I save the sludge when I am cutting brick. I have 3 5gl buckets full of brick dust to use in lime plaster, 2 red and 1 yellow.

 

As an alternative to brick dust, try metakaolin. Concrete Supply places should have some.

 

speaking of mixes...whats your fave mix not involving fiber?(stucco)

 

Even though I have a bag sitting here, I have not used it. I am waiting until I need to do a white stucco. Generally I like NHL 2 unless the area is exposed. I vary aggregates alot:marble, granite, and of course sand.

 

You are obviously talking about a little more complex stucco mixes...

However I have to admit only time I tried course sand(other two worked out successfully) mix I failed miserably...

Thankfully it was obviously not customer's house.

 

It's interesting that the NHL 5.5 contains up to 30% clay and only comes up with a comp strength of 800psi, yet OPC contains as little as 33% clay and yields a comp strength of over 2000psi.

 

Way I always understood it, you can make "lime putty" from bagged hydrated lime....but that it was not quite the same as true lime putty. Meaning, that if I open a bag or more, fill a barrel or a buckets with the powder, add water and mix, leave sit overnite or over a week with standing water cover the lime mix, that it will not truly have the *quite* same preoperties as traditional lime putty.

Strengthe will be even less than the true historic mortars....


I'd love to be prooven wrong though!

 

When they make bagged lime, the crush and burn pure calcium carbonate, CaCo3. they then run it through a a conveyor belt with steam or a water mist hitting it. This makes the powder go off some but not all, enough so that it's not volatile anymore at least and its still a powdered form. When they make putty, they take chunks of CaCo3, burn it then throw it in water. Extremely violent reaction (hydration) occurs. After it cools the lumps are putty. So no it won't be exactly the same but it will be extremely close and since most of the hydration hasn't occured yet when it's in the bag it should still have lots of setting to do in the wall.

But I'm no chemist either so don't take my word on it.

Italian, he said "of course" sand. Not coarse sand. hahahaha.

 

Italian, he said "of course" sand. Not coarse sand. hahahaha.

I just realise that...i am like wtf...:laughing:

When I was doing stucco alchemistry in basement that particular one would NEVER work out lol :laughing:

 

lime

STUART45 IMHO you were spot on in your previous post. I have stated the same points in some discussions in this forum. It is my understanding that if the volume of opc is less then 50% of the cementious material in the mortar it has a detrimental effect on the overall quality of the mix. In other words do not guage a lime mortar with portland hopeing to create a mortar with the qualities of a hydraulic lime.

 

STUART45 IMHO you were spot on in your previous post. I have stated the same points in some discussions in this forum. It is my understanding that if the volume of opc is less then 50% of the cementious material in the mortar it has a detrimental effect on the overall quality of the mix. In other words do not guage a lime mortar with portland hopeing to create a mortar with the qualities of a hydraulic lime.

Well it certainly doesn't have a detrimental effect. the mortar can still be made to be less hard than the unit. And from that article, the portland fills the pores in the lime mortar stopping it from being AS permeable. But it doesn't say that a mix with only 5% OPC is less permeable than a Type N Lime/portland mix. I KNOW that that isn't true from pouring water on the 2 mixes and watching the water dissappear. All it's saying is that a hydraulic lime mix of the same strength is more(a lot more???) permeable than the same mix made with portland and lime.

 

lime

STUART45 I have been waiting for close to a year,my order for LIME& OTHER ALTERNATIVE CEMENTS by Wingate is backed up. I am anxious to read the info. on pozzalons. Perhaps you can help,do you have contact info. for HEPWORTH REFRACTORIES LTD.? Once they were bought out by the ALPINE GROUP i lost all ways to contact them. They produced a brick dust pozzalon. Does anyone know how to buy in U.S.A.? Thanks.

 

STUART45 I have been waiting for close to a year,my order for LIME& OTHER ALTERNATIVE CEMENTS by Wingate is backed up. I am anxious to read the info. on pozzalons. Perhaps you can help,do you have contact info. for HEPWORTH REFRACTORIES LTD.? Once they were bought out by the ALPINE GROUP i lost all ways to contact them. They produced a brick dust pozzalon. Does anyone know how to buy in U.S.A.? Thanks.

The site they were on was bought by Bovis a few years ago with the intention of building 500 homes on it.

 

lime

DOM MAS By detrimental effect the reference did not pertain to a ny property that i know of other then it negates the lime to work as a binder in the mortar.Having said that, what strength would a mix with 5-10- or even 20% have?

 

DOM MAS By detrimental effect the reference did not pertain to a ny property that i know of other then it negates the lime to work as a binder in the mortar.Having said that, what strength would a mix with 5-10- or even 20% have?

