B Beeson wrote:This method was also called béton, béton coignet, or béton aggloméré:
1:3:6 proportions of...
hydraulic lime:silica sand:broken bricks
Hydraulic lime is not the same as pure Calcium Hydroxide. It has additional ingredients (pozzolans), that react to form the hardening agent.
Andrew Sul wrote:There is a lot of confusion in the US about working with lime. I think this partially stems from the some of the terminology in the industry. In America, when you walk into a big box builders store (Home Depot, Lowes, etc) you can buy sacks of hydrated lime. These sacks are really meant as plasticisers for portland cement mortar mixes. Masons add it to their mortar mixes because it improves the workability of the mortar creating a "fat" or "buttery" mortar. The lime itself has very little to no cementious properties. It will not act as a binder...
...So basically, by european standards, our limes are feebly hydraulic because they have little cementious properties. You would get a stronger wall by using a sand/clay rammed earth system. Of course, you can always use portland cement in your mortar if your heart is set on stone but lime alone won't do the trick. If your wife insists on using portland cement, at least consider lightweight foamed concrete. It's easy to make and very versatile. Again, more popular in Europe than the States. Good luck.
Simon Malik wrote:
I'll look-up lightweight foamed concrete. Can you recommend any DIY resources ?
Andrew Sul wrote:
This guy is doing some interesting work with foamed concrete:
His foam generator is a bit expensive but it does work well. I made mine for $0 out of stuff that I scrounged from my scrap pile so if you are on a tight budget, you can just cobble one together.
. I have made lime mortar from lime bought at home depot, and it is still strong.
Mix sand and lime together, wait a couple of months and you'll be able to crush your test cylinders with your hand
Andrew Sul wrote:I know this is confusing so here is a nice summary of the different types of limes available to consumers:
A quote from the above source: