Investigation on the yield and failure criterion of foamed concrete

This study systematically investigated the yielding and failure criterions of foamed concrete through the proposed control equations. Firstly, four loading-path experiments including uniaxial tension, uniaxial compression, triaxial shear, and isotropic compression were conducted to comprehensively analyze the mechanical behaviour of foamed concretes. The results indicated that foamed concretes experienced elastic stage, softening or hardening stage, and strength stability stage subjected to the uniaxial loading. During the loading process, some cemented binders within foamed concretes would be broken into particles and then moved to fill the internal pores. Afterwards, the failure criterion of foamed concretes was explicated based on the critical state theory, where two control equations regarding stress and deformation aspects were proposed. Finally, a yield function containing tension, compression, and shear loading paths was proposed to describe the yielding performance of foamed concretes. Compared with the experiment data, the prediction accuracy of the proposed yield function has reached more than 95 %. This research provides theorical basis for the practical application of foamed concretes.