From reading that link that Stuart posted, the problem seems in the permeability of a lime mortar with a cement content. the Portland migrates into the pores of the lime/sand. So the lime mortar ends up being less porous and doesn't allow water vapour out as well as a pure lime mortar. That article says nothing about autogenous healing being effected, nor about lime no longer being a binder, only about the finished mortars permeability.

To my mind a high ;lime content has 3 major advantages and 1 minor over a modern masonry
cement mix.

1 it's generally weaker than the masonry unit

2. it more permeable than a masonry cement mix so even if liquid water gets in, water vapour can get out, without the need for idiotic weep holes.

3. A lime mix is more flexible and plastic

4. (minor advantage) autogenous healing. this only applies to hair line cracks and isn't always going to happen. It still needs a reasonable amount of heat, pressure, water and CO2. The large cracks that aren't tended too will allow so much more liquid water than many hairline cracks.

so #2 is compromised by the use of Portland as an additive but the other 2 major advantages remain as does the 1 minor advantage.

If you have any info that goes against my thinking I'd love to read it. I'm always interested in learning more about mortar.

As for what strength a mix with 5% would have, I would guess somewhere in the 100psi range, and 20% would be in the 400psi range. Compressive strength means nothing to me. I wish I had tagged the site but it was from an American Ivy league University. They had old articles from the 1880's-1920's all about new machines for making brick to different fuels for burning lime and brick etc.. Now remember that this was around the time that Portland was being introduced full steam. Some did a modulous of rupture test on pure lime mortars using real life walls, 2' thick. The mortar was tested to be around 75psi yet the wall withstood all the weight they could give it, I think it was in the multiple 1000's of PSI. There was a bunch of science physics that I didn't fully understand to explain why this was occuring but it explains why cathedrals that are a hundred feet high (so the lower mortar has 10's of 1000's of lbs bearing) and they have stood for centuries. And the ones that haven't, usually failed as they were being built, or very shortly after, being design flaws, not mortar problems.

 

Today I got prices for Eclogic mortar. Its a little pricey but I think its what the owner would like.

The salesman suggested possibly doing a mortar analysis but is 95% sure a building from that era would be a all lime mortar.

I plan on presenting an estimate the first of next week. I'm thinking I should figure a little more time for lime mortar than I would if tuckpointing with a regular type N mix....yes or no?

Thanks for the response...

 

Lime mortar needs two weeks cure before freezing. In the summer you have to watch it doesn't dry out too fast or it won't cure properly. Spring and early fall are the ideal seasons to repair with lime mortar. The pointing process is the same, but the cure time is critical and takes more management.

 

wazez.
These pages from an old book on building with lime might help.

 

The purpose of gauging a lime mortar is to force a quick set. 5-10% is not going to reduce the permeability enough to make the mortar/plaster non-breathable.

 

Did you read Stuarts post? According to that study, as little as 5% Portland did in fact effect the mortars permeability. How much was not answered.

I know that I have done type O mixes using portland and they have sucked up (So i would also assume release) water sprayed on it WAY faster than a type N mix using masonry cement.

I believe way more in the ability of the mortar to breathe than i trust weep holes due to opening up so many walls that are over a century old that are bone dry in the air space even though there are no weep holes. Now these are, I believe, pure lime or feebly hydraulic limes at best. But I have done my own very non scientific observations on the various mortars I've used and invariably, the lower the Portland content, the faster the visible water disappears. I have never used a hydraulic lime however.

 

lime

STUART45 I recognize those pages,they are from one of Wingate's books. The concepts of OPC negative effects on lime mortars may be in that book,or one by A.D. COWPER. I 'am not sure which. The effects i read that were real concerns of the authors were----amounts no matter how small bound up the lime and left no "free" lime to allow autogenous healing,therefore that property was a myth inthose mortars. Again,a very small amount prevented the lime to contribute any binding properties to mortar. That is why COWPER took a very dim view of any lime that did not have a hydraulic property on its own.AS a result wingate frowned on the idea of "guaging" a lime mortar with any OPC. The permability if i recall was not discussed at length,and seemed almost a non issue.

 

I'll have to see if I can find those books. But i can not see how lime could ever stop being a binder. It still takes up space between the sand and it still reacts and sets up, so it still acts as a binder. And the lime is still going to be sucked into the masonry units no matter, and iff the very small amount of OPC does displace the lime that is in the units then it won't be in the rest of the mix to stop autogenous healing or effect permeability. When I've removed soft mixes that I've made, it has certainly seemed like there is a lime content attached to the units

 

There is a paragraph.

