Title: Studies on Marine Epilithic Organisms to No Fines Concrete Using Slag Cement and Portland Cement With Silica Fume

Author(s): M. Tamai and Y. Nishiwaki

Publication: Symposium Paper

Volume: 132

Issue:

Appears on pages(s): 1621-1636

Keywords: epilithic organisms; marine atmospheres; no-fines concretes; seawater; silica fume; slag cements; slags; Materials Research

DOI: 10.14359/2244

Date: 5/1/1992

Abstract:
Purpose of this study was to search for ecologically acceptable ways to stimulate the natural self-purification activities in water areas. For this purpose, attachment of marine organisms to the surface of no-fines concrete (NFC), which contains continuous voids that may be effective in promoting establishment of a biologically favorable environment, was examined. When this type of concrete is immersed in shallow seawater, not only its rough surface, but also its continuous interior voids, are fully exposed to water and rapidly neutralized. This will then lead to the attachment and growth of marine microbes and eventually to the formation of a layer of biotic membranes. Attachment of organisms seems to occur in a form of multilayered biotic membrane consisting of bacteria, various microbes, unicellular algae, small animals, large seal algae, and shellfish, etc. Results show that decomposition and ineralization of the marine organic matters and the growth of algae, attached animals, and bacteria are accelerated, thereby providing the water area with a better biological environment. Thus, this type of concrete may be useful in the establishment of a well-balanced biological environment and, although there is a limitation due to its thickness, in the construction of gathering places for fish. In addition, assimilation and fixation of carbon dioxide by attached algae and shellfish, respectively, may be also possible.