Štrková mriežka pre poľné cesty a vjazdy – IBRAN-X®
Vjazd na pole znáša najväčšiu záťaž. Mriežky IBRAN zachytávajú kamenivo, takže poľné vjazdy a poľné cesty zostávajú pevné počas žatvy, silážovania aj mokrej zimy – bez nutnosti dosypávať štrk každú jar.
Prečo je tu vystuženie nevyhnutné
Poľný vjazd je niekoľko metrov, ktoré znášajú najväčšiu záťaž na celom hospodárstve. Každé vozidlo, ktoré pracuje na danom poli, prechádza cez jeden otvor: traktory, prívesy, cisterny, kombajny dodávateľa, veterinár, nákladné auto s krmivom. Prichádzajú z tvrdej cesty, otáčajú sa pod záťažou a vjazdia na pôdu, ktorá na takúto záťaž nikdy nebola stavaná.
Potom príde dážď. Vjazd sa rozmočí, drží vodu a premení sa na hlboké, ťahavé blato, ktoré vás stojí čas pri každom pohybe. Kamenivo nasypané do takéhoto miesta zmizne do jednej sezóny, pretože voľný štrk pod otáčajúcim sa traktorovým kolesom sa jednoducho odtlačí nabok a vtlačí do mäkkej pôdy pod ním.
Bunková mriežka to zmení. Kamenivo je zachytené v uzavretých bunkách, takže sa nemôže posúvať do strán ani vtláčať do podložia. Zaťaženie sa prenáša cez kamenivo do podkladu, namiesto toho, aby kamenivo odsúvalo nabok. Vjazd zostane tam, kde ste ho vybudovali.
To isté platí pozdĺž celej cesty. Zachytené kamenivo nemigruje na krajnice, takže prestanete prerovnávať povrch a prestanete kupovať rovnaké tony opakovane.
Kde to funguje najlepšie
- Poľné vjazdy a brány
- Poľné cesty a okrajové trasy
- Prístupy na dvory a otáčacie plochy
- Brány pre hospodárske zvieratá a priechody cez koridory
- Prístupy k silážnym žľabom a zásobníkom krmiva
- Stanovištia pri napájadlách a kruhových kŕmidlách
- Prístupy na solárne a inžinierske plochy na poľnohospodárskej pôde
- Dočasné a sezónne prístupy, ktoré musia byť obnovené do pôvodného stavu
Prehľad parametrov
| Podkladová vrstva | 150–250 mm zhutneného štrkodrvového podkladu, viac na mäkkej alebo rašelinovej pôde |
| Výplň | Triedená zmes 6–20 mm, hranatá a čistá, vyplnená po úroveň mriežky s 5–10 mm zaslepením povrchu |
| Typické zaťaženie | Traktory a naložené prívesy, cisterny na hnojovicu, kombajny, nákladné autá s krmivom |
| Hospodárske zvieratá | Vhodné pre vjazdy pre hovädzí dobytok a ovce. Pevný povrch, bez rozmočenia, bez stojatej vody |
| Blato na komunikácii | Pevný, voľne odvodňujúci vjazd vynáša na cestu podstatne menej blata |
| Odvodnenie | Plne priepustné. Voda vsakuje namiesto toho, aby stála vo vjazde |
| Životnosť | 25 rokov pri dokumentovanej inštalácii |
| Materiál | 100% recyklovaný polypropylén, vyrobený v EÚ z recyklovaných polymérov |
Problém poľného vjazdu
Stojí za to presne vysvetliť, prečo vjazdy zlyhávajú, keď trasa na oboch stranách od nich vydrží.
V bráne sa dejú tri veci, ktoré sa inde nedejú. Premávka sa sústreďuje: každý pohyb do poľa a z neho prechádza cez tých istých niekoľko metrov. Vozidlá sa otáčajú: riadenie pod záťažou, keď koleso sotva valí, brúsi povrch namiesto toho, aby po ňom prechádzalo. A nastáva prechod z pevného povrchu na mäkký – presne tam, kde je zaťaženie najvyššie.
Preto môže vjazd pohltit dvadsať ton kameniva a v februári byť stále blatiskom. Kamenivo nebolo zachytené, takže každé otáčajúce sa koleso ho posúvalo do strán a nadol do pôdy, ktorá bola už aj tak mäkká.
Zachyťte ho a rovnaké množstvo vydrží desaťročia. Toto je niekoľko štvorcových metrov na hospodárstve, kde sa investícia najviac oplatí.
