Using lake or river water to mix cement

Started by cbc58, March 12, 2017, 08:39:00 AM

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cbc58

Any concerns with using lake water (or river water) to mix cement for structural piers ?   

Redoverfarm



Don_P

I was writing slow  :)

"Don't use water you wouldn't drink" By which they mean don't use muddy, acid or alkaline, oily, turdy or dirty water. Cement is undergoing a chemical reaction, it has to be able to grow crystals that lock the clean aggregate together to form concrete.

Frank Lloyd Wright was a hands on kind of architect and was often directing the workmen on his projects. He liked to incorporate natural materials from the site, admirable. For whatever reason this extended to throwing a few shovelfuls of the native dirt into the mix as they were making the concrete on a number of his jobs. That has lead to spalling on several of his homes.

I was looking at the foundation of an old gas station here a few weeks ago. Although I never met Mac I know his work from multiple buildings spanning from about 1910-1960. He understood how to build a foundation, his buildings are much easier to maintain and repair than average because they haven't been tearing themselves apart. This one must have been an experiment or done on a shoestring. The concrete is spalling pretty badly. It is a lean looking mix with what looks to be smooth sand from the creek below. The aggregates need to be sharp with enough cement paste to bind and coat them well. It serviced model T's and is still standing with trees growing through old farm implements  around it, so it did serve the purpose long and well enough. He also tried his hand at building 30' monoslope trusses. The repairs there show that he understood the concepts but didn't have the details hammered out.

flyingvan

A relative is building in Baja and wants to use salt water to mix his concrete.  First reaction was 'no way' then looked into it a little more.  Here's one of many articles on the subject--- http://www.monolithic.org/blogs/presidents-sphere/salt-water-concrete-a-reality  The SeaBees have done it forever.  I would think lake water would be far superior to ocean water
Find what you love and let it kill you.

Redoverfarm

In some remote areas some have used all the resources from near by streams.  The sand was not really clean, using river gravel and stone.  Just a disaster waiting for age to catch up and start failing.

I was working near a foundation this past week and it was oblivious that this was their material list in that it had failed.  It was located near a river.  You could actually see the river rock.  The wooden house portion had since long gone.  But it could have lasted for years even with that accessible material as it was unknown when it was built.  But then again given the foundation It might have only been 50-75 years.

Oh did I mention not to use river rock near the fireplace opening. 


Adam Roby

In many rural areas the lake water is drinkable, so I'd assume if it won't kill you it might be OK for the mixer...  but I'm no expert.  Many of us only have that as an option, so I would suggest to get it as clean as possible (filter it as much as you can if its not perfectly clear).

glenn kangiser

My relatives used to use river or beach rock in their fireplaces, but they can explode so to select the good ones they would build a giant bonfire on the rocks and only use the ones that didn't explode in their fireplaces.  I assume they stood back as they remained to tell about it years later.  :)
"Always work from the general to the specific." J. Raabe

Glenn's Underground Cabin  http://countryplans.com/smf/index.php?topic=151.0

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Redoverfarm

Well the other day I had made mention of some older foundations that I had seen that had used river rock and probably river sand in their foundation mix.  I got a few pictures of how the concrete had not held up.  Come to think after I got to checking these foundations were probably built around the turn of the century. 

The first photo is an example of using what is available in a rural area.  Yes there is some rebar but mostly angle iron and probably bed rail.  The river rock is present in the mix.  The surface has severe spalling.



Severe spalling



Inadequate mix ratio.  Notice all the river rock at one location and the cement did not bond around the rock causing a weak point which had cracked and separated


NathanS

Devils advocate... are there examples of high quality concrete holding up better than this in similar environment? In the north east the freeze thaw will kill any concrete that gets wet and freezes at night. Sidewalks don't last long at all, and the long(er) lasting steps are going to be solid stone caps but even the bluestone wears away over time. The old expensive buildings (churches and gov't) would use granite or some similar stone for the bottom few feet that absorbed little to no water, then would switch over to brick or some more (cheaper) porous stone. Those foundations still look brand new, but even the bluestone window sills are wearing away. They would also use the good stuff on outside corners. I always notice the cheaper buildings (all brick, down to the ground) are wearing away big time.

When I was looking at old houses around here, the stone foundations are doing mostly fine, but the lime mortar is completely gone now.

Concrete is porous, water gets in during daytime rain, and then freezes at night and busts everything apart.

I think it's all about water control, big overhangs and gutters to try to keep the rain away. If you live somewhere that water doesn't freeze at night for a few months a year, none of this probably matters.


Don_P

You'll also notice throughout the world on older masonry, even in places that don't freeze but do get wet, that buildings may start out with soft brick or poorer quality masonry that the bottom bew feet of buildings, or the entire building becomes stucco, a wear coat that gets occasionally refreshed. We tend to replace buildings more often, although we also tend to use it in ways that call for replacement sometimes, not purely as a compressive material.

glenn kangiser

For many years there have been issues with Friant dam near Fresno, using local river rock that was slightly expansive causing a few weaknesses in the dam, but it is still there and there are still rock plants on the same river dealing the same rock so I guess it depends on how critical the use is.  :)
"Always work from the general to the specific." J. Raabe

Glenn's Underground Cabin  http://countryplans.com/smf/index.php?topic=151.0

Please put your area in your sig line so we can assist with location specific answers.

hpinson

#11
You are very likely just fine using river or lake water for piers. But in the interests of science...

If you live in areas where the water is very acidic, or at Alkalai flats like me, I would think that the base characteristic of the water could affect outcome. 

I see there is a lot of literature on controlling the alkalinity or acidity of the concrete mixture itself to different affect, and the water used could contribute a little or a lot. You are effectively changing the chemistry of the mixture, with attendant results. Also it can affect the longevity of the reinforcement, i.e. iron rebar, which can rot internally.

Some clear water, like in southern Ontario or upstate New York, is actually fairly acidic despite it appearing crystal clear.  And in the West, highly alkali water is very common to the point where the water appears muddy and the carbonate crystalizes out of any water left to evaporate. Just saw this Tuesday in Utah and I see it every year when cleaning out my swamp cooler.

Two references:

1. Properties of Concrete, by A.M. Neville (Free PDF)
https://igitgeotech.files.wordpress.com/2014/10/properties-of-concrete-by-a-m-neville.pdf

2. Concrete: Properties... by P.K. Mehta
https://www.amazon.com/Concrete-Microstructure-Properties-Kumar-Mehta/dp/0071797874