What is the appropriate penetration depth for the tamping rod into the layer below while rodding?

The appropriate penetration depth for the tamping rod into the layer below while rodding is 1 inch. This measurement is based on standard procedures for compacting concrete in molds to ensure uniformity and consistency in the placement process.

When rodding, it is essential to penetrate the layer below sufficiently to bond the layers together and eliminate air voids, which can lead to weaknesses in the final concrete structure. A 1-inch penetration is a balanced approach that allows for adequate compaction without disturbing the bottom layer excessively. This method also aligns with common industry practices and guidelines, promoting the production of a dense and well-placed concrete mix.

When using a rod, if the penetration depth were greater than 1 inch, it might disturb the underlying layer too much, risking the integrity of the mix. Conversely, a shallower penetration would not effectively bond the layers, potentially resulting in delamination or air pockets that can compromise strength and durability. Thus, the 1-inch depth strikes the right balance for effective compaction and material performance.