ACI 350 Shrinkage and Temperature Reinforcement Movement Joints

[Recent Grad Josh]

Hello,

I am designing the horizontal reinforcement in a 18'x10' rectangular tank. There are no movement joints, and I'm wondering if I need to satisfy the full 0.005 reinforcement ratio which is required between movement joints spaced at 40' or greater (Grade 60 rebar). Or do the tank corners act as "movement joints" and thus only need the 0.003 ratio (which is the case for spans less than 20' between movement joints)? Ref ACI 350-06 Table 7.12.2.1

 

[JAE]

My vote would be .003 rounded up a bit.
The movement of the wall along its length will try to bend the orthogonal walls inward or outward - some resistance but certainly not the same as a longer continuous wall.

Check out Eng-Tips Forum's Policies here:
faq731-376

 

[hokie66]

As it is a tank, it should be designed as a water retaining structure, assuming water is the contents. Not really familiar with ACI350, but 0.05 or 0.06 is appropriate for water retaining structures.