Final answer:
It is false that the compressive strength of mortar should be as high as economically feasible. Mortar must balance strength and ductility for overall wall resilience, especially under dynamic loads. Modern materials and reinforcement techniques are used to address the limitations of masonry under shear stress.
Step-by-step explanation:
For a masonry wall, it is false that the compressive strength of mortar should be as high as economically feasible. While the ultimate compressive strength of concrete is significantly high, making it unlikely for masonry blocks to break under compression, it is important to consider the ultimate shear strength as well. Concrete is strong under compression but quite poor against shear forces which can be critical in situations such as earthquakes or when heavily loaded floors are involved. In modern construction, materials such as steel and steel-reinforced concrete are used to overcome these limitations of concrete and brick masonry.
Moreover, a material's strength in a masonry wall is not only about withstanding compressive loads. The mortar's role is also to act as reinforcement, improving the ductility of the wall and increasing the strain range before reaching the breaking point. An extremely high compressive strength of mortar can lead to a stiff and brittle wall system that is more susceptible to failure under seismic or dynamically changing loads.
Thus, the ideal compressive strength for mortar should provide a balance between strength and flexibility, allowing for some movement and energy absorption, which contributes to the overall durability and resilience of the structure. Beth also highlighted the need for strong walls and piers to support heavy loads, emphasizing the importance of a comprehensive approach to material strength that accounts for both compressive and tensile stresses.