Changes of pore structures in hardened cement paste subjected to flexural loading and wet-dry cycles in seawater

The coupling effect of flexural loading and environmental factors has great influence on the pore structures in hardened cement paste. In this paper, Mercury intrusion porosimetry (MIP) and field emission scanning electron microscope (SEM) were used to analyze and observe the changes of pore structures in hardened cement paste subjected to flexural loading and wet-dry cycles in simulated seawater. The results show that the porosity greatly increases when the flexural loading level is raised from 0 f (the ultimate flexural loading capacity) to 0.8 f Micro-cracks are observed and the connectivity, width and density of micro-cracks increase with the increment of flexural loading. The peaks position of pore size shifts toward greater micro-pores when the flexural loading was raised from Of to 0.8 f The flexural loading and simulated seawater accelerate the degradation of pore structures.