Heat of Hydration of Mass Concrete
Heat of Hydration of Mass Concrete
(OP)
Anybody aware of a way/equation/reference to calculate the temperature inside a piece of 'Mass Concrete'. Yes there are a lot of variables.
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Heat of Hydration of Mass Concrete
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RE: Heat of Hydration of Mass Concrete
The greatest trick that bond stress ever pulled was convincing the world it didn't exist.
RE: Heat of Hydration of Mass Concrete
Current problem is a chunk of concrete about 2.5' wide at the top and about six feet wide at the bottom. Vertical front face 7' high, sloped back face. the total length is 1300 feet with expansion joints every 70 feet. It ended up developing shrinkage cracks about every 6 foot o.c. about 2 days after the pour. I'm doing a structural condition assessment/forensic investigation.
This is definitely a thermal expansion problem during curing, compounded by the fact that the previously mentioned piece was poured on top of a previously poured foundation, so restrained at the base. The codes and literature tell you that you will get cracking if the outside temp differs from the inside temp by 20 degrees C, European is 19 deg C.
I'll take a look at what you sent and see if can figure out how to predict the core temp given the myriad of other variable. Thanks again.
RE: Heat of Hydration of Mass Concrete
The greatest trick that bond stress ever pulled was convincing the world it didn't exist.
RE: Heat of Hydration of Mass Concrete
RE: Heat of Hydration of Mass Concrete
The 20 deg is a temperature differential value above which cracking will occur in thick members due to internal restraint. In your case you also have external restraint due to it being poured on old concrete; that sort of restraint can be pretty high and can require a lot of reinforcement near the base to control crack widths. In the external restraint case the temperature differential doesn't matter as much as the drop in temperature from the max to ambient temperature as well as shrinkage of the concrete (as hokie mentioned).
Also as hokie mentioned: what are your crack widths? Might not be a problem at all