Pouring of grout along height

[BECT]

hello experts,

I am working on a project where we have to pour sika 212 HP grout behind a C Shaped steel plate and existing concrete. The concrete is also cut in the form of C shape . The void between Steel C shape and existing concrete wall is approximately 25mm. The pour height is approximately 8000mm. Considering its 8000mm high pour we decided to go with 1m/hr as grouting rate. Per the technical data sheet( TDS) the grout final set time is approximately 7 hrs and its not telling me initial set time . But similar sika product sika 212 TDS says initial set time between 4 to 5 hrs.

Once we are done pouring 1m of lift height, our plan is to prepare new batch of grout and pour the second lift after 1 hr. Considering my pouring rate is 1m /hr I don't think I should be running into the problem of cold joint at every lift.

Really looking forward to hear from experts of this forum their opinion.

Regards

 

[STrctPono]

Seeing as the gap is only 25mm wide, it seems as if the material is not structural in nature but rather filling a void between two objects. Perhaps this material is providing bearing support between the C-Shaped Steel Plate to the existing concrete. With that understanding, I would not be concerned about a "cold joint" forming. However, I don't think that you will have a cold joint form. With 7 hour final set time, your initial set time will not be as soon as 1 hour so as long as you pour your 2nd lift before that, I wouldn't think that would even be a concern. You could even hit the front face of C-shaped plate with a percussion tool as you go to pour your 2nd lift to reactivate the 1st lift in case it did stiffen a bit.

 

[r13]

You should try a small batch and measure the time that the grout remains workable/plastic. Also, I think you will need device some kind of vibration to avoid weak plane forming between lifts.

 

[BECT]

Thanks " STrctPono" . Sounds like I am on the same page with you.

Thanks "retired13" . I already ask site team to do initial set time test using "vicat apparatus" . They came back telling me that under the site condition the initial set is approximately 5hrs and final set is around 7 hrs. So looks like and as "StrctPono" mentioned in his response it won't be an issue as I have big window here.

my C shape is continuous 8000mm in height and we have 3 grouting ports , 1 on each face of C shape and are spaced 1m interval along the height. we will pour through one of the ports and will witness the grout coming through the second and third port as our QA/QC check that material is flowing on all the sides. we are just planning to do little tapping on the plate where 2nd lift is coming in contact with first lift to send some vibration.

 

[r13]

Sounds a well thought setup. Good luck.

 

[SlideRuleEra]

The void between Steel C shape and existing concrete wall is approximately 25mm.
...C shape is continuous 8000mm in height...
...pouring rate is 1m /hr...
...under the site condition the initial set is approximately 5hrs and final set is around 7 hrs.

Is the plate anchored securely enough to resist the hydrostatic pressure of fluid grout that may be a few meters deep?

http://www.SlideRuleEra.net

 

[BECT]

Yes it is.

 

[SlideRuleEra]

Very good, and well planned.

http://www.SlideRuleEra.net

 

[r13]

In addition to tapping the form, I'll use a small smooth rod to ensure there is no air bubble blocking the flow, as flow out from the higher vents may cheat. Track the volume has been placed at certain interval, it can help you in trouble shooting.

 

[BECT]

Excellent Point " retired13".