Thixotropic Additive

I'm looking for a thixotropic additive for portland cement mortar. I need to be able to pump it with a mono pump about 20 metres then have
it gel on release. Any ideas?
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
snipped-for-privacy@bmail.com.au wrote:

I suspect you mean pseudoplastic.
http://en.wikipedia.org/wiki/Non-Newtonian_fluid http://www.brookfieldengineering.com/education/what-is-viscosity.asp
I suppose you could look at adding fumed silica and a polysaccharides like Xanthan gum. Also an addition of bentonite may help. I think a major issue is how the additives will affect the setting behavior and final strength of the cement. Moyno "progressing cavity" pumps tend to be low shear - but with high solids content mortar, you may get enough action "internal shear" to break down the gel during pumping and hope the gel does not have time to rebuild until it hits the target - or have just the right gel strength to allow it to flow in whatever system your working with (I suspect this would be tricky to achieve with out a lot of specific knowledge about your system). There are probably polymer additives that should be tested as well.
good luck - I wish I could provide information that was more specific..
Gregg
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

http://en.wikipedia.org/wiki/Non-Newtonian_fluidhttp://www.brookfieldengineering.com/education/what-is-viscosity.asp
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

http://en.wikipedia.org/wiki/Non-Newtonian_fluidhttp://www.brookfieldengineering.com/education/what-is-viscosity.asp
Thanks for that Gregg. Fumed silica is a bit of a problem in Oz due to particle size. OH&S dpartments really frown on it despite the non crystalline nature. Clay additions to any cement systems are also a worry due to the calcium silicate scums that form but the polysaccharides might be the plan. I've tried some of the water soluble methyl cellulose products but with limited success, but I shall struggle on. Thanks again
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Polytechforum.com is a website by engineers for engineers. It is not affiliated with any of manufacturers or vendors discussed here. All logos and trade names are the property of their respective owners.