related study is hard to find in the domestic literature. In this study, therefore, the workability of sand mastic when filling up the cavitation inside a breakwater was evaluated with a 3-D numerical model, FLOW-3D. It was intended to propose the workability index (WI) of sand mastic based on the diffusion diameter. It has been shown that the temperature and the composition ratio of the asphalt are the most significant parameters on the rheologic characteristics of the sand mastic. As a result, it is recommended that the asphalt composition above 16% and the initial temperature above 150℃ when applying with a breakwater with inside cavitation.