Ktorá hĺbka mriežky?
Číslo pri mriežke vyjadruje hĺbku vrstvy zachyteného kameniva. Na poľnohospodárskej pôde, kde sú vozidlá ťažké a podložie je často mäkké, je hlbšia vrstva spravidla správna voľba.
- IBRAN®-X50 – naše odporúčanie pre vjazdy, cesty s naloženými prívesmi a cisternami a všade tam, kde sa stroje otáčajú pod záťažou. Hlbšia zachytená vrstva rozkladá zaťaženie na väčšiu plochu pred tým, ako dosiahne podkladovú vrstvu.
- IBRAN®-X40 – pre ľahšie využitie: trasy pre štvorkolky a ATV, pešia a živočíšna premávka, okrajové cesty s príležitostnou dopravou mimo žatvy.
- IBRAN®-X30 – pri pokládke na existujúcu tvrdú cestu alebo tam, kde výška vjazdu musí zodpovedať priľahlej komunikácii.
Ak váhate medzi dvoma možnosťami pri vjazde, zvoľte tú odolnejšiu. Práve toto miesto zlyháva – a zlyháva v najhoršom možnom čase roka.
Výber kameniva
Použite triedenú zmes 6–20 mm, hranatú a čistú. Väčšina odporúčaní uvádza jednu frakciu, no jedná frakcia zanecháva dutiny: rovnomerné kamenivo sa vzájomne opiera a nikdy sa úplne nezhutnuje. Zmes tieto medzery vyplní, pretože menšie kamene sa zaklinia medzi väčšie.
Plne vyplnená bunka prenáša zaťaženie cez kamenivo do podložia. Čiastočne vyplnená bunka ho prenáša cez plast – a pod kolesom naloženého prívesa je tento rozdiel rýchlo viditeľný.
Požiadajte svojho dodávateľa o premyté triedené kamenivo, hranatého tvaru, nie zaoblené. Vyhýbajte sa jemnozrnnému materiálu a odpraškom: viažu povrch a bránia odvodneniu, čo pri vjazde úplne popiera zmysel celého riešenia. Ak neodvádza vodu, bude ju držať – a ak bude držať vodu, opäť sa z toho stane blatiská.
How it goes in
- Set out the area and work out where water currently goes. A gateway is usually the low point of both the field and the road, so it collects from both. Decide now whether you need a cross-fall, a French drain across the entrance, or simply somewhere for it to soak away.
- Dig out the mud. This is the step people skip and it is the one that matters most: soft, poached ground has no bearing capacity, and building on it just buries the problem deeper. Excavate to firm subsoil, however far down that is.
- Lay a woven geotextile across the formation, lapping joins by at least 300mm. On soft agricultural ground this is structural: it stops the sub-base punching down into wet subsoil and stops soil pumping up into your stone.
- Lay and compact the sub-base in 50mm layers. On very soft or peaty ground you may need more depth than a road would take, because you are building a raft rather than a surface.
- Blind with a thin layer of grit sand and screed it level.
- Push-fit the grids together, working from one edge and staggering the joints. Cut to line at the gateposts and verges with a saw.
- Restrain the edges. On a gateway, run the grids wider than the gap itself so the edge restraint sits outside the line the tyres actually take.
- Fill the cells with a 6-20mm graded blend, level plus a 5-10mm blinding, brushing it in so no cell is left hollow.
Full step-by-step detail is in our gravel grid installation guide.
How far into the field?
Further than you think. The instinct is to surface the gap between the posts and stop, but the damage does not stop there.
Vehicles turn as they enter and exit, so the worn area fans out into the field well past the gateway itself. Surface only the gap and you move the mud hole two metres, then have to drive through it to reach the good bit.
As a working rule, extend at least a tractor and trailer length into the field, and wider than the gate opening on both sides. On a busy entrance, take it as far as the turning circle of your largest vehicle. It is the difference between an entrance that works and one that only looks like it does.
Mud on the road
Depositing mud on the public highway is your responsibility, and a wet gateway is where most of it comes from. Tyres pick it up in the entrance and drop it on the road for the next hundred metres.
A firm, free-draining entrance largely removes the source. There is no standing mud for tyres to load up with, so far less leaves the field in the first place. It will not eliminate cleaning duties during a wet harvest, but it changes the scale of the problem, and it takes away the entrance as the cause.
