Anti-compression stone-and-soil mix and its use

Abstract

Disclosed is a self-fertilizing, anti-compression stone -and-soil mix, suitable for use as a sub-base, especially for road pavements, based on crushed aggregates and mineral-organic components, contributing to the improvement of habitat conditions for the development of trees, increasing the retention potential within PA layers and a space optimizing system for the development of tree roots using such an anti -compression stone-and-soil mix.

Description

[0001] Anti-compression stone-and-soil mix and its use

[0002] The invention relates to a self-fertilizing, anti-compression stone-and-soil mix, which can be used for the production of road pavement sub-base, based on crushed aggregates and mineral- organic components, suitable for improving the habitat conditions for the development of trees, applicable in blue -green infrastructure as a nature -based solution (NBS).

[0003] Background art

[0004] Patent PL173693 discloses an agent for imparting crop values to degraded soil, particularly by the presence of heavy metals. This agent is constituted by carbon fractions and / or clay-carbon fractions. These fractions are separated from mud coal waste. A modified agent further comprises an alkalizing agent in an amount of 0.5-5% dry weight of the waste.

[0005] Patent PL209279 discloses a method of processing the soil environment for plants, especially for trees, characterized in that a gel mixture is introduced into the area of active roots. To introduce the gel mixture, a preliminary opening is made and / or a lance is introduced into the soil, through which the gel mixture is injected under a pressure of 2.5 to 10 kg / cm2, under the surface of a ring defined by 4-^15 trunk diameters, preferably in a width band b on the perimeter of the crown projection on the soil surface. The gel mixture is a hydrated gel or a hydrated gel with the addition of nutrients and / or plant protection agents and / or mycorrhizal fungi. The method and the kit are particularly useful for saving historic old trees, as well as individual trees constituting natural monuments.

[0006] Patent PL242481 discloses a mix based on fine rock fractions fertilizing the soil and supporting plant cultivation, intended for use for crop plants, as a natural soil improving agent, which is characterized in that it consists of fine gneiss fractions from the Doboszowice 1 deposit in the form of gneiss dust with a grain size of up to 0.05 mm in an amount of 10.00% w / w to 40.00% w / w and gneiss crushed sand with a grain size of 0.05 to 0.50 mm in an amount of 60.0% w / w to 90% w / w.

[0007] The main challenge when preparing anti-compression systems is to develop the right proportions of ingredients, because excess soil causes the mixture to settle, while excess stones - improper water capacity and nutrient content of the substrate.

[0008] The problem in the variants used so far is the depletion of nutrients in stone-and-soil subbases that function under pavements, without the possibility of organic matter circulation. The practical use of known anti-compression systems is limited by their numerous imperfections: i) offering too high pH, which hinders or blocks the absorption of nutrients by plants, ii) providing too low microbiological activity, iii) obtaining the necessary nutritional properties involves the need to use peat and other natural ingredients, the acquisition of which results in the destruction of the natural environment, iv) the need to use non-organic components, e.g. plastic boxes or insufficient use of the potential of bio-recycled materials.

[0009] In the case of urban greenery, a serious problem is the limitation of space for plant growth, in particular the space available for the development of the tree root system.

[0010] The natural conditions of tree growth allow to achieve proper development and, consequently, the highest level of ecosystem services.

[0011] Technical Problem

[0012] The problem to be solved by the present invention is the development of a new anticompression stone -and-soil mix, which will provide similar to natural, optimal soil conditions for the growth of trees and space for the development of their root system, while allowing for the accumulation of rainwater, and will also provide the mechanical strength required from materials used as road pavement sub-base. This type of mixture is particularly desirable for the development and care of wood stands in highly urbanized areas.

[0013] In particular, the object of the invention is to provide, over a longer period of time, the availability of nutrients necessary for the proper development and growth of trees (Ca, Mg, K, P, Na, N to a lesser extent), which over time should be gradually released into the soil solution. Earthy substrate of the soil-and-stone mix should be characterized by the ability to exchange CEC cations of more than 10 cmol / kg. It is desirable that at the initial period of use the sub-base according to the invention provides a substrate very rich in available phosphorus (from 175.9 to 264.4 mg / kg d.m. of soil), available magnesium (from 140.8 to 320.8 mg / kg d.m. of soil) and available potassium (from 624.4 to 1245.8 mg / kg d.m. of soil). Large amounts of plant nutrients will provide a good start for planted trees. At the same time, such a high abundance is desirable only in the initial period of tree cultivation and may later be significantly reduced. An important parameter of substrate fertility is the C:N ratio, which should not be higher than 33: 1. Too high a C:N ratio leads to nitrogen deficiency and slows down the microbial processes that are responsible for the metabolism of organic matter, weathering of minerals, transformation of nitrogen and many others.

