Further to a previous discussion (
), I have a couple of extra questions regarding the RAM ECR/Load History parameters.
1) The RAM Manual describes the Creep factor = Total Strain / Elastic Strain = (Elastic Strain + Creep Strain )/Elastic Strain.
communities.bentley.com/.../6191.ram-concept-load-history-calc-options-tn
The above discussion deals mainly with the creep co-efficient in the AS3600 and inputting that as the creep factor.
AS3600 - 1.6.3.17 defines the creep co-efficient as the ratio of the creep strain/elastic strain.
As such, the creep co-efficient is not directly comparable to the RAM creep factor. For a creep co-efficient of 2.23 (28 day initial load, 200 thick, 40MPa and Temperate inland), shouldn't the creep factor = 1 + 2.23 = 3.23??
2) For the Shrinkage strain parameter, I understand that RAM applies a modification for an ACI 209 moist cure duration other than 7 days (which is determined by what the user inputs into the Moist cure duration field).
However the AS3600 shrinkage strain calc does not have a clear factor for the "moist cure duration". The points in time that are used are:
a) the time after the "commencement of drying" (for drying shrinkage)
b) the time after "setting" (for autogenous/endogenous shrinkage)
Can you provide an idea of what points in time the ACI 209 "moist cure duration" is referring to (eg. from pouring to "setting"? from pouring to "commencement of drying"? from "commencement of drying" to "setting"? or otherwise?). It would be good to know that the moist cure duration field is not being incorrectly used along side AS3600 shrinkage strain value.
Thanks in advance.
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RAM ECR parameters
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