Abstract
To avoid the steel corrosion problem in coastal and marine environments, the use of fibre-reinforced polymer (FRP) composites in construction is gaining increasing acceptance. The application of durable FRP reinforcement in concrete structures opens a new avenue for concrete production with the direct use of seawater and sea-sand which are locally available for coastal and marine infrastructure. The resulting structures, referred to as FRP-reinforced seawater sea-sand concrete (FRP-SSC) structures, offer compelling environmental and economic advantages through reduced river-sand mining as well as savings in freshwater and material transportation cost. FRP-SSC structures were first proposed by Professor Jin-Guang Teng in 2011 at a national conference in China and have since kindled growing research interests. The series of International Workshop on Seawater Sea-Sand Concrete (SSC) Structures Reinforced with FRP Composites (FRP-SSC Workshop) was initiated in 2016 by Professor Teng against this background and has developed into an annual event. The Third FRP-SSC Workshop, jointly organised by The Hong Kong Polytechnic University (PolyU) and the Southern University of Science and Technology (SUSTech), was held on 11–12 January 2020 in Shenzhen, China and attracted nearly 200 participants; Professor Jin-Guang Teng (PolyU) chaired the organising committee, with Professor Jian-Fei Chen (SUSTech) and Professor Tao Yu (PolyU) as the co-chairs.
This special issue contains 14 invited papers contributed by the speakers of the Third FRP-SSC Workshop and some other renowned researchers in this area. These papers cover various aspects of FRP-SSC structures and closely related topics including (1) fundamental mechanisms and properties of SSC and concrete made with seawater or sea-sand (hereafter collectively referred to as SSC); (2) mechanical behaviour of FRP-SSC structural members; (3) durability of FRP, SSC and FRP-SSC structural members; and (4) sensing technology for these structures. There are four papers on the SSC material which cover the mechanism of strength evolution of seawater cement paste as well as the effects of key factors, such as the salinity of mixing water, the fibre content, and the strain rate, on the properties of SSC. Another set of four papers is on FRP-SSC structural members including compression and flexural members, covering various aspects of structural behaviour including the behaviour of FRP-SSC interfaces and FRP-confined SSC as well as the punching shear behaviour of slabs and seismic behaviour of columns. The third set of four papers is on the durability of FRP, SSC and FRP-SSC structural members, covering both experimental studies and molecular dynamics simulation. In addition, there is one paper on the development of novel sensors for potential applications in FRP-SSC structures and one review paper focusing on the use of coral aggregate in concrete structures.
The editors of this Special Issue would like to thank the authors for their fine contributions and thank the reviewers for their timely and high-quality reviews. We are also grateful to Professor Jin-Guang Teng and Professor Yong Xia, the two Co-Editors-in-Chief at the time the proposal of the Special Issue was accepted, for their strong support.