RMC roof concrete develops cracks in few hours.

[kumarraja]

Cracks have developed few hours after pouring RMC concrete.

[sandeeper]

Due to high temperature cracks are common during concreting .

[kumarraja]

Are these cracks dangerous for the structure ?

[ardesarchitects]

Hi ,
Cracks in the concrete are common when temperatures are high.you can sprinkle the water sparsely not much for first 4-5 hours .After 1-2 hour you need to tap the whole slab casting for better compaction .
After 8-10 hrs you can start curing by storing water on top of slab .
Cracks on the roof are not going to effect the structure in anyways ,please check for any heavy slurry leaks from centering to avoid honey combs

Regards
Ar.Praveen.N
Ardes Architects and Interior designers
ardesarchitects@gmail.com
https://www.facebook.com/ardes.architects
http://www.ardesarchitects.com

[kumarraja]

Dear Arch praveen,

What do you exactly mean by " tap the slab" ?

[sandeeper]

As u said cracks appeared in few hours after pouring concrete , so there is nothing to worry about structure .

[kvanbu]

Kumar,

You need to cover the concrete with tarpaulin(blue sheet) and sprinkle water immediately on the sheet if you are putting concrete when temperature is high (before 4 PM). After 4 PM is the best time to put slab concrete. Curing has to be started immediately after the bleeding water goes away. Bleeding water will not evaporate immediately in the evening. You need to sprinkle water if one can walk on that. I have used RMC for my G + 3 and there was no crack. I have followed above said curing method as instructed by RMC company. I did the concrete in the evening. I have added waterproof and fiber in the RMC for all my slabs.

Thanks

[kumarraja]

What is that fiber you are talking about ?
There is no RMC transit truck which can deliver after 4 PM when the traffic is at its peak, trucks not allowed to ply inside city.

[ardesarchitects]

Hi,
Tapping i mean mason takes his levling bar (matkol)and keep compacting rcc by applying pressure .


Regards
Ar.Praveen.N
Ardes Architects and Interior designers
ardesarchitects@gmail.com
https://www.facebook.com/ardes.architects
http://www.ardesarchitects.com