Septic tanks and water pollution

From your engineers... Cracks happen, but isn't really the normal. They reduce the worst chance of getting cracks, and their impact on the project. Rebar prevents separation and movement. Consider a brick wall. You can simply stack the bricks, interlaced, and it will hold up fairly well, if you don't push on it. If you set the bricks in mortar, as you stack them, it's a very strong wall. The mortar holds the bricks in place, can't shift or move. That's really all rebar does, keep the concrete from being deformed, separated, and chunks moving around. Even if the cracks extend all the way through, which is unlikely, the rebar still holds everything in places. Still fails occasionally, but not that common, or it wouldn't be used so much. Sloppy work, and cheap materials is what usually causes such failures.

Xadoman wrote:

From your engineers... Cracks happen, but isn't really the normal. They reduce the worst chance of getting cracks, and their impact on the project. Rebar prevents separation and movement. Consider a brick wall. You can simply stack the bricks, interlaced, and it will hold up fairly well, if you don't push on it. If you set the bricks in mortar, as you stack them, it's a very strong wall. The mortar holds the bricks in place, can't shift or move. That's really all rebar does, keep the concrete from being deformed, separated, and chunks moving around. Even if the cracks extend all the way through, which is unlikely, the rebar still holds everything in places. Still fails occasionally, but not that common, or it wouldn't be used so much. Sloppy work, and cheap materials is what usually causes such failures.

Cracks are very normal in reinforced concrete. In tension zones the concrete has to crack in order to let the rebar to start doing its job. Concrete is quite weak in tension and beams and slabs would simply collapse without rebar. That is its main job nowadays - to compensate for the weakness in tension of the concrete.
A simple stacked brick wall is quite strong but it has its limitations. For example a basement wall without reinforcement needs to be quite thick to perform adequatly. A single layer brick wall would balloon and collapse under the lateral pressure caused by the soil/backfill. Those kind of walls need to be massive - prefeably 2 foot thick. The basement of my 100+ years old summerhouse is made of splitted fieldstone. Those walls are approximately 2 foot thick. The ceiling of the basement is the shape of an arch and is also made of fieldstones. There is also no rebar in the walls or ceiling. What amazes me is the complete lack of visible cracks in the walls. I think the mortar they used back then is more elastic than a simple cement mortar. They used lime mortar which is not as strong but more elastic than cement mortar.

Xadoman wrote:

Cracks are not inevitable.

Lets see what guys from eng-tips forum think about that( guys that design bridges and skyscrapers):

When can cracks occur? Any time after placement, depending on conditions. As hokie66 noted, there are two significant types of shrinkage cracking. The first and earliest occurring is plastic shrinkage cracking. This occurs while the concrete is still predominately in a plastic state and is caused by the surface of the concrete drying before the subsurface sets up. The most common cause of this issue is placing the concrete in windy weather. These cracks are usually short, discontinuous cracks that, because of the reduction in cross section they cause, then become connected as typical full section drying shrinkage cracks.

Most cracks occur very early in the curing process but may not be clearly visible for many days after placement. As the concrete continues to shrink with the hydration process, the cracks will widen and become more visible. The cracks will continue to widen with time. You should see most of the cracks that will occur in the placement within the first month.

Concrete cracks. Are there Crack Control Joints cut into the 12 x 25 slab? What is the thickness of the slabs that were poured. Were any test cylinders (for strength) taken? (I guess, probably not. ) Was water added to the concrete during the placement? What was the low temerature for the week after the pour? Were the slabs covered with poly or blankets? Was water or curing compound used?

No, it is not "like a beam". In a slab on ground, the force is applied as direct tension to the slab as the concrete shrinks, and the subgrade restrains this shrinkage. There are two ways of dealing with this type of cracking: 1) Use a lot of reinforcement, say 0.5%AG, which doesn't prevent the cracking, but controls the width of cracks; or 2) Provide control joints, which are also cracks, but nice and straight. The second solution is usually used in things like garages.

the only sure things in life are death, taxes, and concrete cracking. all concrete cracks are not created equal. Many are fine. This is why we have an entire technical field of concrete crack control.

Could go on like this forever.

GasGuzzler wrote:
No cracks in my driveway or garage slab. 17 years old. It has been exposed to -40F up 105F, frost around 50 inches, and a 7,000lb truck parked on it every day. Guess my concrete guys did something right.

