DEVELOPMENT OF POROUS CONCRETE MIXED WITH HYDROXYAPATITE PRODUCED FROM FISH BONES

Abstract

In recent years, environmentally friendly vegetated porous concrete (hereinafter, PC) has been required for revetment reinforcement in rivers, lakes, and other water bodies. Vegetation prefers a substrate with a high void ratio. However, an increase in the void ratio of the substrate leads to a reduction in its strength. On the other hand, in concrete used as a foundation for embankment slopes, ensuring sufficient strength is desirable. However, this often results in a lower void ratio. As mentioned above, in PC, it is generally difficult to achieve both a high void ratio and sufficient strength simultaneously. Fishbone-derived hydroxyapatite (hereinafter, FH) is a material recycled from fish residues. Its main component is calcium phosphate; calcium enhances the strength of concrete, while phosphate promotes plant growth ability. Therefore, this study focuses on FH with these characteristics and aims to develop PC with partial cement replacement by FH. In this study, physical property tests and plant growth experiments were conducted on PC to examine the effects of the presence or absence of FH on the strength and vegetation growth of PC. As a result, it was found that sufficient strength in PC was maintained even when FH was mixed into PC, and that the inclusion of FH contributed to the vegetation growth of PC. Additionally, low-carbon PC was achieved by replacing cement with FH.