ASR Mitigation in Concrete 2

[magee913]

Hello,

I am currently a field engineer and we are pouring foundations in which the the supplier is using 20% class f fly ash to mitigate ASR. THe back up plan is to use lithium nitrate. Currenly their mix will use 542 lbs cement and 141 lbs class f fly ash. In the case of the back up plan, do they use 542 lbs cement, 141 lbs class c fly ash and lithium nitrate? THe back up plant is unable to hold class f so that is the reason behind lithium nitrate. Our specs state that class f or lithium nitrate must be used to mitigate asr

 

[Ron]

Yes, the lithium nitrate can be used in conjunction with fly ash.

Your portland cement percentage is still a bit high to mitigate ASR. You might consider using ground granulated blast furnace slag cement (GGBFS). While you will get a retarded strength gain (as you will with fly ash also), it will help quite a bit with the ASR issue.

 

[bimr]

Lithium is in addition to fly ash. See Specifications for Using Lithium to Control ASR in Concrete, Table 7 in this link:

http://www.fhwa.dot.gov/publications/research/infrastructure/pavements/pccp/03047/03.cfm