# Does Sand + Clay = Concrete?



## Ware

Would you look at that. :bandit:















@wardconnor


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## social port

Thanks for posting this. I'm going to be looking into sand sources in the future.


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## Ware

social port said:


> Thanks for posting this. I'm going to be looking into sand sources in the future.


Don't take my word for it - I just wanted to start the conversation. :mrgreen:


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## SGrabs33

@wardconnor Is the new MythBuster! #wouldyoulookatthat


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## wardconnor

Exactly folks. Who the crap was it that started the retarded rumor that clay plus sand equals concrete? This is evidence that it is NOT correct.

That concrete rumor is a real pisser offer for sure.


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## Colonel K0rn

LOL, Thread of the month. #wouldyoulookatthat @SGrabs33 LOL


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## Mightyquinn

wardconnor said:


> Exactly folks. Who the crap was it that started the retarded rumor that clay plus sand equals concrete? This is evidence that it is NOT correct.
> 
> That concrete rumor is a real pisser offer for sure.


I think there was some wizardry at play in that rumor


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## osuturfman

Mightyquinn said:


> wardconnor said:
> 
> 
> 
> Exactly folks. Who the crap was it that started the retarded rumor that clay plus sand equals concrete? This is evidence that it is NOT correct.
> 
> That concrete rumor is a real pisser offer for sure.
> 
> 
> 
> I think there was some wizardry at play in that rumor
Click to expand...

I see what you did there.


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## Cory

wardconnor said:


> Exactly folks. Who the crap was it that started the retarded rumor that clay plus sand equals concrete? This is evidence that it is NOT correct.
> 
> That concrete rumor is a real pisser offer for sure.


Your soil can become concrete and contains chemicals known to the State of California to cause cancer http://www.patwelsh.com/soils/never-add-clay-to-sand-or-sand-to-clay/


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## Greendoc

wardconnor said:


> Exactly folks. Who the crap was it that started the retarded rumor that clay plus sand equals concrete? This is evidence that it is NOT correct.
> 
> That concrete rumor is a real pisser offer for sure.


Some agronomists with craniorectal inversion that wanted to ensure home lawns would be crappy and hard to maintain vs their perfect greens, fairways, and sports fields.


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## Spammage

Greendoc said:


> wardconnor said:
> 
> 
> 
> Exactly folks. Who the crap was it that started the retarded rumor that clay plus sand equals concrete? This is evidence that it is NOT correct.
> 
> That concrete rumor is a real pisser offer for sure.
> 
> 
> 
> Some agronomists with craniorectal inversion that wanted to ensure home lawns would be crappy and hard to maintain vs their perfect greens, fairways, and sports fields.
Click to expand...

While you may be right, most of what I've read (and I try to read all I can since I have calcareous clay) speaks more about amendment with sand - ie, tilling sand into the clay. Your sand capping, to me, doesn't meet that definition. I have been worried about even capping mine, but I have a few test areas working for a couple of years now that seem to be great. Even digging in those areas is easier than the rest of the yard, much like Connor's video.


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## wardconnor

OK folks.... I will do a core aerate with a Toro procore aerator. After the aeration, I will collect the cores and topdress immediately after with sand and drag the sand into the holes. This will and should amend the clay with sand as was mentioned above. We shall then see if the clay turns to concrete.

This will happen likely in the fall on my channel. I had it scheduled for 2 days ago but it was a no go when my hunny shut me down when I told her that it was going to cost some coin.


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## wardconnor

Ware said:


> Don't take my word for it - I just wanted to start the conversation. :mrgreen:


Mr Ware is stirring the pot.


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## Colonel K0rn

wardconnor said:


> OK folks.... I will do a core aerate with a Toro procore aerator. After the aeration, I will collect the cores and topdress immediately after with sand and drag the sand into the holes. This will and should amend the clay with sand as was mentioned above. We shall then see if the clay turns to concrete.
> 
> This will happen likely in the fall on my channel. I had it scheduled for 2 days ago but it was a no go when my hunny shut me down when I told her that it was going to cost some coin.


The Repair Man called in a special favor. 🤔


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## Delmarva Keith

As far as mixing it in making a difference, I just read a newspaper article about baseball diamond clay that explained that most of major league fields all use the same clay out of PA and it's too hard by itself. They mix in local sand (!) to soften the clay.

