pricklyPete
Structural
I am currently working on a project where the contractor wants to use clay bricks to support the bottom mat of reinforcing (They are actually shale bricks with test breaks well above 10,000 psi).
I was told early in my career that clay bricks should not be used to support rebar because they will expand if they become wet and crack the concrete. I can understand the concern when the clay bricks are in direct contact with the soil.
However, in this case, the bricks do not sit on the soil. They sit on a lean concrete mud mat that is roughly 2" to 3" in thickness, which should help to protect the bricks from moisture. This foundation is very large and the support bricks are spaced far enough away from the edges such that blowing out the sides of the concrete due to expansion is not a likely possibility.
I am aware that ACI says that reinforcement supports should be of either concrete, steel, or plastic material. What I am wondering is if anyone sees any issues with using clay (or shale) bricks in this particuluar scenario?
I was told early in my career that clay bricks should not be used to support rebar because they will expand if they become wet and crack the concrete. I can understand the concern when the clay bricks are in direct contact with the soil.
However, in this case, the bricks do not sit on the soil. They sit on a lean concrete mud mat that is roughly 2" to 3" in thickness, which should help to protect the bricks from moisture. This foundation is very large and the support bricks are spaced far enough away from the edges such that blowing out the sides of the concrete due to expansion is not a likely possibility.
I am aware that ACI says that reinforcement supports should be of either concrete, steel, or plastic material. What I am wondering is if anyone sees any issues with using clay (or shale) bricks in this particuluar scenario?
