EXPERIMENTAL STUDY ON COMPRESSIVE BEHAVIOR OF DIFFERENT STRENGTH GRADE CONCRETES EXPOSED TO -190℃

The compressive behavior of concrete exposed to -190℃ with different strength grades including C30, C40, C50, and C60 was investigated through experiments with 5 different kinds of mix proportion. The results showed the experimental macro-phenomena of concrete exposed to -190℃ differed greatly from those at normal temperature. The specimens tended to present an obvious brittle failure, and the failure modes of all specimens were alike. The compressive strength of all specimens exposed to -190℃ increased obviously, and the strength grade of concrete had a great influence on its compressive strength. The extent of the increase in concrete compressive strength depended greatly on the water content in the specimen. The compressive strength of concrete exposed to -190℃ with C30 and C40 was increased by 40% and 65%, respectively, and they became similar to those for C50 and C60 and increased to above 190% after their water content in concrete was increased. Based on the experiment results and the existing research results, a predictive model for the compressive strength of different strength grade concrete exposed to -190℃ was proposed and is expected to be applicable for reliable design and evaluation of concrete structures such as LNG tanks．