Here's a more "scholarly" article that prescribes sand (!) among the options to soften clay 
http://archive.lib.msu.edu/tic/wetrt/article/2002may60.pdf

I guess if sand did harden up clay like concrete, they wouldn't use sand to soften it (just a guess  ).

I've been adding sand in my own yard over the past couple of years to deal with some low areas that tend to stay wet during rainy periods of the seasons (like this past week - about 5" of rain over a few days) and it is definitely working. My theory is that the sand above the soil allows the crowns and enough of the roots to stay out of the water to obtain oxygen to avoid drowning. There's generally plenty of water under the sand in the soil year round to prevent overdrying. The lawn overall is much more walkable (no sinking in muck anymore when it's saturated) and the turf is doing well even in the wettest areas for the first time. I'm also keeping an eye on salinity due to the poor underlying drainage, but so far so good.


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## dfw_pilot

As if bermuda couldn't grow in concrete hard clay anyway, haha.


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## Ridgerunner

dfw_pilot said:


> As if bermuda couldn't grow in concrete hard clay anyway, haha.


What does bermuda have to do with growing grass? :rofl:


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## viva_oldtrafford

Ware said:


> social port said:
> 
> 
> 
> Thanks for posting this. I'm going to be looking into sand sources in the future.
> 
> 
> 
> Don't take my word for it - I just wanted to start the conversation. :mrgreen:
Click to expand...

I'll just leave these here.

https://s3.wp.wsu.edu/uploads/sites/403/2015/03/soil-amendments-2.pdf

https://durham.ces.ncsu.edu/files/library/32/UNH%203.PDF

https://www2.gov.bc.ca/assets/gov/farming-natural-resources-and-industry/agriculture-and-seafood/agricultural-land-and-environment/soil-nutrients/610000-3_managing_clay_soils_for_backyard_gardens.pdf

http://msue.anr.msu.edu/news/what_to_do_about_compacted_soil

http://extension.colostate.edu/docs/pubs/garden/07235.pdf

Seems we've stumbled upon settled science. Conversation ended? If not, can someone explain how the physical properties of S and C allow them to not create a brick-like texture?

I think it's worth noting that, despite what some people may think, their soil would need to contain no less than 40% clay, while simultaneously having higher levels of both sand and silt (or clay + very high levels of sand alone / clay + low-high levels of silt alone)in order to be classified as strictly clay.


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## Delmarva Keith

viva_oldtrafford said:


> ... Seems we've stumbled upon settled science. Conversation ended? If not, can someone explain how the physical properties of S and C allow them to not create a brick-like texture?
> 
> I think it's worth noting that, despite what some people may think, their soil would need to contain no less than 40% clay, while simultaneously having higher levels of both sand and silt (or clay + very high levels of sand alone / clay + low-high levels of silt alone)in order to be classified as strictly clay.


I think this might be a key sentence from one of the papers: "However, combined with organic amendments, some sand will help open up the compacting characteristics of clay soil." First off, as you note, what we all call "clay" likely isn't actually clay. Maybe more significantly, it would be just about impossible, as a practical matter, to exclude organic matter during the process of aerating and sand topdressing. It's possible and even likely that over the course of time and many applications, the process results in a "clay" / sand / organic matter mix that is beneficial to root penetration and drainage, and is not a brick.


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## viva_oldtrafford

Delmarva Keith said:


> viva_oldtrafford said:
> 
> 
> 
> ... Seems we've stumbled upon settled science. Conversation ended? If not, can someone explain how the physical properties of S and C allow them to not create a brick-like texture?
> 
> I think it's worth noting that, despite what some people may think, their soil would need to contain no less than 40% clay, while simultaneously having higher levels of both sand and silt (or clay + very high levels of sand alone / clay + low-high levels of silt alone)in order to be classified as strictly clay.
> 
> 
> 
> I think this might be a key sentence from one of the papers: "However, combined with organic amendments, some sand will help open up the compacting characteristics of clay soil." First off, as you note, what we all call "clay" likely isn't actually clay. Maybe more significantly, it would be just about impossible, as a practical matter, to exclude organic matter during the process of aerating and sand topdressing. It's possible and even likely that over the course of time and many applications, the process results in a "clay" / sand / organic matter mix that is beneficial to root penetration and drainage, and is not a brick.
Click to expand...

When we aerify greens, we use a 100% sand - there's almost no point in aerifying, only to go back with material that contains OM. With that said, you're probably right, getting a 100% sand mix for the homeowner might be a little more difficult (though not impossible). I wonder if any of these guys that do leveling projects get a particle size breakdown when the load is dropped in their driveway.