[0014] Another object of the invention is to provide an anti-compression sub-base having a rainwater retention capacity of at least 0.17 m3 / m2, preferably above 0.21 m3 / m2, most preferably above 0.29 m3 / m2.

[0015] Another object of the invention is to provide an anti -compression sub-base suitable for the production of road pavements that can be loaded with a 100 kN axis with a KR1-KR3 traffic volume according to the traffic classification.

[0016] Summary of the invention

[0017] Surprisingly, the aforementioned comprehensive technical object of the invention has been achieved by the present invention.

[0018] The subject of the invention is an anti-compression stone -and-soil mix and its uses, which have been defined in detail in the appended claims.

[0019] Advantages of the invention

[0020] The present invention has numerous advantages.

[0021] The anti -compression sub-base for pavements constituting an embodiment of the subject invention (also referred to in the further part of the description as "PA") allows for the extension of the root zone of trees by communication zones (pedestrian and mobile pavements) . It can be used to enlarge the box of newly planted trees, or to improve the habitat conditions of existing trees. It provides growth conditions comparable to natural conditions, which translates into a long and safe growth of trees, consistent with their developmental phases, including the natural aging phase.

[0022] The PA is built in such a way that it allows water to be taken up by the fine roots, dividing the system into a vegetation top layer in which the roots develop and a periodically flooded lower aeration-infiltration layer with the possibility of infiltration within the pavement trench.

[0023] The subject PA has a high rainwater retention capacity of at least 0.17 m3 / m2, preferably above 0.21 m3 / m2, most preferably above 0.29 m3 / m2.

[0024] At the same time, the pavement structures manufactured with the use of the PA can be loaded with a 100 kN axis with a KR1-KR3 traffic volume according to the traffic classification. The tests carried out on the upper layer of the anti -compression sub-base showed the obtained load capacity of E2+ 60 MPa to 132 MPa, which corresponds to the requirements of the substrate load capacity for road pavement structures according to the Catalogues (Catalogue of typical flexible and semi-rigid pavement structures, Annex to Regulation No. 31 of the General Director for National Roads and Motorways of 16.06.2014 and the Catalogue of typical rigid pavement structures, Annex to Regulation No. 30 of the General Director for National Roads and Motorways of 16.06.2014), which should amount to E2>50-80 MPa.

[0025] The use of the invention allows to solve the collision between the need to preserve or plant trees and the need to expand the communication infrastructure. In the case of the use of the invention, pavement sub-bases enabling communication (pedestrian paths, parking lots, roads or squares) perform the functions of supporting the development of existing and newly planted trees for their long and safe development. This allows for an increase in the number of trees growing in the urban environment, especially in the most difficult locations for their development, covered with pavements, and thus an increase in tree crown cover, translating into an improvement in the quality of life of urban residents.

[0026] The subject of the invention was presented by means of examples on the drawing, wherein: fig. la is a plan view of an assembly diagram of the compression system according to the invention, in which the open box is enlarged by a closed box; fig. lb is a plan view of an assembly diagram of the compression system according to the invention, in which the open box is enlarged by a green space through a root path; fig. 1c is a plan view of an assembly diagram of the compression system according to the invention, in which the closed box is enlarged by a green space for the roots through a root path; fig. 2a is a section view through the anti-compression system according to the invention along the axis of the box, in a variant of planting new trees; fig. 2b is a section view through the anti -compression system according to the invention in front of the box face, in a variant of planting new trees; fig. 3a is a section view through the anti-compression system according to the invention along the root path, in a variant for existing trees; fig. 3b is a section view through the anti-compression system according to the invention along the axis of the chamber, in a variant for existing trees;

[0027] Detailed description of preferred embodiments of the invention

[0028] An embodiment of the invention is a pavement sub-base, which consists of two layers of aggregates, silted successively during construction with a soil substrate. The exemplary PA is made of two layers of crushed aggregate, and in a preferred embodiment it is additionally provided with an aeration and irrigation chamber, which provides oxygen access to the layers of the pavement sub-base and collects water from the pavement.

[0029] Preferably, the anti -compression sub-base is provided with at least one overflow to a storm system, controlling the height of the water table within the system sub-base (pavement sub-base built of two layers of aggregate), which allows water to be taken up by fine roots, dividing PA into a vegetation layer in which the roots develop and an aeration-infiltration layer.