HarveyH55 wrote:

Xadoman wrote:
James got it right. Harvey and ITN both deny reality for some unknown reasons. The main cause of the concrete deterioration is the rotting of the steel inside. It takes time but it is inevitable. As said even stainless steel rebar rusts in the concrete. Bridge decks are normally overhauled after every 25 years or so because the environment is aggressive as hell due to deicing salts.
A layer of rust does not protect iron for further corrosion. Just look at your car and see it for yourself how a little rusty spots turns to a hole quite quickly. Add some deicing salt from the roads in winter and the body will rot very quickly.
How do they protect rebar from rusting inside the concrete?

1. Concrete cover. 3 inch is recommended for concrete that is in contact with soil.
2. Galvanizing, sacrificial anode, epoxy , basalt, glass fiber etc etc

Also, I would just want to point out that concrete has to crack a little so that the rebar in it would start to work . I am not talking about pretensioned structures but about plain simple concrete beams and slabs that have been poured on site into the formwork. The beam or slab has do deflect just a little bit before the rebar starts to bite in and starts its job. Those are of course very small cracks or fractures like James said but those are inevitable. We are not living in an ideal world were cracks and defects are non existent. We have to deal with those problems that arise from non ideal world. Fortunately there are solutions and I use them.

No, James got it wrong... Even if concrete produce an electric current, it would be extremely small, and at a very low voltage. Oxidized surfaces are very poor conductors.

You both fail to realize that the rebar is sealed in concrete, the rust layer doesn't get removed or cleaned off, to expose more iron. The thin layer of rust, stays in place, no where to go. Rust exposed to the environment, continues to rust, because it flakes off, gets rinsed, or an abrasive, like sand removes it. Wind and vibration help too.

Electrolysis can also be used to remove rust...

From your engineers... Cracks happen, but isn't really the normal. They reduce the worst chance of getting cracks, and their impact on the project. Rebar prevents separation and movement. Consider a brick wall. You can simply stack the bricks, interlaced, and it will hold up fairly well, if you don't push on it. If you set the bricks in mortar, as you stack them, it's a very strong wall. The mortar holds the bricks in place, can't shift or move. That's really all rebar does, keep the concrete from being deformed, separated, and chunks moving around. Even if the cracks extend all the way through, which is unlikely, the rebar still holds everything in places. Still fails occasionally, but not that common, or it wouldn't be used so much. Sloppy work, and cheap materials is what usually causes such failures.

This is why I don't buy into global warming. It's paranoid-alarmist stuff, where they take something that's technically possible, on paper, if just the right conditions exist, and call it a crisis, spare no expense, to fix it. You aren't in a saltwater environment, but use those examples to support your corrosion panic. I know more about electronics and electricity, more than any other subject I've studied or worked with. A lot of stuff produce measurable electricity, but it's very low voltage and current, and of little potential to do much of anything. We have to chain a bunch of these together, to get sufficient potential to do any sort of work. A single solar cell will produce just 0.5 volts. We need to put a bunch of them in series, to get a useful voltage. Even then, there isn't much current, so we a add a bunch more in parallel. Your rebar in concrete, isn't electrically separated, and wired in series and parallel to get a sufficient potential, to get past the oxide layer, to perform electrolysis. The oxide layer is a very poor conductor, works as insulation on a wire. It's very high resistance. What happens on paper, or in ideal conditions in the lab, isn't the same as outdoors.

Xadoman wrote:

GasGuzzler wrote:
No cracks in my driveway or garage slab. 17 years old. It has been exposed to -40F up 105F, frost around 50 inches, and a 7,000lb truck parked on it every day. Guess my concrete guys did something right.

Did they made the sawcuts? If so then those are the cracks- controlled cracks

Xadoman wrote:
Also, most cracks are not so big that they are visible to eyes.

Xadoman wrote:
We can not see the coronavirus but we surely know what it could do.

Xadoman wrote:
17 years is also quite a short time even for a regular iron to start rusting in concrete.

Xadoman wrote:
Most bridges of reinforced concrete were designed to last approximately 50 years but they could outlast their desing life as time has shown.

Xadoman wrote:
With proper maintenance their life could be extended but eventually they should be demolished before they collapse. Unfortunately some of those have been collapsed before they have been taken out of service.