Livestock gateways
Cattle do to a gateway what tractors do, only more often and with higher pressure per hoof. A herd moving twice a day through the same gap will poach it into a slurry whatever the weather does.
A grid surface gives firm footing that drains, which reduces lameness risk and stops the gateway becoming the place stock refuse to walk. Fill level and brush it in well: a smooth, evenly packed surface is what you want underfoot, not proud stone.
Get it right first time
The one thing worth knowing: dig the mud out first.
Every failed gateway on every farm has the same history. Someone tipped stone into a wet hole because it was quicker than excavating, the stone sank into the soft ground over one winter, and by the next year the hole was back and deeper.
Stone laid on mud becomes mud. Excavate to firm ground, get the membrane in, build the sub-base in layers, and the surface above it will still be there in twenty years. Skip it and you will be doing the same job again next autumn, in worse weather, with the harvest waiting.
Ask our engineer
Questions about depths, sub-base, how far to extend an entrance, or which system fits your ground? Ask below, or get in touch directly.
Design your surface
Set out the area, choose a grid and an infill, and see the finished surface. The schedule and the specification follow.
Permeable surface specification
Schedule
Assumptions
Specification
Common Questions
Why does my field entrance keep turning to mud?
Three things happen in a gateway that happen nowhere else. Every movement in and out of the field funnels through the same few metres, vehicles turn under load so the tyre grinds rather than rolls, and there is a transition from a firm surface to a soft one exactly where the load is highest.
Loose stone tipped in gets worked sideways and pressed down into the soft ground beneath, so it disappears within a season. Confining the stone in a cellular grid stops that happening.
Do I need to dig out the mud before laying grids?
Yes, and it is the step that matters most. Soft, poached ground has no bearing capacity, so building on it just buries the problem deeper.
Excavate to firm subsoil however far down that is, lay a woven geotextile, then build the sub-base in compacted layers. Stone laid on mud becomes mud.
How far into the field should I surface a gateway?
Further than the gap itself. Vehicles turn as they enter and exit, so the worn area fans out well past the gateway.
As a working rule, extend at least a tractor and trailer length into the field and wider than the gate opening on both sides. Surface only the gap and you move the mud hole two metres, then have to drive through it to reach the good bit.
Will grids take a loaded trailer, tanker or combine?
Yes, when the sub-base and grid depth are specified for it. The 50mm grid is our recommendation for gateways and tracks carrying loaded trailers and tankers, and anywhere plant turns under load.
Build for the heaviest vehicle that uses the entrance, not the everyday one, because it is the harvest and silage movements that do the damage.
Are grids suitable for livestock gateways?
Yes. Cattle poach a gateway faster than machinery does, because a herd moves through the same gap twice a day at high pressure per hoof.
A grid surface gives firm footing that drains, which reduces lameness risk and stops the gateway becoming the place stock refuse to walk. Fill level and brush it in well so the surface is smooth underfoot rather than proud.
Will this stop mud getting onto the road?
It removes most of the source. Tyres pick mud up in a wet entrance and drop it on the highway for the next hundred metres. A firm, free-draining gateway means there is no standing mud to load up with, so far less leaves the field.
It will not eliminate cleaning duties during a wet harvest, but it changes the scale of the problem.
What sub-base do farm tracks and gateways need?
150mm to 250mm of compacted MOT, and more on soft or peaty ground where you are effectively building a raft rather than a surface. Lay and compact it in 50mm layers.
Ground conditions vary enormously across a farm, so the depth that works at the yard may not be right at the far end of the holding.
What size stone should I fill farm grids with?
A graded blend between 6mm and 20mm, angular and washed. A blend packs tighter than a single size because the smaller stone fills the gaps between the larger.
Avoid fines and scalpings: they bind the surface and stop it draining, which on a gateway defeats the point entirely, because a surface that holds water will be a mud hole again.
Can grids be lifted and reused elsewhere?
Individual grids can be lifted and reinstated, which is useful for temporary or seasonal access, or where a gateway may move.
Bear in mind the sub-base and excavation stay behind, so the reusable element is the grid itself rather than the whole build-up.
How much maintenance does a reinforced gateway need?
Very little. Check levels after the first winter and brush any settled cells back up.
Because the stone is confined there is no annual load of hardcore and no regrading, which is the normal maintenance cycle for an unreinforced entrance. The grid carries a 25 year warranty subject to documented installation.
Ask our engineer
Questions about depths, sub-base, edging or which system fits your project? Ask below.
