Experimental study on the capillary absorption of cement-based materials and analysis of influencing factors

Capillary absorption effect is very important to the research of concrete durability. Initial surface absorption test(ISAT)method has been employed to investigate the effect of W/C, age, aggregate volume percent and concentration of NaCl solution as a transmission medium of the capillary absorption of the cement-based materials. Experiment results indicate that, the capillary absorption coefficient increases with the increasing of W/C, but decreases with the increasing of age and aggregate volume percent. Within a certain range of low concentration, the capillary absorption coefficient increases with the increasing of the concentration of NaCl solution, however when the concentration is too high, the transmission rate will be lower than pure water. This investigation provides an experimental foundation for the durability design and service life assessment of concrete structures.