Effects of long-term exposure to elevated temperature on the mechanical properties of Hanford concrete

This report describes results of a 5-year testing program to determine the effects of long-term exposure to elevated temperatures on the mechanical properties of concrete used in constructing Hanford radioactive UGS tanks. Tests were conducted to determine concrete moduli of elasticity, Poisson's ratios, splitting tensile strengths, and compressive strengths of ambient conditions and after being subjected to elevated temperatures for periods of up to 2 3/4 years. Tests were also conducted to determine the influences of specimen geometry, steam curing, and cyclically varying temperature on these same properties. Related test programs were run to measure concrete thermal expansion, thermal conductivity, and creep behavior at elevated temperatures. In addition, a petrographic examination was made of selected specimens after heating and testing