control joint in structural concrete 1

[rsavani]

Hi,

is there any Rules ot Design guidelines for control joint in concrete water reservoire design. Thickness of walls and slab is 300mm. That is in cold weathre expouser too.

thnaks for your time.

 

[msquared48]

Does the reservoir have an interior liner, or is it just a slab?

Mike McCann
MMC Engineering
Motto: KISS
Motivation: Don't ask

 

[rsavani]

yes it have concrete baffle walls, thick 250mm.size of tank is 16 X24 Mt.

thanks

 

[JedClampett]

Control joints are different than construction joints. Control joints have either no bars or greatly reduced reinforcing crossing the joint. They're troublesome for many reasons, but most of all the tendancy toward torn waterstop.
If you mean construction joints, the usual spacing is 30 ft.

 

[cntw1953]

Jed is correct, providing control joint is inviting trouble for project require water-tightness.

 

[rsavani]

Hi,

thanks for your time. I am not sure why engineer did control joint(thats the term they use on plan)on Base Slab of 16X24 mt, thick 300mm. that can be doable in one day or one pour.

control joint allow any movment in cocnrete. so is it any any voloumn replationship with tem. that governs location of control joint.

i agree with both, but i am tring to understand this issue technically in depth so i can prevent any further damange to public assest.

thanks,

rakesh

 

[cntw1953]

A construction joint is preferably located at low stress area, good bond between lifts is key to success. There are many more considerations when dealing with shrinkage compensation joint (control joint) as it is affected by factors such as structure geometry, lift volume, source and degree of restrains.

To me, unless it is necessary for sound reasons, joint should be avoid/minimized in water retaining structures. If it couldn't be avoid, proper preparation for specific type of joint and good workmanship hold the key.

This topic has been repeatly brought up in this forum, do a search you may find many more useful discussion/hints.

 

[dik]

Typical Control Joint...