Influence of organic components and inorganic components of reed as a concrete admixture

Abstract

Vegetation in closed water area improves the natural environment by providing a habitat for juvenile shellfish and fish and by facilitating the intake of nutrients by plants. For these aquatic fauna, nutrient discharge occurs as mature individuals are harvested as fishery resources. However, aquatic plants are not typically harvested, so nutrients taken up by the plants as they grow return to the water in dead vegetation. These plants will not make a sustained contribution to the purification of the overall aquatic environment unless a system is developed to harvest them. In this research, we examine how reeds can be recycled. A potential application for the reeds is in mineral/chemical concrete admixtures. Reeds are rich in inorganic silica and organic lignin, both of which are effective as concrete admixtures. Silica is typically amorphous and is used as a pozzolanic admixture to impart long-term strength to concrete. Lignin is used as a water reducer admixture, which reduces concrete water content or slows the setting rate. The silica and lignin contained in the reed were examined from the viewpoint of strength development and flow of concrete. From the viewpoint of strength development, it was confirmed that long-term strength can be expected by replacing ashes of reeds with 5% of cement. Then, to improve mortar flow, reed powder was added to mortar as a water reducer at a weight fraction of 1% and was suitable in terms of phenol concentration. The results indicate that reed can be used as a chemical and physical concrete admixture.