Xadoman wrote:
Harvey, the concrete is not a perfect sealant. It always has small little cracks in it which allow agressive elements( such as chlorides) to attack rebar. In real life the moisture will also get to the rebar through those tiny little cracks. The high alkanity of concrete( creating a passive layer over the rebar,) is what protects the rebar initially but even the alkanity of the concrete slowly diminishes over time through a process called carbonation. This passive layer protects the rebar. Somewhat like on the stainless steel there is a passive layer that forms and protects it from rusting. With stainless steel there are other problems. It needs oxygen to heal if the passive layer is destroyed. In concrete or in some tight fittings this could become a problem and the stainless could rust away very quickly.
You say you know about electronics a thing or two. I found a good video of how solar panels are saving the rebar in the bridge:
https://www.youtube.com/watch?v=Xc6NikRJDtg

I myself am not a big fan of solar panels but in this application they are quite awesome.

Xadoman wrote:

From your engineers... Cracks happen, but isn't really the normal. They reduce the worst chance of getting cracks, and their impact on the project. Rebar prevents separation and movement. Consider a brick wall. You can simply stack the bricks, interlaced, and it will hold up fairly well, if you don't push on it. If you set the bricks in mortar, as you stack them, it's a very strong wall. The mortar holds the bricks in place, can't shift or move. That's really all rebar does, keep the concrete from being deformed, separated, and chunks moving around. Even if the cracks extend all the way through, which is unlikely, the rebar still holds everything in places. Still fails occasionally, but not that common, or it wouldn't be used so much. Sloppy work, and cheap materials is what usually causes such failures.

Cracks are very normal in reinforced concrete. In tension zones the concrete has to crack in order to let the rebar to start doing its job. Concrete is quite weak in tension and beams and slabs would simply collapse without rebar. That is its main job nowadays - to compensate for the weakness in tension of the concrete.
A simple stacked brick wall is quite strong but it has its limitations. For example a basement wall without reinforcement needs to be quite thick to perform adequatly. A single layer brick wall would balloon and collapse under the lateral pressure caused by the soil/backfill. Those kind of walls need to be massive - prefeably 2 foot thick. The basement of my 100+ years old summerhouse is made of splitted fieldstone. Those walls are approximately 2 foot thick. The ceiling of the basement is the shape of an arch and is also made of fieldstones. There is also no rebar in the walls or ceiling. What amazes me is the complete lack of visible cracks in the walls. I think the mortar they used back then is more elastic than a simple cement mortar. They used lime mortar which is not as strong but more elastic than cement mortar.

Nope. Those are cuts. Cuts are not cracks.

You're really reaching, aren't you. Special pleading fallacy.

I don't think you do

Iron that is not exposed to water will not rust. Rebar is properly laid concrete is not exposed and does not rust.

Traffic wear is not rust.

This rebar was exposed by poor pouring and traffic wear.

Cracks are not inevitable.

Xadoman wrote:

Nope. Those are cuts. Cuts are not cracks.

Those are cuts to control cracking. The cracks will simply go along the sawcuts. Simple as that. You do not see them because they are located inside the sawcut.

Xadoman wrote:

You're really reaching, aren't you. Special pleading fallacy.

Cracks can be really small. In micrometers. People wont see those with bare eyes. Do not you agree? Or is there something I am missing here?

Xadoman wrote:

I don't think you do

Tell me, you are the one who is going to wear a mask soon. Harvey, gfm and some others here already are.

Xadoman wrote:

Iron that is not exposed to water will not rust. Rebar is properly laid concrete is not exposed and does not rust.

Ever head about capillary action? Pretty basic physics. This is also why they use a capillary brake at the top of the foundation - to stop the wood from rotting or wall from wetting that is in contact with concrete which is in contact with soil full of water and dampness. This kind of damp proof layer is also very important when you want to build a basement and keep it not getting filled with water during high surface water periods. In this case you need to wrap the whole basement into the damp proof membrane. Easily said than done. I would not risk it myself because if you let a small hole into the membrane then the whole work is wasted money. A small hole in a rubber boot makes its ineffective. Simple rule of communicating vessels.

Xadoman wrote:

Traffic wear is not rust.

Traffic wear is only one component of overall wear and tear.

