Use of FRP and Seawater Sea-Sand for Innovative Paving Slabs

Innovative paving slabs made of seawater sea-sand concrete (SSC) and fibre-reinforced polymer (FRP) bars have been recently used in the main road of a sewage treatment plant in Hong Kong. The use of durable FRP bars is to combat the deterioration of concrete structures due to the corrosion of steel, while it also allows the use of locally available seawater and sea-sand in concrete production, thereby addressing the shortage of fresh water and river sand for construction in coastal regions. This is part of an ongoing major project led by The Hong Kong Polytechnic University on the development of sustainable marine infrastructure enabled by FRP and SSC. Other features of the innovative paving slabs include embedded optical fibre sensors and smart aggregates for long-term monitoring of strains and temperatures, as well as specially designed grooves on the slab surface, which are realized with the assistance of precise 3D-printed formwork and serve the functions of guiding, harvesting and recycling rainwater together with an advanced drainage system embedded under the slabs.