Durability of Lightweight Aggregate Concrete in Marine Structures

摘要

Lightweight aggregate concrete (LWAC) has been applied in marine structures in recent years due to its lower density compared to conventional concrete. The main durability issue is the corrosion of steel reinforcement induced by the chloride ion ingress and subsequent spalling due to volume expansion of steel rust. Besides, a damaged surface is prone to water absorption and loss of effective buoyancy in the case of floating structures. This paper presents two chloride resistance tests and a long-term water absorption test on LWACs cast using two types of coarse lightweight aggregates and various percentage of silica fume. The test results show that, with the same water to cement ratio and silica fume percentage, LWAC cast using expanded slate has a better chloride resistance than those using expanded shale. Besides, increasing the percentage of silica fume could yield a better durability performance of LWAC.