Experimental study on scale effects in clay brick masonry prisms and wall panels investigating compression and shear related properties

•Experimental tests of full scale and half scale unreinforced masonry were presented.•Varying level of scaling influence depending on the failure mode of the masonry element.•Minimal influence due to scale on the brick strength, masonry strength, and Young’s Modulus.•The scaling have an effect on diagonal tensile strength and shear modulus. Scaled masonry model testing has been performed for many decades, with earlier researchers establishing that it is possible to model masonry behaviour at reduced scale, but that strength and stiffness are affected and with many studies suggesting that masonry is anisotropic. The effects of scale on clay brick masonry compressive strength, Young’s Modulus, shear modulus and diagonal tensile strength was investigated through material and component testing at two scales. Firstly, the effect of scaling the brick and mortar joints to half scale was assessed, and secondly, the effect of scaling the size of the specimen without scaling the brick and mortar size was assessed. Scale was found to have minimal to no effect in both test cases on the compressive strength characteristics of masonry and brick, and to have no effect on the stiffness of masonry in compression. The effects of scale were found to be significant for diagonal shear strength and shear modulus.