How Do I Reduce (Eliminate?) the Conductivity of Road Salt

• Wash it away with a hose.
• Sweep it away with a broom.
• Etc.

• Install it on a gradient so that what falls on it runs off.

Thank you -interesting idea - others have previously suggested if the design was more like a speed bump presumably the salt would not bridge - up to now we have focused on being flush with the roadway to assist with snow clearing (plows)

What about a 6" to 1' (15cm to 30cm) rubber wall added to one of the mats?

A physical gap (e.g. a drainage channel) between the two pads. As long as it didn't fill (with water, salt or debris) it should considerably reduce, if not eliminate, the leakage.

It does rather sound as though the design for this thing is somewhat lacking.

innovation can be a bruising sport at times but "challenges" lead to improvements!

Maybe try posting this intriguing question in the Chemical & Material Science Forum, someone there might have an idea for an electrically activated ion exchange process with some special catalytic material deposited between the electrodes.

Power source for the mat during storms...

Probably too costly to wash the mat surface, using a special add-on kit designed for the few? areas that will be salted... A sensor that detects continuous current draw could activate a small diaphragm pump (aquarium) slowly diluting the insulator area with some distilled water (vegetable oil?) (ethyl alcohol?) kept warm by your thermostatically controlled reservoir, until current draw returns to normal...

Assuring flow to each of multiple micro pores in the surface where some might plug is an exercise in hydraulic engineering, and some good old fashioned trial & error, multiple pumps...

But the OP is probably not wanting to actually kill the wildlife that might cross astride both pads. Besides, how is that supposed to work if the beast decides to only stand on one pad all the way through?

I would also post a sign warning the road salting crew that certain male appendages may fall off after the salt has been collected and selectively re-sprayed at high velocity!

I would try a heater to keep the pad above the freezing level....Insulating the underneath of the slab might help....Drain channels....motion activated sound and/or lights to scare the deer....pressure sensitive pulsed higher voltage electroshock...

Maybe some kind of superhydrophobic coating might help. If there is not too much liquid (salt + water) present, it will bead up and not allow a complete circuit between the electrodes. Use this in addition to what others have suggested by making the surface not flat so the liquid will drain away.

http://www.aculon.com/hydrophobic-coatings.php

You do know that road salt is not the only contaminate that these mats will have to deal with. That they will need to be cleaned to keep contaminates from shorting them out. So the road crews need to maintain them. I hope in you sales pitch you let them know.

Were salt to have little to no conductivity it wouldn't dissolve, and then not dissolving wouldn't lower the freezing point of water.

Aircraft operators do not use salt to remove ice from aircraft; they use something else.

Sugar has no conductivity but dissolves easily in water, as do many non-electrolytes - solid and liquid. Example: isopropanol in windscreen washers.

Yeah, use glycol. EG will take care of deer on the roadway, but they will all pile up on the pads after they enjoy the sweet treat.

Glycol fails the selection test. Putting glycol onto a road surface will yield a growth of biofilm, which will affect in a negative way:

- the grip of vehicles passing over it

- the tendency of fauna to feed on it

- the health of the fauna that feeds on it, and therefore

- there is a risk of the roadway becoming impassable

therefore glycol is a "silly idea" or a "ridiculous suggestion" in common parlance. GA

Why thank you P.W.!

Sugar fails the selection test, as it doesn't lower the freezing temperature. Putting sugar solution onto a road surface will yield a growth of biofilm, which will affect in a negative way:

- the grip of vehicles passing over it

- the tendency of fauna to feed on it

- the health of the fauna that feeds on it, and therefore

- there is a risk of the roadway becoming impassable

therefore sugar solution is a "silly idea" or a "ridiculous suggestion" in common parlance.

You wrote: "Were salt to have little to no conductivity it wouldn't dissolve."

I was merely pointing out that your statement is simply incorrect, NOT suggesting that sugar could be used instead. So it was not a "silly idea," merely a statement of fact. Kapeesh?

I think they usually use Propylene Glycol to deice aircraft (PGI), also used as automobile radiator antifreeze. Almost anything that will dissolve in water lowers the freezing point, a trait common for most substances due to the presence of solute molecules interfering with the freezing of the solvent.

https://en.wikipedia.org/wiki/Freezing-point_depression

I suspect the OP probably doesn't have any control over the deicing agent used.

potassium acetate is one antifreeze for aircraft, I think it's highly conductive

A non-ionic desalting compound, like Urea prills(little rounded shapes), should help. As would a separation between the two polarities (insert un-connected pieces into the mosaic)

Like said above, elevate the section and slope it to drain it and add a heating circuit that will help dry it faster. If you could include a sound and light system that triggers as they approach they will learn to recognize the hazard and avoid it without triggering it.

Drew K

One step further and it becomes a novel animal discotheque.

Another thing you can try is a high resistance inserted in the line that feeds each plate. This would require a mosaic of plates wired with the resistor in each positive plate, The negatives can be common to ground. Between a + plate and ground is the high voltage at low current to deter the wild life. A short between any plate and ground would not disable the other plates as the resistor would reduce current flow from the upstream high voltage. The mosaic can be like a checkerboard, or more simply, stripes.

