Adhesion between SRP and masonry: Laboratory simulations of the field moisture and salt conditions

Steel-reinforced polymer (SRP) composites are a new addition to the fiber-reinforced polymer (FRP) composite toolbox for structural strengthening. While several authors investigated the bond behavior of SRP composites applied to a masonry substrate, little is known about the role played by the presence of moisture and salt in the wall. This study aims at investigating the bond behavior of SRP-masonry joints under two conditions: i) SRP strips are applied to masonry blocks that have been previously subjected to an artificial weathering protocol consisting in salt crystallization cycles; ii) SRP strips are applied to masonry blocks, and then the SRP/masonry joints are saturated with water. Single-lap shear tests are conducted on the SRP-masonry joints that underwent those two conditions. Digital image correlation (DIC) is used to obtain the strain on the surface of the SRP strips. The distribution of salts in the masonry blocks and at the SRP-masonry interface after failure are investigated as well. Finally, the tensile strength of brick tested in both dry and saturated conditions is determined and compared.