ACI Certification Practice Exam

When rodding the second and/or third layers, the rod must penetrate approximately how much into the previous layer?

1. 1/2 inch

2. 1 inch

3. 1.5 inches

4. 2 inches

The correct answer is: 1 inch

The correct choice indicates that when rodding the second and/or third layers of concrete, the rod should penetrate approximately 1 inch into the previous layer. This penetration is crucial for ensuring proper bonding between the layers, which contributes to the overall strength and durability of the poured concrete. Rodding involves using a rod to compact and consolidate the concrete, eliminating air pockets and ensuring that there is a uniform density throughout the poured layers. By penetrating about 1 inch into the underlying layer, the rod helps to create a strong mechanical bond, allowing the layers to adhere effectively to one another. This depth is generally acceptable in most standard practices for concrete placement and aligns with industry standards for achieving reliable structural integrity in concrete structures. Understanding the appropriate depth for rodding is vital because insufficient penetration could lead to weak points between layers, while excessive penetration might disrupt the underlying layer or compromise its structure. Overall, a 1-inch penetration is a balanced approach that promotes effective consolidation while maintaining the integrity of both layers.