Xadoman wrote:

This rebar was exposed by poor pouring and traffic wear.

The main point of the video was to show an alternative method that is used to protect rebar.

Xadoman wrote:

Cracks are not inevitable.

Could you give me an example where and when was the concrete layed that has no cracks?

Xadoman wrote:Tell me, you are the one who is going to wear a mask soon. Harvey, gfm and some others here already are.

Xadoman wrote:

Nope. Those are cuts. Cuts are not cracks.

Those are cuts to control cracking. The cracks will simply go along the sawcuts. Simple as that. You do not see them because they are located inside the sawcut.

You're really reaching, aren't you. Special pleading fallacy.

Cracks can be really small. In micrometers. People wont see those with bare eyes. Do not you agree? Or is there something I am missing here?

I don't think you do

Tell me, you are the one who is going to wear a mask soon. Harvey, gfm and some others here already are.

Iron that is not exposed to water will not rust. Rebar is properly laid concrete is not exposed and does not rust.

Ever head about capillary action? Pretty basic physics. This is also why they use a capillary brake at the top of the foundation - to stop the wood from rotting or wall from wetting that is in contact with concrete which is in contact with soil full of water and dampness. This kind of damp proof layer is also very important when you want to build a basement and keep it not getting filled with water during high surface water periods. In this case you need to wrap the whole basement into the damp proof membrane. Easily said than done. I would not risk it myself because if you let a small hole into the membrane then the whole work is wasted money. A small hole in a rubber boot makes its ineffective. Simple rule of communicating vessels.

Traffic wear is not rust.

Traffic wear is only one component of overall wear and tear.

This rebar was exposed by poor pouring and traffic wear.

The main point of the video was to show an alternative method that is used to protect rebar.

Cracks are not inevitable.

Could you give me an example where and when was the concrete layed that has no cracks?

James___ wrote:

Xadoman wrote:

Nope. Those are cuts. Cuts are not cracks.

Those are cuts to control cracking. The cracks will simply go along the sawcuts. Simple as that. You do not see them because they are located inside the sawcut.

You're really reaching, aren't you. Special pleading fallacy.

Cracks can be really small. In micrometers. People wont see those with bare eyes. Do not you agree? Or is there something I am missing here?

I don't think you do

I wear a mask briefly, when I enter work, and get temperature scanned. I take it off, and shove it in my pocket, before I even reach my locker. The rest of my day at work, is entirely mask-free. I'm pretty sure the health department would give me, and most everyone working out in the warehouse an mask exemption. I know I wouldn't have a problem, my shirt is often soaked with sweat during the summer months, and so would a mask. Sort of like waterboarding the workers... Just too much physical activity, to restrict breathing. The only two businesses that require, and insist on masks, are Walmart, and Home Depot. Walmart is usually once a week. I haven't been stopped for walking around town, without a mask. Social distancing doesn't seem to be an issue either. Pretty sure the no-maskers out number the mask-slaves, in most public places. I'd of course respect the business owner, or a homeowner's wishes, far as mask mandates, but won't just wear on, just because all the cool democrats are wearing them. I see no benefit from wearing one. I'm not infected, so can't be spreading anything. I'm well enough protected, and have been for decades. Rare to catch a cold, haven't had the flu since college. I don't need a mask, anymore than I need training wheels on my bicycle. Don't wear a helmet or pads either... Lean on your crutch, if you feel you need it. I won't do the same, as I can walk just fine.

Tell me, you are the one who is going to wear a mask soon. Harvey, gfm and some others here already are.

Iron that is not exposed to water will not rust. Rebar is properly laid concrete is not exposed and does not rust.

Ever head about capillary action? Pretty basic physics. This is also why they use a capillary brake at the top of the foundation - to stop the wood from rotting or wall from wetting that is in contact with concrete which is in contact with soil full of water and dampness. This kind of damp proof layer is also very important when you want to build a basement and keep it not getting filled with water during high surface water periods. In this case you need to wrap the whole basement into the damp proof membrane. Easily said than done. I would not risk it myself because if you let a small hole into the membrane then the whole work is wasted money. A small hole in a rubber boot makes its ineffective. Simple rule of communicating vessels.

Traffic wear is not rust.

Traffic wear is only one component of overall wear and tear.

