Experimental and theoretical assessment of the long-term strength of lightweight concrete and its components under compression and tension, taking into account the macrostructure of the material

Experimental studies of concrete static fatigue require quite laborious and time-consuming tests. Insufficient data on static fatigue for concrete and the absence of an adequate theoretical base until recently did not allow using a generalized approach to estimate static fatigue parameters for different types of concrete. The paper presents the results of extensive experimental studies on static fatigue strength under tension and compression for lightweight concrete, mortar matrix, and hardened cement paste. A theoretical equation based on the fracture mechanics approach has been proposed and discussed for approximating experimental results and predicting static fatigue strength, which can be used for normalization of this parameter. The proposed equation displays better estimates compared to this used in the energy approach and empirical formulas