A study on the seawater purification characteristics of water-permeable concrete using recycled aggregate

This study investigated and analyzed the physical and mechanical properties as well as the seawater purification characteristics of water-permeable concrete using recycled aggregate, granular artificial zeolite, silica fume and glass fiber in order to present effective utilization of waste concrete aggregate and derive a method to improve the performance and seawater purification characteristics of water-permeable concrete. The strength test result showed that the strength increased as the mixing ratio of the recycled aggregate was increased. However, it demonstrated the characteristics of greater compressive strength and flexural strength than plain concrete by 50 and 75%, respectively. The result of measurement for the dissolved oxygen consumption amount as well as T-N (total nitrogen) and T-P (total phosphorous) after the water-permeable concrete was immersed in the artificial water channel indicated that as the target void ratio was greater, the seawater purification performance was more excellent. In addition, it was found that the mixing of the granular artificial zeolite is effective for seawater purification. Therefore, it was discovered that even though the aggregate was replaced with recycled aggregate when making water-permeable concrete for seawater purification, if an appropriate amount of admixture was mixed, the recycled aggregate was effective for the physical and mechanical properties as well as the seawater purification characteristics. It was thought that the appropriate mixing ratio of the recycled aggregate was approximately 50% when the target void ratio was set to 20%.