This rebar was exposed by poor pouring and traffic wear.

The main point of the video was to show an alternative method that is used to protect rebar.

Cracks are not inevitable.

Could you give me an example where and when was the concrete layed that has no cracks?

Usually concrete is sealed. While the surface is subject to wear and tear, the sealant gets into the cracks and crevices just below the surface. It's a filler of sorts. Kind of like using a passive layer on rebar, a little protection goes a long way.

p.s., I wear a mask and don't mind safe practices. They have been shown to work. And I'm not sure why it's such an issue. At the same time there is no global warming and not sure how Iowa got wiped out by a storm it's never had before. And only a 39% chance that where GasGuzzler lives was it hit.
Kentucky is just fine so why be concerned ? Just parroting gfm7175.

duncan61 wrote:
5 pages of making concrete and now face masks again.The warming crowd must be very quiet at the moment

Sure. My sidewalk. The foundation of my house (slab foundation). Not a single crack in any of them. The house was built 45 years ago. The sidewalk was laid then also.

Common iron rebar in both.

Others have also given you examples. RQAA.

Usually concrete is sealed. While the surface is subject to wear and tear, the sealant gets into the cracks and crevices just below the surface. It's a filler of sorts. Kind of like using a passive layer on rebar, a little protection goes a long way.

duncan61 wrote:
5 pages of making concrete and now face masks again.The warming crowd must be very quiet at the moment

James___ wrote:

Xadoman wrote:

Nope. Those are cuts. Cuts are not cracks.

Those are cuts to control cracking. The cracks will simply go along the sawcuts. Simple as that. You do not see them because they are located inside the sawcut.

You're really reaching, aren't you. Special pleading fallacy.

Cracks can be really small. In micrometers. People wont see those with bare eyes. Do not you agree? Or is there something I am missing here?

I don't think you do

Tell me, you are the one who is going to wear a mask soon. Harvey, gfm and some others here already are.

Iron that is not exposed to water will not rust. Rebar is properly laid concrete is not exposed and does not rust.

Ever head about capillary action? Pretty basic physics. This is also why they use a capillary brake at the top of the foundation - to stop the wood from rotting or wall from wetting that is in contact with concrete which is in contact with soil full of water and dampness. This kind of damp proof layer is also very important when you want to build a basement and keep it not getting filled with water during high surface water periods. In this case you need to wrap the whole basement into the damp proof membrane. Easily said than done. I would not risk it myself because if you let a small hole into the membrane then the whole work is wasted money. A small hole in a rubber boot makes its ineffective. Simple rule of communicating vessels.

Traffic wear is not rust.

Traffic wear is only one component of overall wear and tear.

This rebar was exposed by poor pouring and traffic wear.

The main point of the video was to show an alternative method that is used to protect rebar.

Cracks are not inevitable.

Could you give me an example where and when was the concrete layed that has no cracks?

Usually concrete is sealed. While the surface is subject to wear and tear, the sealant gets into the cracks and crevices just below the surface. It's a filler of sorts. Kind of like using a passive layer on rebar, a little protection goes a long way.

p.s., I wear a mask and don't mind safe practices. They have been shown to work. And I'm not sure why it's such an issue. At the same time there is no global warming and not sure how Iowa got wiped out by a storm it's never had before. And only a 39% chance that where GasGuzzler lives was it hit.
Kentucky is just fine so why be concerned ? Just parroting gfm7175.

Xadoman wrote:

Sure. My sidewalk. The foundation of my house (slab foundation). Not a single crack in any of them. The house was built 45 years ago. The sidewalk was laid then also.

Common iron rebar in both.

Others have also given you examples. RQAA.

There are shrinkage cracks at the bottom of the slab.

Xadoman wrote:
I am sure there are also hairline cracks at the top of the slab.

Xadoman wrote:
Those are also cracks not only the ones you could shove an entire hand into.

Xadoman wrote:
Also the reinforcement in your slab is not structural

Xadoman wrote:
- its job was to minimize shrinkage cracking and to keep the cracks from opening up more.

Xadoman wrote:
Most probably it is a thin reinforcement net, also suitable for building a fence for chickens.

Xadoman wrote:
Most of the time workers walk on it during the pour and it simply falls down to the bottom of the slab doing nothing there.

Xadoman wrote:
With suspended slab the reinforcement has to be structural.