[0030] Preferably, the aggregate used to obtain the PA is a gabbro rock, counteracting the compaction of the previously washed-in substrate and maintaining appropriate air-water ratios, and through the occurring airing processes ensuring fertilization supporting the growth of the plant root system. The basic constitution of the soil composition comprised in the PA is based on organic compounds comprised in the substrate.

[0031] Preferably, the soil substrate for washing into the aggregate is composed of a mixture of leaf soil compost ( 1 part), green compost (3.8 parts), gabbro meal ( 1 ) and 16 parts of a mineral mix of earthy substrate (volumetric ratio - bulk - air-dry mass), with a content of the substrate: clay in the mineral part not exceeding 8%, and sand (granulometric composition of sandy clay type having clay content of 5 to 8%, dust of 32-38%, sand of 57 to 62% parts by weight). The following are divided into fractions in the mineral part of the substrate: very thick sand 2.0-1.0 mm - 0%, thick sand 1.0-0.5 mm - 6.6%, medium sand 0.5-0.25 mm - 15.4%, fine sand 0.25-0.1 mm - 19.3%, very fine sand 0.1-0.05 mm - 18%, (sand fraction 2.0-0.05mm - 59%), dust 0.05-0.02mm - 20%, dust 0.02- 0.006mm - 11%, dust 0.006-0.002 - 4% (dust fraction 0.05-0.002mm - 35%) (clay fraction <0.002 mm - 6%) (content of components in the mineral part of the substrate by volume - %) (granulometric group gp).

[0032] The proposed granulometric composition of the earthy substrate with a clay content of 5 to 8% ensures appropriate sorption (storage of plant nutrients), water-air and microbiological properties. These properties were enhanced by adding a significant amount of organic matter to the substrate in the form of green compost and leaf soil compost. The introduction of leaf soil compost and green compost with microbiological properties similar to those of forests to the earthy substrate is to improve their microbiological properties.

[0033] The soil substrate has the following chemical properties: pH up to 7.5, salinity 1.35 [in g NaCl / 1], organic matter content 4.5% [in % d.m.]. (Substrate salinity optimally 1.5 - 5.0 mS / cm (1500 - 5000 pS / cm) or less than 1 ml NaCl / 1 water). Over time, as the organic mass is oxidized, and due to the uptake of alkaline cations (e.g.: Ca and Mg) by the root system of the trees and their elution by rainwater, the pH of the substrate will decrease.

[0034] Preferably, the aeration and irrigation chamber providing oxygen access to the sub-base for pavements is mounted on half the thickness of the aeration layer of the aggregate, which increases the potential for infdtration and aeration of the sub-base.

[0035] Preferably, the soil substrate is composed of mineral and organic components providing nutrients for the development of tree roots available immediately after PA placement and in the long term due to erosion processes resulting in slow release of the rock components used to make the substrate. The nutrient content of the substrate can also be regulated by mineral fertilization, but this is more complicated in the case of deep tree cultivation. When preparing earthy substrates, products in the form of ground rocks such as gabbro were used, which ensure the availability of nutrients (Ca, Mg, K, P, Na, N to a lesser extent) over a longer period of time (several years). The rocks selected for the preparation of earthy substrates comprise significant amounts of alkaline cations, which are gradually released into the soil solution during the weathering process. Earthy substrate of the soil-and-stone mix should be characterized by the ability to exchange CEC cations of more than 10 cmol / kg. In the prepared CEC substrates, it ranges from 23.5 to 39.2 cmol / kg. At the same time, the sorption complex of the earthy substrate is saturated mainly with alkaline cations, the hydrolytic acidity due to the pH is negligible. In the sorption complex, Ca is present in the largest amounts, followed by Mg and K, and Na in the smallest amounts. The prepared substrates according to IUNG (1990) are very rich in available phosphorus (from 175.9 to 264.4 mg / kg d.m. of soil), available magnesium (from 140.8 to 320.8 mg / kg d.m. of soil) and available potassium (from 624.4 to 1245.8 mg / kg d.m. of soil). Large amounts of plant nutrients will provide a good start for planted trees. At the same time, such a high abundance occurs in the initial period of tree cultivation, later undergoing a significant decline. After some time, the weathering rocks will be the main source of these elements (Macroelement content in the earthy substrate: exchangeable cations: Ca 32.2 m, Mg 3.22, K 3.12, 0.70 Na, CEC cmol / kg 39.2, P availability 231.8, K 721.6, Mg 161.2).

