FE_struct1
Structural
- Nov 30, 2017
- 41
Hi all,
I've noticed that in the 2018 code the 30 year shrinkage strain values for 80 and 100 MPa concrete mixes are significantly larger than those in the 2009 code. Referring to table 3.7.1.2, for th = 400 and Tropical environment, the 2018 code recommends 500 microstrains - nearly 50% greater than the 2009 code recommended 340 microstrains (the difference is actually higher since the base drying shrinkage used to make the table is smaller in the 2018 code than in 2009). This increase is exacerbated for smaller values of th.
I've done a back of the envelope comparison with CEB-FIP 2010 and while the 2009 code was in the same ballpark as FIP, the new one is quite off (image attached)
Can anyone advise on why there is such a large increase in shrinkage for the new standard ? I've looked through Gilbert's research online (I assume he was the driving force behind this ?) but haven't found anything to explain the change.
I've noticed that in the 2018 code the 30 year shrinkage strain values for 80 and 100 MPa concrete mixes are significantly larger than those in the 2009 code. Referring to table 3.7.1.2, for th = 400 and Tropical environment, the 2018 code recommends 500 microstrains - nearly 50% greater than the 2009 code recommended 340 microstrains (the difference is actually higher since the base drying shrinkage used to make the table is smaller in the 2018 code than in 2009). This increase is exacerbated for smaller values of th.
I've done a back of the envelope comparison with CEB-FIP 2010 and while the 2009 code was in the same ballpark as FIP, the new one is quite off (image attached)
Can anyone advise on why there is such a large increase in shrinkage for the new standard ? I've looked through Gilbert's research online (I assume he was the driving force behind this ?) but haven't found anything to explain the change.