Title:
Long Term and Accelerated Tests of the Resistance of Cements to Sea Water, with Special Reference to Aluminous Cements
Author(s):
C. M. George
Publication:
Symposium Paper
Volume:
65
Issue:
Appears on pages(s):
327-350
Keywords:
accelerated tests; corrosion; corrosion resistance; exposure; high alumina cements; porosity; portland cements; prisms; sea water; tests; water-cement ratio.
DOI:
10.14359/6361
Date:
8/1/1980
Abstract:
The excellent performance of aluminous cement concrete in sea-water is illustrated by a summary of long term exposure tests. Visual examination of laboratory semi-immersed 50 x 100 x 100 mm mortar prisms over 20 years confirms this result. Only rapidly converted (hot cured) specimens at total water/cement ratios >_0.6 show signs of attack after several years. To obtain more up to date information at low water/cement ratios, small (20 x 20 x 100 mm) mortar prisms have been tested for 5 years by semi-immersion in reconstituted sea-water and in tap water. Visual examination at chosen ages is followed by crushing tests on the submerged and exposed halves of each specimen. 16 low ( < 5 % ) C3A portland cements and 7 different aluminous cements have been studied, at constant mortar consistency. Visual examination of small prisms does not provide conclusive comparisons. The crushing strength tests show that the aluminous cements outperform the portland cements, and also enable the relative performance of individual aluminous cements to be established. Complementary data shows that the porosity of converted aluninous cement is similar to and not greater than that of portland cement at the same water/cement ratio. Further work is in progress to distinguish between the role of intrinsic factors (chemical) and physical factors (porosity/permeability) in the relative resistance of portland cements and aluminous cements to sea-water and other corrosive agents.