Construction joints are normally required in construction works because there is limited supply of fresh concrete in concrete batching plants in a single day and the size of concrete pour may be too large to be concreted in one go.
The number of construction joints in concrete structures should be minimized. If construction joints are necessary to facilitate construction, it is normally aligned perpendicular to the direction of the member. For beams and slabs, construction joints are preferably located at about one-third of the span length. The choice of this location is based on the consideration of low bending moment anticipated with relatively low shear force. However, location of one-third span is not applicable to simply supported beams and slabs because this location is expected to have considerable shear forces and bending moment when subjected to design loads. Sometimes, engineers may tend to select the end supports as locations for construction joints just to simplify construction.
This question is taken from book named – A Self Learning Manual – Mastering Different Fields of Civil Engineering Works (VC-Q-A-Method) by Vincent T. H. CHU.
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Can we put the construction joint on 1/3 of slab (precast + insitu)?
Yes… Its done.. But let us know the reason
I am in need location of construction joints in foundation raft of 47.04X15.49 met.
Can we provide construction joint in slab/beam at 2/3 rd of span..?
can put construction joint at one per third span ofa car park’s rc ramp?
can we provide construction joint in raft
Is there a simple means of determining the width of an expansion joint in a building structure
How long must a building structure be before introducing an expansion joint.
but as per ACI 318-08 paragraph 6.4.4, it should be at the middle third of beams or slabs.