Abstract
This paper investigates the in-plane response of ambient-dry and wet clay-brick/lime-mortar masonry walls under lateral cyclic loading and co-existing compressive gravity load, as well as of square masonry panels under diagonal compression. The properties of the constituent materials were selected to resemble those of existing heritage masonry structures in Historic Cairo. After describing the specimen details and testing arrangements, the main results and observations are provided and discussed. The full load-deformation behaviour of the large-scale wall members is also evaluated , including their ductility and failure modes, and compared with the predictions of available assessment models. It is shown that moisture has a detrimental effect on the main material properties, including the diagonal tension and compression strengths as well as brick-mortar interaction parameters. For the large-scale wall specimens, the wet-to-dry reduction was found to between 8-11% for the lateral strength and around 10% in terms of ductility. The response of diagonal walls was relatively brittle with a reduction between wet-to-dry strengths of around 33%, suggesting that the reduction ratio is dependent on the compression stress level. Provided that the key moisture-dependent masonry properties are appropriately evaluated, it is also shown that analytical assessment methods can be reliably adapted for predicting the response.