Visualization of rapid penetration of water into cracked cement mortar using neutron radiography

•NR is an excellent NDT method to study water movement in building materials.•Rapid water penetration into crack was visualized with high temporal resolution.•Water front travelled through crack more than 20 mm within the first one second.•Time-dependent spatial moisture distributions in cracked mortar was quantified.

The penetration of water and other aqueous solutions into cracked cementitious materials is important in a variety of engineering contexts. The quick process of water penetration into cracked cement mortar during the first few seconds has been visualized for the first time with high temporal resolution of 10 fps by neutron radiography (NR). The results indicate that cracks are filled with water instantaneously by capillary action whenever they come in contact with water. The water front travelled more than 20 mm during the first second. Time-dependent moisture distributions in the cracked cement mortar during water penetration testing have also been quantitatively analysed.