They key sentence leaves a lot to the imagination. There are 5 types of sand, and I feel that such a caveat would come with an explanation - ie: VFS @ 90% with 10% OM can help aggregate clay soil.


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## Delmarva Keith

viva_oldtrafford said:


> Delmarva Keith said:
> 
> 
> 
> 
> 
> viva_oldtrafford said:
> 
> 
> 
> ... Seems we've stumbled upon settled science. Conversation ended? If not, can someone explain how the physical properties of S and C allow them to not create a brick-like texture?
> 
> I think it's worth noting that, despite what some people may think, their soil would need to contain no less than 40% clay, while simultaneously having higher levels of both sand and silt (or clay + very high levels of sand alone / clay + low-high levels of silt alone)in order to be classified as strictly clay.
> 
> 
> 
> I think this might be a key sentence from one of the papers: "However, combined with organic amendments, some sand will help open up the compacting characteristics of clay soil." First off, as you note, what we all call "clay" likely isn't actually clay. Maybe more significantly, it would be just about impossible, as a practical matter, to exclude organic matter during the process of aerating and sand topdressing. It's possible and even likely that over the course of time and many applications, the process results in a "clay" / sand / organic matter mix that is beneficial to root penetration and drainage, and is not a brick.
> 
> Click to expand...
> 
> When we aerify greens, we use a 100% sand - there's almost no point in aerifying, only to go back with material that contains OM. With that said, you're probably right, getting a 100% sand mix for the homeowner might be a little more difficult (though not impossible). I wonder if any of these guys that do leveling projects get a particle size breakdown when the load is dropped in their driveway.
> 
> They key sentence leaves a lot to the imagination. There are 5 types of sand, and I feel that such a caveat would come with an explanation - ie: VFS @ 90% with 10% OM can help aggregate clay soil.
Click to expand...

Just to clarify, I'm not saying the delivered sand contains OM; what I'm getting at is that I'm speculating that the process used to sand top-dress by most of us doing it on lawns tends to incorporate by default some of the OM naturally occuring on site (like thatch, grass and clippings, aeration cores, and root cycling that's just already there). This might partially explain the divide between lab type results in the papers cited and what we are actually seeing in the ground. It doesn't turn into a brick so that might explain why. :thumbup:

I use mason sand - it's a good mix of particle sizes, has an ASTM "envelope" for reasonably consistent characteristics, load to load, and it's readily available at reasonable prices. I've been known to (don't tell anyone  ) mix in peat moss 1:1 V/V (like they used to do for greens eons ago) for particular deep trouble spots. That also works very well in practice.

I know you golf guys are a lot more particular about the sand, and take pains to exclude added OM from the root zone, but the mason sand works well enough on a lawn and the process used as well as the passage of time tend to naturally incorporate OM (along with the clay particles filtering in) which is apparently beneficial on a lawn.


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## Greendoc

Big difference between sand capping/topdressing and doing what I have seen well meaning people do which is till in small amounts of sand. @viva_oldtrafford and the universities are right. Do not till in small amounts of sand. The sand has to be the majority component in the soil or a brick will be made. My soils are typically almost 0 sand mostly clay and up to 10% OM. In order for tilling in sand to work, enough sand must be added that clay/OM percentage drops to 30% or less in the mix.


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## Ware

wardconnor said:


> Ware said:
> 
> 
> 
> Don't take my word for it - I just wanted to start the conversation. :mrgreen:
> 
> 
> 
> Mr Ware is stirring the pot.
Click to expand...

Would I do that? :lol:

I was practicing my click bait, but I'm going to change the title to something a little less abrasive. :bandit:


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## Delmarva Keith

Greendoc said:


> Big difference between sand capping/topdressing and doing what I have seen well meaning people do which is till in small amounts of sand. @viva_oldtrafford and the universities are right. Do not till in small amounts of sand. The sand has to be the majority component in the soil or a brick will be made. My soils are typically almost 0 sand mostly clay and up to 10% OM. In order for tilling in sand to work, enough sand must be added that clay/OM percentage drops to 30% or less in the mix.


