How many voids do poured concrete, single brick, and hollow block filled with concrete foundation walls have?

Poured concrete, single brick, and hollow block filled with concrete foundation walls are considered to have zero voids because they are designed to create a solid mass that lacks empty spaces or cavities. In poured concrete, the material is typically solid once cured, providing a continuous and unbroken structure.

Single brick, when laid with mortar, forms a dense wall with minimal air gaps. Similarly, hollow concrete blocks filled with concrete are designed to be filled completely, thus eliminating the spaces that would otherwise be considered voids.

In the context of construction and structural integrity, the absence of voids is significant as it contributes to the strength, stability, and durability of the foundation walls. Therefore, selecting the answer indicating zero voids accurately reflects the characteristics of these materials in construction.