The hight shear force is applied at the horizontal construction joints located at the lower level.
Spacing of expansion joints in concrete retaining walls.
Precast concrete cantilever wall expansion joints shall be in accordance with the standard specifications section 6 11 3 3.
Joints are commonly spaced at distances equal to 24 to 30 times the slab thickness.
These are vertical or horizontal joints that are used between two successive pours of concrete keys are used to increase the shear resistance at the joint.
The friction of the concrete is the key factor that limits the movement.
The engineered method is generally used only when unusual.
Recommended spacing of vertical contraction joints modified from ref.
Author spacing lewerenz 1907 75 ft 23 m for walls.
There is a special check to be done at the construction joints when larger retaining walls or structures having very high lateral loads are designed.
Cast concrete retaining walls may be constructed with any or all of the following joints.
Use projecting strips to reduce wall thickness by at least one fourth ref.
Consideration for the location of movement joints should be given at.
In reinforced walls and 6m in unreinforced walls.
Hunter 1953 80 ft 25 m for walls and insulated roofs 30 to 40 ft 9 to 12 m for.
Aci 224r 92 one to three times the height of the wall in solid walls.
For cantilevered and gravity walls vertical expansion joint spacing shall be a maximum of 60 feet on centers.
Expansion joints should normally be provided at a spacing of not more than 30m between successive expansion joints or between the end of the structure and the next expansion joint.
Table 1 2 expansion joint spacings.
In concrete walls the movement joints should normally be placed at a maximum spacing of 7 5m.
Joints in concrete walls.
Joint spacing in feet contraction joints may be tooled into the concrete surface at the time of placement.
2 wall height spacing 8 feet or less 3 times wall height.
Joints in poured walls by kim basham and bruce suprenant effective methods for controlling unsightly wall cracking f i g u r e 1.
Change in wall height or thickness see figure 1 figure 2 change of loading see figure 3 abutments of walls and columns see figure 4 junctions of dissimiliar materials see figure 5 movement joints in concrete floor slabs see figure 6.
0 51 mm since water repellent coatings can effectively resist water penetration for cracks of this size.
Joint spacing that is greater than 15 feet require the use of load transfer devices dowels or diamond plates.