Tilling in anything will never be a problem for me. Too much labor. I'm growing landscapes, not corn. :lol:

But seriously, important distinction - good to know. :thumbup:


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## wardconnor

wardconnor said:


> OK folks.... I will do a core aerate with a Toro procore aerator. After the aeration, I will collect the cores and topdress immediately after with sand and drag the sand into the holes. This will and should amend the clay with sand as was mentioned above. We shall then see if the clay turns to concrete.
> 
> This will happen likely in the fall on my channel. I had it scheduled for 2 days ago but it was a no go when my hunny shut me down when I told her that it was going to cost some coin.


ok folks. I did the core aeration and the sand on top of the core aeration. This happend within the last 2 weeks.

I have not seen any concrete appear in my lawn or soil.

I would more so say that cement would be what would cause the concrete to appear. I did not add any cement.


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## Ridgerunner

@wardconnor You've got high pH soil don't you? Well that's limestone soil! Sand, stones (I've seen you pick a stone out btw) and limestone and global warming. It's just a matter of time. You're gonna be sorry when daytime temps get hot enough to create cement and your whole yard turns into concrete at the first rain!!!


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## wardconnor

Well I guess we will see. I do not know how long I will be there maybe long enough to see the earth burn up who knows.

If it turns into concrete then I guess I will have to do something about it.

Yes I have high PH. I live in a lake bed.


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## Ridgerunner

@wardconnor 
Wait. What? The earth would burn up at 1600F? Oh. :shock: 







> If it turns into concrete then I guess I will have to do something about it.


Air8?


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## PA Lawn Guy

viva_oldtrafford said:


> Delmarva Keith said:
> 
> 
> 
> 
> 
> viva_oldtrafford said:
> 
> 
> 
> ... Seems we've stumbled upon settled science. Conversation ended? If not, can someone explain how the physical properties of S and C allow them to not create a brick-like texture?
> 
> I think it's worth noting that, despite what some people may think, their soil would need to contain no less than 40% clay, while simultaneously having higher levels of both sand and silt (or clay + very high levels of sand alone / clay + low-high levels of silt alone)in order to be classified as strictly clay.
> 
> 
> 
> I think this might be a key sentence from one of the papers: "However, combined with organic amendments, some sand will help open up the compacting characteristics of clay soil." First off, as you note, what we all call "clay" likely isn't actually clay. Maybe more significantly, it would be just about impossible, as a practical matter, to exclude organic matter during the process of aerating and sand topdressing. It's possible and even likely that over the course of time and many applications, the process results in a "clay" / sand / organic matter mix that is beneficial to root penetration and drainage, and is not a brick.
> 
> Click to expand...
> 
> When we aerify greens, we use a 100% sand - there's almost no point in aerifying, only to go back with material that contains OM. With that said, you're probably right, getting a 100% sand mix for the homeowner might be a little more difficult (though not impossible). I wonder if any of these guys that do leveling projects get a particle size breakdown when the load is dropped in their driveway.
> 
> They key sentence leaves a lot to the imagination. There are 5 types of sand, and I feel that such a caveat would come with an explanation - ie: VFS @ 90% with 10% OM can help aggregate clay soil.
Click to expand...

You seem knowledgeable, but unfortunately I don't understand what your last sentence is implying - is a finer sand or coarser sand preferred for topdressing/leveling a lawn?


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## viva_oldtrafford

PA Lawn Guy said:


> viva_oldtrafford said:
> 
> 
> 
> 
> 
> Delmarva Keith said:
> 
> 
> 
> I think this might be a key sentence from one of the papers: "However, combined with organic amendments, some sand will help open up the compacting characteristics of clay soil." First off, as you note, what we all call "clay" likely isn't actually clay. Maybe more significantly, it would be just about impossible, as a practical matter, to exclude organic matter during the process of aerating and sand topdressing. It's possible and even likely that over the course of time and many applications, the process results in a "clay" / sand / organic matter mix that is beneficial to root penetration and drainage, and is not a brick.
> 
> 
> 
> When we aerify greens, we use a 100% sand - there's almost no point in aerifying, only to go back with material that contains OM. With that said, you're probably right, getting a 100% sand mix for the homeowner might be a little more difficult (though not impossible). I wonder if any of these guys that do leveling projects get a particle size breakdown when the load is dropped in their driveway.
> 
> They key sentence leaves a lot to the imagination. There are 5 types of sand, and I feel that such a caveat would come with an explanation - ie: VFS @ 90% with 10% OM can help aggregate clay soil.
> 
> Click to expand...
> 
> You seem knowledgeable, but unfortunately I don't understand what your last sentence is implying - is a finer sand or coarser sand preferred for topdressing/leveling a lawn?
Click to expand...

