Retaining wall joints
Retaining wall joints
(OP)
Hi all, would like to ask a pretty basic questions about the retaining wall joints. There are three joints used in concrete retaining wall construction 1. Construction joint 2. Expansion Joint 3. Contraction joint.
Now, I know that construction joint is formed when casting of a wall cannot be done in one go. The two other joints got me a bit confused , From what I understand reinforcing steel bars prevents shrinkage cracks, why then the need for the expansion and contraction joint?
Thanks in advance.
Now, I know that construction joint is formed when casting of a wall cannot be done in one go. The two other joints got me a bit confused , From what I understand reinforcing steel bars prevents shrinkage cracks, why then the need for the expansion and contraction joint?
Thanks in advance.






RE: Retaining wall joints
RE: Retaining wall joints
For a free standing wall, it is often appropriate to match an expansion joint in the building sitting on it. For a below grade wall cast against earth, it is probably more appropriate to consider the foundation wall as monolithic and provide for the buildings expansion as starting from the top of the wall. Some reasons - waterproofing expansion joints below grade is a bit more difficult. Contraction but not expansion (assuming a fully below grade wall) may occur due to long term settlement of surrounding soils causing the joint to slowly close over time and not match the superstructures behavior.
If you have a wall that will not be exposed to site and is well waterproofed on the exterior, I say let it crack and feel free to ignore the shrinkage cracks - let everyone know its going to happen though.
RE: Retaining wall joints
Expansion joints are a global consideration for large buildings that I don't think are related to your issue. It seems that you're asking about contraction joints. This link might be helpful:
Joints in Poured Walls
RE: Retaining wall joints