Experiments aiming at characterizing the effects of moisture content and temperature on the mechanical properties of concrete were conducted. Based on the results of the experiments, theoretical formulations were proposed and a new overall material model capable of predicting the mechanical behaviour of concrete subject to elevated temperatures up to 100 C was developed. The new material model estimates the time, temperature and moisture dependency of the compressive strength, tensile strength, modulus of elasticity, creep and shrinkage of concrete. Consequently, this book provides specific knowledge about the influences of elevated temperatures and moisture content on the mechanical behaviour of concrete as well as a tool to calculate these influences. This shall contribute to the field of investigation of estimating the structural safety under ordinary and extraordinary loadings as well as to the area of evaluating the service life of concrete structures.