Title:
Low Temperature Effects on the Microstructure of Cement Paste Exposed to Seawater
Author(s):
V. S. Ramachandran, M. S. Cheung Heung, and H. M., and H. M. Hachem
Publication:
Materials Journal
Volume:
87
Issue:
4
Appears on pages(s):
340-347
Keywords:
age-strength relation; cement pastes; compressive strength; low temperature; microstructure; porosity; portland cements; seawater; Materials Research
DOI:
10.14359/2051
Date:
7/1/1990
Abstract:
The microstructure and compressive strength of normal portland cement pastes made with a water-cement ratio of 0.25, precured at 4 C (30.2 F) for periods ranging from 3 to 15 hr, and then continuously cured in simulated seawater of different temperatures {-2, 0, 2 C (28.4, 32, 35.6 F)}, were examined at ages up to 180 days. At low precuring temperatures, the 1-day compressive strength increased with increasing precuring duration. After 28 or 180 days of curing in seawater, however, the compressive strength showed a reversed trend. The development of physical, chemical, and microstructural characteristics of the cement paste were consistent with the strength increases observed at age 1 day. At older ages, strength was no longer a simple function of the degree of hydration, as complex interactions occurred between the cement paste and salts. It was evident from the cement paste morphology that these interactions have results in a distinct paste composition that differs from that of specimens not cured in salt water.