oengineer
Structural
- Apr 25, 2011
- 732
What does ACI 350-06 consider to be the shrinkage and temperature reinforcement for both top & bottom reinforcement for Slabs/Mat Foundations?
If I have a vertical pump foundation for a water plant facility, what would be the appropriate way to provided min reinforcement in both the top & bottom layers (see image) using 0.003? The reinf steel is grade 60.
Section 7.12.2.1 states the following:
"For members subjected to Environmental Exposure Conditions or required to be liquid tight, the area of shrinkage and temperature reinforcement shall provide at least the ratios of reinforcement area to gross concrete area shown in Table 7.12.2.1:
Concrete sections that are at least 24 in. may have the minimum shrinkage and temperature reinforcement based on a 12 in. concrete layer at each face. The reinforcement in the bottom of base slabs in contact with soil may be reduced to 50 percent of that required in Table 7.12.2.1."
Since the slab in question is supported by soil, I would think the 50% reduction could be applied to the bottom layer. But would the top layer need to satisfy 0.003 alone? I am going to use #5@6"o.c for both top & bottom layers.
I know for ACI 318, the min reinf can be split between both top & bottom reinf layers to be considered satisfying the S&T reinf from the code. Is this applicable to ACI 350 as well?
Suggestions/comments are appreciated.
If I have a vertical pump foundation for a water plant facility, what would be the appropriate way to provided min reinforcement in both the top & bottom layers (see image) using 0.003? The reinf steel is grade 60.

Section 7.12.2.1 states the following:
"For members subjected to Environmental Exposure Conditions or required to be liquid tight, the area of shrinkage and temperature reinforcement shall provide at least the ratios of reinforcement area to gross concrete area shown in Table 7.12.2.1:
Concrete sections that are at least 24 in. may have the minimum shrinkage and temperature reinforcement based on a 12 in. concrete layer at each face. The reinforcement in the bottom of base slabs in contact with soil may be reduced to 50 percent of that required in Table 7.12.2.1."

Since the slab in question is supported by soil, I would think the 50% reduction could be applied to the bottom layer. But would the top layer need to satisfy 0.003 alone? I am going to use #5@6"o.c for both top & bottom layers.
I know for ACI 318, the min reinf can be split between both top & bottom reinf layers to be considered satisfying the S&T reinf from the code. Is this applicable to ACI 350 as well?
Suggestions/comments are appreciated.