You will have to wash them off with pure water (RO water, rain water, melted snow, or condensate.)

Even then I have my doubts as to whether you will be able to restore the pads to original condition based on porosity issue, presence of reinforcements with corrosion taking place, etc.

Another simple grid pattern that might work: cross-hairs. ON the deer, silly!

How about making the mats pressure sensing such that voltage across the mats is only applied when it senses enough weight to suggest something is standing on it.

Perhaps no sensing need nlbe involved, just an insulator that can be squished out or the way between two conductive surfaces.

Use a cattle grid, like they do in Australia. No maintenance. Lasts for 100 years, costs very little and no cattle get through.

Yep. Commonplace in other countries too. GA

A. Get a cattle grid like they got in Australia.

B. Put a homeless person to work who doesn't mind standing in the freezing cold sweeping and washing down the grid surface 24/7.

C) with insulating rubber boots, or you will get an OSHA rip.

From what's been written so far, I suspect you will have to give up on changing the environment in winter to accommodate the needs of your product. This argues for changing your product in ways that accommodate the environment - a very more useful expedient, though more difficult.

There are two things that must be accommodated:

1) detecting the presence of an animal

2) administering sufficient shock (or other stimulus) to deter it from crossing your barrier

If you wish to use the existing system to detect the presence of an animal, it will have to detect the much smaller change in voltage its presence will produce while the conductive salt solution is present. I suspect that this may be an obstacle that cannot be overcome.

An optical method might work; perhaps LED/photo-transistor pairs embedded in the road surface, but this will require communication with the controller, a rather large change to what started out as a simple device. A similar disadvantage accrues to setting up a gate of light beams passing from one side of the road to the other over the pads, though one needing a simpler interface.

Neither of these expedients deals with the problem of administering enough shock to move the animals back off the road; the icemelt is in parallel with your shock pads, and administering a shock will require higher voltage driving current through them to be felt - a possibly lethal current when dry. Safety considerations may rule this out as well.

A back-up deterrent might be employed, perhaps ultrasonic emitters and pulsed laser diodes strong enough to scare the animals back where they came. Again, this involves communication with the controller and a whole second set of deterrent devices erected nearby.

I spent some years near Killeen and also near Fort Worth, and winter ice coatings would seem to me as much a problem for your system as snow; how have you dealt with that?

Normally high voltage systems like this are sourced from high impedance sources and can not drive enough current to kill or injure an animal or person - but they are an unpleasant sensation and the animal draws back. My earlier suggestion to insert the current limiting resistor into the individual wire to a number of pads, interspersed with ground potential pads so that the animal will sense the potential and a short to ground by salt will only interfere with the current from that pad.

Of course, drifts of snow may well short out all currents, which is why salt is added.

The other suggestion is the use of a non-ionic ice melter, like urea, is valid. Ethylene Glycol can not be used because it runs away and is also toxic to animals. Propylene Glycol can also be used, as it is not toxic, but it also runs away.

Of course, coaxing the road crews to turn off the salter at your drive makes me feel you might build the pads a few feet onto your property and away from the road

I suspect that the salt will affect all of the pads at once. Once the salt has been washed away, there is no reason for the cleaning chemical to remain. Usually salting is a discrete event, not continuous application, (also not particularly good for concrete, but in small doses...)

It all depends on the continuity of the liquid phase, which will vary, and some pads will ne shorted and some not, as time progresses the pads might dry - it all depends on the amount of snow/ice/rain in the area. Rain in summer will short, but drain and dry off, so it will be erratic

Wouldn't that defeat the object?

No. One would use a side panel fence up to the pads. He had it right.

As for animals being scared with flashing lights and beeping sounds,,

I remember a time when Crows wanted to crack open a nut, they would drop them onto a road surface from a great height and they would be scared and fly away when a passing car or truck drove on that same road.

Then, the Crows evolved,,

Now they set the nut onto the road surface, wait along the curb for a passing vehicle to crack open the nut, then walk onto the highway to collect their reward.

'...Then, the Crows evolved...'

.

'Adapted', 'learned', or even 'upped their game' would be better.

When used as an intransitive verb (note there is no object) 'evolve' means to undergo evolutionary change.

As the change was unlikely to require multiple generations to occur, nor was any selective pressure influencing genetics likely to play a role, evolutionary change is unlikely to be a contributor to this behavior change.

.

As an interesting note; the behavior has become even more sophisticated with crows now using crosswalks and waiting for the appropriate 'walk' signal to time retrieval of the booty.

I was in a hurry, had to go to work, evolve was the first word that came to mind. I didn't know my English teacher was going to grade me on my grammar :)

Grammar? Was there a problem with your grammar?

Semantics is what I was discussing.

It is like Deja Vu all over again!