We'd like it to match (as best as possible) the material that we're going to be topdressing over - uniformity is the name of the game in soil + turf related issues. For example, when we build a green, knowing our turf type dictates what size sand we really focus on. There are 5 types of sand - Very Coarse / Coarse / Medium / Fine / Very Fine (essentially silt) - so if we know that we'll be using an ultradwarf bermuda (say, tifeagle), we know that we can push for a finer mix vs a mix that we would use for a simple dwarf variety. That's because ultradwarfs are much more denser than the dwarf varieties; therefore, we need a mix that will work into the canopy and not get mowed up immediately following the topdressing - so if we plan to topdress with a mix that is on the finer side (talking maybe a 10% increase in one size of sand) we will build the green out of a sand that is 10% finer in one category.

At the end of the day, I would just try to avoid a sand that has a lot of fine and very fine sand in the mix. We like our mixes to have at least 60% in the coarse - medium range. All of this is golf related, and probably a bit overboard for a homeowner, but if it were me, I'd try and do what we do and focus on that C and M range and stay away from the F and certainly the VFS.


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## Turfguy93

Sand capping native soil is the &#128273; to good turf in my opinion!


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## osuturfman

Cross post from a linked topic:

On the issue of "concrete":

Topdressing or "capping" a native soil with sand is a practice that's been around for nearly 100 years here in the US. The vast majority of golf course putting greens built prior to the 1960's are/were native soil greens at construction. From there golf course superintendents have continually topdressed sand directly over the native soil to build up a "cap". See this photo below from Traverse City Golf and Country Club where 22 years of sand topdressing sits atop the native soil from greens construction.



What about doing it all at once you say? Well, a few smart people at Michigan State wondered about that too, specifically on sports fields. What they came up with is a process now known as the Spartan Sand Cap. Please see link below for more description.

http://msue.anr.msu.edu/uploads/236/68678/Sand-Cap-Athletic-Fields.pdf

http://www.stma.org/sites/stma/files/Conference/2012_Conference/Kowalewski_Presentation.pdf

The main issue with capping is you have to commit to keeping the interface between your two layers open. What I mean by that is through mechanical aeration, there must be vertical channels to allow water and roots to move down, as well as air up and down. This could be accomplished with solid tines or hollow tines. Backfilling the channels with sand would be ideal but, is not completely necessary. In either case, choosing a sand with the proper fractions (see size) and angularity (see shape) is very important for long-term success.

With respect to "amending" a clay soil with sand, yes this is where you can get into trouble. As @thegrassfactor alluded to, amendments constitute tilling in or otherwise mechanically combining an amendment material, sand in this case, with the existing soil at a depth of 4-8", typically. Where things can go awry is if too little sand is used to amend and you end up with particle sizing in the soil that is <85% sand. Moreover, the properties of the sand itself, as mentioned above with the capping method, are crucial to the performance of the amended soil.

In either case, I would want to see the sand specs from the vendor on the material you are buying, have a particle size analysis on your existing soil (sand, silt, clay), and then make the best choice on how to move forward.

TL;DR - It's OK to put high-quality, properly sized sand on top of your native soil lawn for leveling/topdressing. If you get a tiller involved, check yourself before you wreck yourself.


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## Delmarva Keith

If I'm understanding what's going on right, the "concrete" issue is filling the sand's interstitial space with clay fines. The high surface area of tiny clay particles sticks to the sand like glue and makes the equivalent of lean mortar.

So sand over clay should not be an issue. Clay over sand would eventually make a big problem. Mixing clay with sand in the right proportions will make a type of bricks.


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## N LA Hacker

Co-wrecked


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## slomo

wardconnor said:


> Exactly folks. Who the crap was it that started the retarded rumor that clay plus sand equals concrete? This is evidence that it is NOT correct.
> 
> That concrete rumor is a real pisser offer for sure.


It's not concrete, it's cement.

slomo


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## Ridgerunner

slomo said:


> wardconnor said:
> 
> 
> 
> Exactly folks. Who the crap was it that started the retarded rumor that clay plus sand equals concrete? This is evidence that it is NOT correct.
> 
> That concrete rumor is a real pisser offer for sure.
> 
> 
> 
> It's not concrete, it's cement.
> 
> slomo
Click to expand...

Nope, it's neither. Depending on the mix ratio, it's just lousy soil.


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## samjonester

Matt Martin stirring the pot tonight

https://youtu.be/Db4BaKLnNy4?t=10m12s


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