Nominal maximum size of coarse aggregate must be less than or equal to which of the following?

The nominal maximum size of coarse aggregate must indeed conform to multiple dimensional constraints during concrete construction to ensure adequate mixing, placement, and compaction.

Firstly, ensuring that the aggregate size is less than or equal to 1/5 the narrowest dimension between sides of forms helps facilitate proper concrete placement and movement around the reinforcements and within the forms. If the aggregate is too large, it may not fit easily through tight spaces, which could lead to voids or uneven distribution.

Secondly, the constraint of being less than or equal to 1/3 the depth of the slab is crucial for maintaining structural integrity. A larger maximum aggregate size can create challenges in achieving a homogeneous mix, and may affect the strength and durability of the concrete slab, particularly in ensuring that the aggregate can effectively interlock within the paste matrix.

Lastly, limiting the nominal maximum size of coarse aggregate to be less than or equal to 3/4 the minimum clear spacing between bars is significant for preventing potential blockages during placement. This ensures that the concrete can flow freely around reinforcement bars, effectively filling any gaps and achieving proper compaction, which contributes to the overall structural performance of the concrete element.

Thus, adhering to all these guidelines collectively ensures that the mixture behaves consistently