Non-Shrink Grout Shrink distance
Non-Shrink Grout Shrink distance
(OP)
I let Sika recommended installer put non-shrink grout under the 10mm gap base plate. They sealed the formworks and put hose into it and pumped the grout using a large floor based cement pump. They know it's full when every side overflows as seen from above. Sika 215 is required since this is pumpable.. not Sika 212. Procedure looked ok. I'll know in two days when I removed the watertight formwork..
However something worries me. The concrete surface is not pre-wet.
Now supposed the dry concrete absorbs the water from the non-shrink grout. Would the non-shrink grout shrink? What's the distance it would shrink and sink. how do you compute for it? I'd like to know if the 10mm gap just becomes 9.99 with 0.01 shrink distance or even larger??






RE: Non-Shrink Grout Shrink distance
RE: Non-Shrink Grout Shrink distance
They don't know how to compute for the shrink distance. The installer doesn't seem to put importance into prewetting. Fortunately (depending on the theoretical and method of computation). It rained hard 2 days before the pour. However it's covered with base plate but some rain managed to touched the side of the column and some open holes (in some base plates).. so can the concrete absorb the rain at the side by capillary action, how much can it reach inside perpendicular to the side?
For Sika 215 with about 8000 psi final strength. I just need 300 psi. So don't mind any strength reduction as long as there is no gap and it doesn't shrink enough for any bolt to go into tension at yield strength or concrete pullout.
RE: Non-Shrink Grout Shrink distance
RE: Non-Shrink Grout Shrink distance
But if the dry concrete has absorbed the water in the non-shrink grout.. the non-shrink grout may sink.. and when it does.. it's like you didn't put any because there is no compression block and the tension bolts may be stress.
Therefore I need to know the shrinkage distance in the event computation support it, I can hire anchor experts to design post-in-anchor bolts that can also act as compression block, etc.
The raining 2 days before is just to let me feel better.. but then it is very sunny next day and the water in the concrete microstructure has already probably evaporated so let's assume dry concrete condition.
RE: Non-Shrink Grout Shrink distance