Xadoman wrote:
Both will crack though.

Xadoman wrote:

Usually concrete is sealed. While the surface is subject to wear and tear, the sealant gets into the cracks and crevices just below the surface. It's a filler of sorts. Kind of like using a passive layer on rebar, a little protection goes a long way.

I have heard about those products that you can varnish onto the concrete. The concrete is quite porous and absorbs those and supposedly they give a much better protection for chlorides. The guy who poured my garage slab told me about those. He is a concrete guy and he said that surface becomes really smooth and shiny after the treatment and oil and other liquids are not going to stain the concrete anymore. He also said that he ordered it from US. I am probably going to use it on my garage floor which has a common rebar inside( 12mm rebar with 150mm spacing) the slab.

You cannot see my slab, moron.
You cannot see my slab, moron. There are no cracks.

Yes it is.

Nope. That's an improper installation. The concrete will fail. The installers can be sued if they do that.

Slab on grade is one of the most trouble prone of all concrete elements, so be careful.

Reinforcing
It is common to place reinforcing steel in the upper one-quarter of the slab thickness. This is
somewhat contrary to flexural mechanics. Maximum flexural moments occur at the bottom fibre of the slab. In addition, tractions produced by the base material on the bottom of the slab, tend to increase the bottom fibre tension and put the top fibres of the slab in compression. The reason for placing the steel in the top is to minimise cracking on the top surface which is subject to 'wear and tear'. Cracking of the top surface is not aesthetically pleasing because it is visible. Cracking of the underside is not so noticeable.
Reinforcing is often placed in a single layer near the top of the slab. It is common to place the
reinforcing to provide a concrete cover equal to the depth of the sawcut.
Cracks on the top become accentuated with time due to objects moving over the top surface.
Although some jurisdictions permit reinforcing steel to be placed at five times the slab thickness, a spacing of three times the slab thickness should be considered.
The effect of reinforcing in small amounts is somewhat nebulous and its main function is to hold the concrete sections together to help develop the aggregate interlock at the fractured surface. For improperly timed, sawcut joints, is also helps distribute cracking a little better and minimises crack widths.
It is common to provide 0.2% of the concrete area as reinforcing steel area. This proportion can be increased to 0.5% or 0.6% to largely 'eliminate' visible cracking. The cracks still occur, but they are much more frequent and have a greatly reduced crack width.

Control Joints and Sawcutting
Unreinforced, or minimally reinforced, slabs usually have control joints located at 35x to 40x the slab thickness, but not greater than 5m or so. This is recommended by the ACI SOG committee.
If the structure is unheated, then the sawcuts should be at a closer spacing.
It should be noted that the time for sawcutting is critical. This is more important for a thin slab. A thin slab reacts to changes in temperature, and humidity.
The sawcuts should be made with an "early entry" saw, or 'Soff-Cut' saw, that permits sawcutting within two to four hours of the completion of the floor finishing. Sawcut timing is critical. Without an early entry saw, sawcutting should commence within 6 to 8 hours after finishing. CSA A23 stipulatesthat sawcutting should commence as soon as possible. Concrete should have sufficient strength to prevent the aggregate from ravelling behind the saw blade. If too much time passes, sawcutting is superfluous and the location of the microcracking has determined where the cracks will form.
The depth of sawcut should be a minimum of one-quarter of the slab thickness.
The sawcutting pattern should correspond with any interior columns.
For irregular shapes, the sawcutting pattern can be shown on the construction documents.
In addition to sawcutting, construction joints should be located at approximately every twenty metres.
Projections or re-entrant corners in the slab that will restrain movement should be detailed so they are isolated.
After the initial shrinkage has occurred, sawcuts should be filled with a caulk material that adheres to the concrete sawcut face and provides support for the concrete adjacent to the sawcut. This can be a polyurethane material that has a hardness to prevent the ingress of particles. For heavier loadedslabs, the caulk hardness should be increased.

Xadoman wrote:

You cannot see my slab, moron.
You cannot see my slab, moron. There are no cracks.

I know your slab is cracked. Do not have to see it at all.

Xadoman wrote:
Also do not take it so bad - after all, every concrete cracks. It is perfectly normal.

Xadoman wrote:

Yes it is.