Is there no context of the word evolve that does not involve Darwin, just wondering?

verb (used with object), evolved, evolving. 1. to develop gradually: to evolve a scheme. 2. to give off or emit, as odors or vapors. verb (used without object), evolved, evolving. 3. to come forth gradually into being; develop; undergo evolution : The whole idea evolved from a casual remark. 4. to gradually change one's opinions or beliefs: candidates who are still evolving on the issue; an evolved feminist mom. 5. Biology. to develop by a process of evolution to a different adaptive state or condition: The human species evolved from an ancestor that was probably arboreal.

Sure there are non-Darwinian uses of 'evolve'; these are transitive verbs. Proper intransitive use is Darwinian.

I was sad when my grammar passed. Being a product of the times, unfortunately she was somewhat anti-semantic.

I think that is how it must be built, however the salt solution bridges the insulation between the pads, the whole assembly is flat to minimize impact to other operations, like plowing, cleanliness & foot traffic, for instance...

The leakage calculation has three factors, resistivity, crossectional area and voltage. The vertical edge of a nonconductive tray substantially reduces the cross section and thus reduces the leakage current. To work though, the edge of the insulator needs to be flush with the concrete surface or very slightly raised.

Can you give us an idea of the dimensions of the two pads, and space between them?

Sorry - thought I had replied earlier. Each section (pad) is approximately 24" wide. It is separated by approximately 2" by composite lumber which serves as the insulator

How do you actually ensure that the exotic animal in question will stand astride the two panels?

I think you should resort to a better insulator, or maybe the road salt is in fact bridging over the top of the lumber as a wet electrolyte slush.

Sounds similar to a mouse zapper that was described to me by an English fellow in a machinists discussion forum. At each doorway in his shop he runs two strips of copper tape separated by about 1-1/2" across the door threshold. The strips are connected to 220VAC and his mouse problem is nonexistent.

Only caution is that you don't go barefoot in the machine shop.

As far as animals bridging the concrete panels, statistics works pretty well over time.

we have a series of negative / positive sections - each 24" wide. So, typical stride width will result at least two legs on alternating charged sections.

There is no question that the salt is bridging over the composite lumber - that, sadly, is the problem.

The challenge is how to stop the bridging of the road salt. Ideas?

Have you considered using air as an inter-plate insulator? One way you could do this is to mount each section on top of its own insulated standoffs which in turn mount at the base of an excavated channel such that the tops of the plates are flush with the roadbed (think of a table with four or more short, stout legs). The insulators (porcelain is a good choice) would have to bear the weight of any traffic of course but being effectively shielded from contamination they should provide ample insulation from the ground and from the other plates. The air gap could be quite narrow actually, a half an inch or so. As with the channel under regular cattle guards, there is the risk of the channel filling with water, and so some sort of drainage would be advised. Also some way of removing the plates as necessary (or provide a side access) to remove debris that could build up underneath the plates, shorting them out.

Any solid insulator between the plates, no matter what is made of, and you will have a conductive surface once it is contaminated with road salt. You also run the risk of conductive water/slush pooling on the surface, shorting out the plates; slush especially. There needs to be somewhere for it to go; an air gap is one good way.

OK, can you replace the top of the lumber with a plastic and rubber extrusion:-

It's important that the rubber wall extends slightly higher than the walls of the trough/concrete.

You will probably need to figure out how to drain the trough at the ends, and, it might need cleaning out very occasionally.

What is stopping large wildlife from simply jumping over the mat? What kind of 'large wildlife'? Four feet plus the spacer distance is easily cleared by deer, no problem. Whitetail deer for example can jump as high as eight feet and as far as 30 feet horizontally. Once they realize they can't walk across it, they'll just jump over it like they would a deep stream or barbed-wire fence. It depends on how badly they want whatever is on the other side - or how fast something behind them is chasing them. What if the animals are at a dead run when they step on it? They might feel a shock but that just might spur them on to run even faster, right across your mat; their momentum alone would carry them over a 4+ foot-wide mat. I'm not meaning to rain on your parade, but maybe a mat isn't the solution - electrified or otherwise.

According to the OP the product does work under normal circumstances: just not, when there's salty water around.

I realize that, but then the OP didn't say what sort of wildlife it was tested with and under what circumstances. Living here in central Texas we have a big problem with deer and I can tell you they're not phased one bit by electric fencing nor cattle guards. They'll just jump right over it like it wasn't there.

I can see this mat working with slow-moving animals like cattle, for example, but not with deer and other faster, more agile animals; and if this product is available for sale generally, people are going to buy it to keep out deer and they're going to be very unhappy with the results, I guarantee it. This will not keep deer out, especially startled or running deer, and especially with the mat being only four feet wide.

"...Living here in central Texas we have a big problem with deer..."

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I realize Texans believe 'everything in Texas is big', but I have seen the deer in central Texas, and they are decidedly not big. Perhaps they would qualify as big if classified differently....

'big scrub deer'. That works.

The white tailed deer population, granted, is not as large as in other States, such as Michigan, or Maine. The mule deer population here in Texas is a good fair sized game animal, worthy of a hunt, with good meat. The mules, not so much, although they are also quite large.

I think OP is talking about limiting the migration of large Armadillos. An electric mat might stop one.

Why not just wait for global warming to eliminate the problem....?