Experimental studies on mechanical properties of steel reinforcements under cryogenic temperatures

Abstract

The increasing demands of the liquid natural gas (LNG) container and engineering constructions in the cold regions require the reinforcing steels could work under the cryogenic temperatures. This paper reported the experimental studies on the mechanical properties of HRB335, HRB400, and SLTS type of reinforcing steels that were used in the reinforced concrete structures and LNG containers. A test program consisted of 63 steel coupons was performed under different cryogenic temperatures ranging from −165°C to 20°C. The test results revealed the influences of the cryogenic temperatures on the mechanical properties of the different reinforcing steels that included stress-strain behaviours, elastic Young’s modulus, yield and ultimate strength, fracture strain, and percentage of reduction in the cross sectional area. Discussions were also made on the differences of the influences of the cryogenic temperatures on the mechanical properties among different types of reinforcing steels. Based on the test results, empirical design equations were developed through the regression analysis on the reported test results. The accuracies of these developed equations were checked through validations of the predictions against the test results. Conclusions and design recommendations were made based on these experimental and analytical studies.