Did you pour it yourself? Most probably you do not know what kind of rebar is inside the concrete.

Xadoman wrote:

Nope. That's an improper installation. The concrete will fail. The installers can be sued if they do that.

It will not fail if it is a slab on grade.

Xadoman wrote:
Most probably it will outlast the slab that has simple iron in it because of the rust problem.

Xadoman wrote:
Also , I would like to know how thick is your slab and does it have one or two layers of reinforcement and how thick is the concrete cover?

Xadoman wrote:
Also a quote from eng-tips forum:

Slab on grade is one of the most trouble prone of all concrete elements, so be careful.

Xadoman wrote:
Also just some information from eng-tips forum about slab on grade:
...deleted Holy Quote...

Into the Night wrote:

Xadoman wrote:
Also just some information from eng-tips forum about slab on grade:
...deleted Holy Quote...

Irrelevance fallacy.

4 inches, other than the footing.

Xadoman wrote:

4 inches, other than the footing.

Clear, that is a typical slab on grade with one layer of reinforcement. Concrete cover is recommended to be 3 inches where the concrete is directly connected with soil. So the rebar is most probably somewhere in the middle or near the top. This kind of slab is not structural as are suspended slabs that require rebar to support their own weight and future loads. This slab lays on the compacted fill which holds the slab in place and gives it the load bearing capacity. The reinforcement could help to increase the load capacity but even without the reinforcement the slab could hold a truck. Anyway, either simple slab on grade or suspended slab, both will crack. Shrinkage cracks are inevitable. Your slab has those and millions of other slabs that have been poured all over the world have those cracks. Sorry about bursting your bubble but that is a real life.

Xadoman wrote:

4 inches, other than the footing.

Clear, that is a typical slab on grade with one layer of reinforcement. Concrete cover is recommended to be 3 inches where the concrete is directly connected with soil. So the rebar is most probably somewhere in the middle or near the top.

Xadoman wrote:
This kind of slab is not structural

Xadoman wrote:
as are suspended slabs that require rebar to support their own weight and future loads.

Xadoman wrote:
This slab lays on the compacted fill which holds the slab in place and gives it the load bearing capacity.

Xadoman wrote:
The reinforcement could help to increase the load capacity but even without the reinforcement the slab could hold a truck.

Xadoman wrote:
Anyway, either simple slab on grade or suspended slab, both will crack.

Xadoman wrote:
Shrinkage cracks are inevitable.

Xadoman wrote:
Your slab has those

Xadoman wrote:
and millions of other slabs that have been poured all over the world have those cracks.

Xadoman wrote:
Sorry about bursting your bubble but that is a real life.

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Most composting toilet systems rely on mesophilic composting. Longer retention time in the composting chamber also facilitates pathogen die-off.

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Composting toilets differ from pit latrines and arborloos, which use less controlled decomposition and may not protect groundwater from nutrient or pathogen contamination or provide optimal nutrient recycling.

Composting toilets can reduce or perhaps eliminate the need for a septic tank system to reduce environmental footprint (particularly when used in conjunction with an on-site greywater treatment system).

Waste-derived compost recycles fecal nutrients, but it can carry and spread pathogens if the process of reuse of waste is not done properly. Pathogen destruction rates in composting toilets are usually low, particularly helminth eggs, such as Ascaris eggs.[6] This carries the risk of spreading disease if a proper system management is not in place. Compost from human waste processed under only mesophilic conditions or taken directly from the compost chamber is not safe for food production.[9] High temperatures or long composting times are required to kill helminth eggs, the hardiest of all pathogens. Helminth infections are common in many developing countries.

Unlike pit latrines, composting toilets convert feces into a dry, odorless material, avoiding the issues surrounding liquid fecal sludge management (e.g. odor, insects and disposal). These toilets minimize the risk of water pollution through the safe containment of feces in above-ground vaults, which allows the toilets to be sited in locations where pit-based systems are not appropriate.

However, composting toilets face higher capital costs (although lifecycle costs might be lower) and greater complexity (for instance, adding covering materials and managing moisture content).

Unlike flush toilets, composting toilets do not dilute waste and create wastewater streams which must be treated before disposal. On the other hand, wastewater treatment plants can centralize waste management for an entire community, with potentially greater efficiency.

