Went to break test them today...broke both with my hands...
What was the recipe?
If you can break the material by hands it surely does contain not polymer chains and tetrahedron /octahedron structures
Maybe the belows' words of Davidovits will explain the low structural strength of your mix
(Alkali Activated Materials are NOT Geopolymers - Part 3)
btw. Does any one know what happened to user Karl?
First recipe was for the "rectangle" brick:
LTGS
20% binder
10% Kaolin 6-tile clay
10% NaOH
80% Kaolin 6-tile clay
1:1 clay to slag ratio
I mixed up a 200g sample...
1) took 20g kaolin 6-tile clay and acid activated with 5% concentration vinegar (needed 5% of 20g or 1g acetic acid - 20g of vinegar)
2) took 160g kaolin 6-tile clay and acid activated with 5% concentration vinegar (needed 5% of 160g or 8g acetic acid - 160g of vinegar)
3) I let the acid/clay mix rest overnight (8:00 PM - 4:00 PM the next day - 20 hours total)
4) to the "binder" mix of 20g kaolin 6-tile + 20g of vinegar I added 20g of NaOH...during the "resting period" of 2 hours (that I came up with arbitrarily) it started getting pretty thick, so I added 2mL of water and mixed it in.
5) after the 2 hour (arbitrary amount of time) "resting" period, I mixed together the "binder" (acid activated clay + NaOH) and the remaining acid activated clay.
6) I then mixed in 180g of slag sand (my 1:1) ratio of clay/slag
7) I then mixed in 18g of hydrated lime (10% of the clay by weight)
I have made a vibrating table after watching the you-tube videos that Karl and others have shared, so I put the mix in a plastic mould and let it vibrate on the vibe table until it settled into the mould (it vibrated into the mould pretty well).
I let the mix set in the mould for 4 days in my basement to "solidify" during which time it experienced a fair amount of shrinkage.
After the 4-day (arbitrary) solidifying time, I made the make shift "warming chamber" and started to "dry out" the brick using some small candles as the heat source...I left them in the "warming chamber" for 6 hours.
The next day, I "camp fire cured" them for 3 hours...the first 1.5 hours around the edge of my fire ring, then the last 1.5 hours right near the burning wood and coals.
The following day, I "strength tested" them which means that I tried to "bend them in half". As you saw, this brick broke...
Second recipe was for the "round" brick:
LTGS
20% binder
10% Kaolin 6-tile clay
10% NaOH
80% Kaolin 6-tile clay
1:1 clay to slag ratio
I mixed up a 200g sample...
1) took 20g kaolin 6-tile clay and acid activated with 3% concentration vinegar (needed 3% of 20g or 0.6g acetic acid - 12g of vinegar)
2) took 160g kaolin 6-tile clay and acid activated with 3% concentration vinegar (needed 3% of 160g or 4.8g acetic acid - 96g of vinegar)
3) I let the acid/clay mix rest overnight (18 hours total)
4) to the "binder" mix of 20g kaolin 6-tile + 12g of vinegar I added 20g of NaOH...during the "resting period" of 0.5 hours (that I came up with arbitrarily) it started getting pretty thick, so I added 6mL of water and mixed it in.
5) after the 0.5 hour (arbitrary amount of time) "resting" period, I mixed together the "binder" (acid activated clay + NaOH) and the remaining acid activated clay.
6) I then mixed in 180g of slag sand (my 1:1 ratio of clay/slag)
7) I then mixed in 18g of hydrated lime (10% of the clay by weight) + 4 mL of water
I put the mix in a plastic mould and tried to vibrate it on the vibe table, but it was too thick so I had to press and spread it into the mould with my hands.
I let the mix set in the mould for 2 days in my basement to "solidify" during which time it experienced a fair amount of shrinkage...less shrinkage than the rectangle sample, but it was also only allowed 1/2 of the time as the rectangle brick to solidify (2 days vs. 4 days)
After the 2-day (arbitrary) solidifying time, I made the make shift "warming chamber" and started to "dry out" the brick using some small candles as the heat source...I left them in the "warming chamber" for 6 hours.
The next day, I "camp fire cured" them for 3 hours...the first 1.5 hours around the edge of my fire ring, then the last 1.5 hours right near the burning wood and coals.
The following day, I "strength tested" them which means that I tried to "bend them in half". As you saw, this brick broke...