Stone Masonry – Effect of Bed Orientation Relative to Load When stones in masonry are placed so that their natural bedding layers are parallel to the direction of the applied compressive load, what is the likely behavior in service?

Introduction:
Natural stones are anisotropic due to bedding or foliation planes formed during geological processes. The orientation of these planes relative to structural loads significantly affects performance in masonry. This question examines the risks when layers run parallel to the applied load direction.

Given Data / Assumptions:

• Many stones have distinct bedding/lamination planes.
• Load is applied vertically (e.g., in a wall or column stone).
• Moisture may penetrate along planes of weakness.

Concept / Approach:

When bedding planes are parallel to the load, shear and splitting can occur along those planes, reducing effective compressive capacity. Moisture ingress along layers fosters deterioration (freeze–thaw, salt crystallization), further weakening the stone. Standard practice is to place stones so that bedding planes are normal to the principal compressive load where possible.

Step-by-Step Solution:

Verification / Alternative check:

Stone masonry guides recommend orienting beds normal to load to exploit compressive strength across layers and reduce delamination risks.

Why Other Options Are Wrong:

Choosing only one effect ignores the coupled mechanical and durability impacts; claiming increased strength contradicts practice.

Common Pitfalls:

Ignoring anisotropy; orienting for appearance instead of structural performance; underestimating moisture transport along bedding.

Final Answer:

Both (a) and (b)