Title: Permeability of Concrete in Sea Water

Author(s): Harvey H. Haynes

Publication: Symposium Paper

Volume: 65

Issue:

Appears on pages(s): 21-38

Keywords: cement pastes; concrete durability; high-strength concretes; hydration; marine atmospheres; mix proportioning; permeability; porosity; sea water; voids.

DOI: 10.14359/6344

Date: 8/1/1980

Abstract:
For fully hydrated concrete of excellent mix proportions, the minimum void volume is about 10%. The largest portion of the void volume is located in the cement paste which, viewed by itself as a solid matrix, has a minimum void volume of 28%. The size of the voids in the hydrated cement paste are sub-microscopic, but water molecules can move about and permeate the paste. Hence, the best concretes are permeable to water; however, the quantity of permeated water may be extremely small. Most of the published work on the permeability of concrete was based on using freshwater in the experiment. This paper summarizes some of the past work and presents results from a few studies on concrete exposed to seawater. One important new finding is that concrete permeated by seawater shows a decreasing permeability rate and it appears that permeability eventually stops. It is postulated that the reason for the decreasing permeability rate i s the blocking of pore space by crystallization or precipitation of chemical products created by the inter-action of seawater and hydrated cement.