Experimental investigation of water absorption and penetration in clay brick masonry under simulated uniform water spray exposure

In this study, we performed an experimental investigation of water absorption and penetration in clay brick masonry exposed to cyclic water spraying by employing a newly developed test setup. Several parameters, including brick absorption properties and different mortar joint profiles, were investigated. The specimens were exposed to a uniform water spray rate ranging between 1.7 and 3.8 l/m2/h, and water absorption and dampness patches on the non-exposed backside (the protected side) of the specimens monitored continuously. The results indicate that the amount of absorbed water is highly dependent on the water absorption coefficient and absorption capacity of the bricks, whereas the mortar joint profiles do not influence water absorption. The first dampness patches on the specimens' backside appeared in the vicinity of the head joint, and the time until the first patch appeared correlated well with water content levels. Accordingly, the first visible dampness patches appeared on the specimens' backside at water content levels corresponding to 50%–60% of full saturation level. Additionally, the specimens' backside reached 90% dampness at water content levels corresponding to 95% of full saturation level. As a feature attributed to the absence of known defects and zero differential air pressure, no measurable amounts of penetrated water could be collected at the specimens’ backside. The newly developed test setup might facilitate verification of moisture simulations and provide a basis for rational decision-making concerning clay brick masonry design and maintenance.