Numerous sparsely settled villages in rural areas in Finland are not connected to municipal water supply or sewer networks, requiring homeowners to operate their own systems. Individual private wells, i.e. shallow dug wells or boreholes in the bedrock, are often used for water supply, and many homeowners have opted for composting toilets. In addition, these toilets are common at holiday homes, often located near sensitive water bodies. For these reasons, many manufacturers of composting toilets are based in Finland, including Biolan, Ekolet, Kekkilä, Pikkuvihreä and Raita Environment.[34][35]

Estimates made by leading Finnish composting toilet manufacturers and the Global Dry Toilet Association of Finland provided the following 2014 figures for composting toilet use in Finland:

About 4% of single-family homes not connected to a public sewer network are equipped with a composting toilet.
Some 200,000 manufactured composting toilets are thought to serve holiday homes, matched by the number of other dry toilets. The simplest ones are sited in an outhouse.

Slow composting toilets have been installed by the Green Mountain Club in Vermont's woodlands. They employ multiple vaults (called cribs) and a movable building. When one of the vaults fills, the building is moved over an empty vault. The full vault is left untouched for as long as possible (up to three years) before it is emptied. The large surface area and exposure to air currents can cause the pile to dry out. To counteract this, signs instruct users to urinate in the toilet

In the middle, right where it's supposed to be.

Yes it is.

They both require rebar.

Define 'truck'.

No.
No.
No.
Your hallucinations and statements of clairvoyance are not real life.

Xadoman wrote:

In the middle, right where it's supposed to be.

Fine by me. Though it is not structural. It only helps to keep the cracked concrete together.

Xadoman wrote:
This slab would collapse if used as suspended slab. The suspended slab has to have a reinforcement at the bottom side( simple beam) or both at bottom and top( continuous beam).

Xadoman wrote:
The heavy reinforcement in suspended slabs also work as a great crack control but the reinforcement of course does not eliminate cracking , it only keeps the cracking to a minimum an does not allow the cracks to open up more.

Xadoman wrote:
The reinforcement you got in the middle does not help if the slab is rised a bit from one side by the frost heave or swelling clay.

Xadoman wrote:
Also, I would not call it a foundation.

Xadoman wrote:
4inch thick slab in not a foundation, it is a floor.

Xadoman wrote:
If you want a serious slab foundation then consider at least a foot thick slab with double mat reinforcment ( one at the bottom and the other on the top).

Xadoman wrote:

They both require rebar.

No. See the code ( ACI)

Xadoman wrote:

Define 'truck'.

Gazguzzler already did.

Xadoman wrote:
Answered many times. Quotes from eng-tips forum ( real life bridge and skyscrapers designers and builders) also included.

HarveyH55 wrote:
This outhouse, isn't a skyscraper (right?). You are trying to apply thing used for massive scale projects, to something very tiny, in compassion. Concrete isn't that frail for small structures. I don't know the scale of this outhouse project, but certainly, it's much smaller than a house.

To have the huge impact on the lake ecosystem, you'd need to be dumping a much larger volume of sewage into it, regularly. The water should be flowing in and out of the lake, carrying of contaminants constantly. Sewage, isn't the only factor that causes algae blooms, or even over growth of vegetation. I really don't see how one 'high-tech' outhouse is going to make any large scale impact on the lake. It's highly unlike you are going to convince/compel your neighbors to rip out septic systems, to install $6,000 outhouses, specially those that are there the whole year, not just a few weeks, or a month or two.

This outhouse, isn't a skyscraper (right?). You are trying to apply thing used for massive scale projects, to something very tiny, in compassion. Concrete isn't that frail for small structures. I don't know the scale of this outhouse project, but certainly, it's much smaller than a house.

Xadoman wrote:

This outhouse, isn't a skyscraper (right?). You are trying to apply thing used for massive scale projects, to something very tiny, in compassion. Concrete isn't that frail for small structures. I don't know the scale of this outhouse project, but certainly, it's much smaller than a house.

Rebar rusting is a big problem with both small scale and large scale projects.

Xadoman wrote:
The physics and chemistry of how the rebar rusts in both structures are basically the same.

Xadoman wrote:
Eng-tips forum is a very good place to gather information about construction.

Xadoman wrote:
Also, do not you agree, that before going large scale it is a good idea to practise on small scale projects?

Don't go large scale.