Sand Equivalent Test Vs Silt Content Test - Concrete Durability

[Contech2011]

Hi,
What is the difference between sand equivalent test values and sa simple silt content test?I mean when you finish a SE test, specs say that min 75% SE value is accepatable, which means max 25% of clay/silt content is acceptable limit for sand used in structural concrete! But other specs say silt content more than 8% in sand would ruin the concrete strength by more water demand.Is SE value of 75% min is a reasonable value for sand to be used in concrete?In silt content test we just add salt solution to sand until its immersed and keep it undistrubed for 3 hrs. Silt height & sand height is then read. Silt Content = Silt ht/ Sand ht x100.Please comment

 

[ACtrafficengr]

I've never heard of using the SE test for anything other than subbase base aggregate, and even then, it's considered a field expediant check, not a replacement for a good gradation test.

Maybe the tyranny of Murphy is the penalty for hubris. -

http://xkcd.com/319/

 

[sleterzman]

http://www.pcts.com.au

has information regarding non-destructive testing of concrete should you ever need it. Sorry I can't be of more help.