Structural behaviors evaluation of the frost damage for RC beams founded on non-coordinated deformation from pores

It is an important index for the frost resistance on durability evaluation of reinforced concrete (RC) structures in cold regions. In view of this, the meso-numerical simulation model of concrete under freeze-thaw cycles (FTCs) was established based on the non-coordinated deformation from pores under temperature, which considers the research on the pore structure of concrete. Subsequently, the calculation model for RC beams with FTCs was established to verify the calculation method and the theoretical calculation method was established for the calculation on the bending capacity of RC beams with FTCs. Moreover, the influence on frost damage of the structural behaviors was discussed and the effect of stirrups on the bending behavior of RC beams with FTCs was investigated by the meso-calculation model. The results show that the meso-calculation model can reflect the mechanical behavior of the frost damage for RC structures founded on non-coordinated deformation from pores. The non-linear behavior of specimens can be fully discussed by the meso-simulation model. The maximum deviation between the test and the meso-numerical simulation results is only 6.82%. The numerical calculation results of bending capacity are in coincidence with the test results. For the RC beams with stirrups, the expansion of pores and the development of micro-cracks are restrained by stirrups in confined concrete. Moreover, the existence of stirrups significantly inhibits the development of cracks, which improves the frost resistance of RC beams after FTCs.