 

There is a paragraph.
View attachment 66035

Starnge. I've used a 1;2:9 mix often and it is not weak at all, weaker by a fair bit compared to a 1:1:6 mix but a lot stronger than the pure lime mixes that I see in restoration. I also worked for the masonry division of the Canadian federal government for 8 months. During that time they did a study on a new sandstone to replace the stone at Parliament and many other federal building which is no longer being quarried. They used a 1:2:8 mix to build mini walls using this stone, then put it in a freezer and subjected it to 100+/- freeze thaw cycles. The stone and mortar both came out favourable. They also built a real wall at the NRC (Natioanl research council) so that it could be observed in real life. 5 years later it was observed and found to still have a decent modulus of rupture (I can't give you any #'s)

I'm no scientist but i can not see any way that an addition of portland would stop lime from carbonating. If CO2 can get to the centre of a wall after 40 years it can get passed 2" of re-pointed 1:2:8 mix.

Again, I'm absolutely not a scientist. I will look at that on-line book, maybe my mind will be changed

 

Lime

DOM MAS Check out the site of DeGRUCHY limeworks posted,Andy wrote about some of this in a newspaper interview.You can read the books of Michael Wingate,and old books by Cowper that are availble in reprints offered by Amazon.There is enough to keep one busy for quite long.Enjoy!

 

lime

STUART45 Thank you fo jumping in with the pages of the book! You are so much more adept with this machine(computer) then me. I just barely know were the on/off switch is ,could never in a million years figure out how to post a picture. Thanks again for your spot on help!

 

I would not consider a 1:2:9 mix to be a lime mortar/plaster.

 

Sorry, i never remember which comes first, lime or portland. I meant 2:1:8 or 2:1:9

No i was right the first time, 1:2:8 or 9 I would consider anything that has a lime content significantly higher that the portland content to be a lime mix with a Portland additive, No wait I was wrong, I find it very confusing. Any way I'm talking about a type O mix

Took a look at degruchy's article. i wonder if he couldn't have mentioned St. Astiers lime more often. Saying something is detrimental means nothing to me. Saying there is a salt content in portland is true of the cheap stuff, but there would also be a salt content in any natural limestone, even marble, as well as in most waters. Very few things in nature are pure, and salts are very common.

And as I said earlier, in my opinion, autogenous healing, while certainly a desired effect is not a be all and end all of a good mortar. A large crack (meaning one that I could just squeeze a piece of paper into) will introduce way more water and deeper, than a dozen hairline cracks that may or may not repair themselves given the proper conditions.

I'll see about those other books but so far the only thing that means anything to me so far has been Stuarts post about the lack of permeability, though they didn't give any hard #'s

 

If anyone is interested, the NRC test can be found at
http://www.nrc-cnrc.gc.ca/obj/irc/doc/pubs/nrcc47719/nrcc47719.pdf

And i was wrong, the study was about cold weather performance and protection. And the max feeze thaw was 57 days/cycles.
If anyone does take a look, I cut all those little squares of stone. Boring 2 days.

 

lime

DOM MAS I do not think the concern of lime carbonating in the center of the wall is the concern. Ithink the authors concern is the mortar that contains the portland in a volume less then the 50% as the book stated.

 

Ok, what i was trying to say is that IF CO2 can find it's way to the centre of a 4' wall after maybe 10 years, it MUST be able to find it's way to the lime that is only 2-*" deep in a typical repoint

Any way on to hour 2 of hydraulic lime/fat lime/pozzolano/portland research

 

If it has more than 10% gauging material then it is not a lime mortar.

 

says who? Maybe your right and maybe it's just a high lime mortar

 

mortar

DOM MAS Just read the paper you posted. Some interesting stuff. Thanks for taking the time to do that. One thing that came to mind was the tapping of the units with mallet & trowel. For years masons encouraged the mortar to be soft enough to bed to line with hand pressure only.The tapping to line with trowel was frowned upon. A number of years ago a engineer i believe from TX. encouraged the tapping with trowel. Her testing found that just one light tap increased the tensile bond strength between units over 50%! If memory serves, her name is Christine Beall or something similar. Just some trivea.

 

DOM MAS Just read the paper you posted. Some interesting stuff. Thanks for taking the time to do that. One thing that came to mind was the tapping of the units with mallet & trowel. For years masons encouraged the mortar to be soft enough to bed to line with hand pressure only.The tapping to line with trowel was frowned upon. A number of years ago a engineer i believe from TX. encouraged the tapping with trowel. Her testing found that just one light tap increased the tensile bond strength between units over 50%! If memory serves, her name is Christine Beall or something similar. Just some trivea.

it's interesting also that I know exactly the 2 masons who did the 2 different walls (prisms) One went to the same school as i did except 2 years ahead. The other was field trained by excellent masons and had been in the heritage division since it's formation 20 years ago and is now one of the heads of the division. i wonder which was which?