This study includes extensive compression tests on clay brick units, gypsum mortar, and masonry configurations, incorporating both gypsum and cement mortar, across four distinct scales 1:1, 1:2, 1:4, and 1:6. It investigates the relationship between compressive strength and modulus of elasticity, with the aim of providing precise estimation tools for these important mechanical properties. Systematic experimentation is employed, and scatter diagrams illustrate the dynamic interplay between modulus of elasticity and compressive strength. The derived coefficients, validated against experimental data, verify the accuracy of the proposed relationships. Specifically, the derived coefficient η, representing the ratio of modulus of elasticity to compressive strength, exhibits scale-dependent variations. For brick units, η ranges from 104 for the 1:1 scale to 126 for the 1:6 scale, emphasising the impact of size. Additionally, the coefficient η for gypsum mortar demonstrates a 20% increase with a rise in the water-to-gypsum ratio. Regarding masonry configurations, the coefficient η in the BS method varies from 91 for the 1:6 scale to 139 for the 1:2 scale. In the RILEM method, the coefficient η ranges from 48 for the 1:6 scale to 105 for the 1:1 scale. The proposed relationships display a negligible deviation from experimental results, affirming their robustness. Furthermore, a relationship is introduced for estimating masonry compressive strength based on the compressive strength of both the brick and the mortar at different scales. The accuracy of this relationship is verified by its minor deviation from experimental results. © 2024 Institution of Structural Engineers
