Title: Properties of Concrete at Very Low Temperatures

Author(s): Sho Yamane, Hideo Kasami, and Toru Okuno

Publication: Symposium Paper

Volume: 55

Issue:

Appears on pages(s): 207-222

Keywords: bending; bonding; compressive strength; concretes; cryo-genics; flexural strength; liquefied gases; low temperature; modulus of elasticity; moisture content; tensile strength; thermal expansion; thermal properties; thermal shock

DOI: 10.14359/6615

Date: 8/1/1978

Abstract:
Described in this paper are the test results of mechanical properties of several kinds of concrete mixes at very low temperatures and an investigation into the mechanism of change in their properties, for the purpose of obtaining design data for concrete structures exposed to very low temperatures, such as liquefied natural gas storage tanks and refrigerator warehouses. It was learned from the preliminary tests that the strength of concrete under the temperatures of the range of -1O'C to -7O'C was affected by moisture contents; the larger was the moisture content, the higher the rate of the strength increase was, and that the increase of concrete strength corresponded to that of ice at very low temperatures. Under lower temperatures of -1O'C to -196'C, it was verified that compressive strenth, modulus of elasticity and tensile and bond strengths of concrete increased with the decrease of temperature and the rate of increase in the strength and the elastic modulus was higher when the moisture content was larger. On the four mixes of concrete which had different water-to-cement ratios and air contents, tests were made, under the temperatures of down to -70°C, for compressive, tensile, flexural and bond strength and the modulus of elasticity. It was found that the rates of increase in these strengths were higher for the concrete with higher water-to-cement ratios and larger air contents. Also found by tests was the decrease in the strength; of concrete that received the very low temperature shocks between +20 and -196 C. The coefficients of thermal expansion of concrete were calculated from the measurements of the changes in the specimen lengths under the low and the very low temperatures, and were found to be smaller com-pared with those under room temperature. Further discussion is made on the influence of freezing of water in comparatively large pores under low temperatures and of the drop of freezing point of capillary water in smaller pores and accompanying freezing of water in these pores.