[0036] Preferably, sub-base layers made of: a vegetation layer of crushed aggregate made of gabbro rocks 31.5 / 63 with filling after compaction with silting mix, thickness 20 cm (vegetation layer), and an aeration layer of 80 / 150 crushed aggregate made of gabbro rock, minimum thickness 30 cm and maximum 40 cm with filling after compaction with silting mix (aeration-infiltration layer), release ions from the surface of the crushed aggregate grains in the phase of depletion of nutrients within the substrate, feeding the roots of trees in an indefinite time perspective, which solves the problem of depletion of nutrients for the development of trees within the pavement enclosed in the excavation under the pavement of the sub-base layers.

[0037] In alternative embodiments, the PA gabbro rock of the 31.5 / 63 fraction and of 80-150 mm can be replaced with analogous fractions of aggregate obtained from rocks characterized by similar ion release properties in the weathering process, such as: basalt, diabase, diorite, granodiorite, porphyry or mixtures thereof.

[0038] Preferably, the pavement sub-base prepared according to the invention provides the required loadbearing capacity of the pavement, and it should be surrounded by a standard built resistance (road curb or edge on a concrete footing), with a volume adapted to the needs of trees, in particular with square, rectangular or any horizontal projection, with a pavement trenching depth (excluding wearing course) of 50 cm, providing a load-bearing capacity of E2>80MPa, and an appropriate compaction level: the value of the deformation index E2 / E1 <4.0 mm, and with a trenching depth of 60 cm or 70 cm (with a structural layer having thickness of 10 cm), providing a load-bearing capacity E2>80MPa, and an appropriate compaction level: the value of the deformation index E2 / E1<2.2). In preferred embodiments, the pavement structures with the PA can be loaded with a 100 kN axis with a KR1-KR3 traffic volume according to the traffic classification. The tests carried out on the upper layer of the anti-compression sub-base showed the obtained load capacity of E2+ 60 MPa to 132 MPa, which corresponds to the requirements of the substrate load capacity for road pavement structures according to the Catalogues (Catalogue of typical flexible and semi-rigid pavement structures, Annex to Regulation No. 31 of the General Director for National Roads and Motorways of 16.06.2014 and the Catalogue of typical rigid pavement structures, Annex to Regulation No. 30 of the General Director for National Roads and Motorways of 16.06.2014), which should amount to E2>50-80 MPa. The test carried out on an aggregate sub-base constituting a preferred embodiment of the invention showed a load-bearing capacity of E2= 172 MPa, which corresponds to the load-bearing capacity of the base according to the catalogues for structures loaded with heavy traffic >KR3.

[0039] In a preferred embodiment, leaf soil compost and / or green compost with microbiological properties similar to those of forests were introduced into the earthy substrate, which significantly improves the properties and microbiological potential, crucial for ensuring the long-term proper development of trees for roots of which the sub-base will be available.

[0040] Preferably, the PA was prepared using an earthy substrate in which the introduction of low and high peat was abandoned, which is preferred due to the ecological aspect of not destroying valuable habitats.

[0041] Preferably, the earthy substrates of the stone-and-soil mix are characterized by a C:N ratio of 13: 1 to 30: 1. An important parameter of substrate fertility is the C:N ratio, which should not be higher than 33: 1. Too high a C:N ratio is a sign of nitrogen deficiency and the slowing down of the microbial processes that are responsible for the metabolism of organic matter, weathering of minerals, transformation of nitrogen and many others.

[0042] Preferably, the PA comprises gabbro meal as an ingredient enriching in the long-acting minerals, mainly alkaline cations.

[0043] Preferred embodiments present PA variants differing in the thickness of the sub-base layers, which correspond to different types of PA intended for the production of pavements differing in traffic load.

[0044] PA is characterized by self-fertilizing properties, supporting the development of trees in the perspective of their entire life period up to the stage of old age and dying.

[0045] Examples

[0046] Example 1. Anti-compression stone-and-soil mix.

[0047] An anti -compression stone-and-soil mix, which can be used as a sub-base for pavements, in the basic version is made of two layers of crushed aggregate from rock, especially the gabbro: i) an upper vegetation layer, ii) a lower aeration-infiltration layer.

[0048] Vegetation layer

[0049] The vegetation layer of the anti-compression sub-base is made of crushed aggregate from the gabbro rocks of the 31.5 / 63 mm fraction. This layer is compacted after laying and then silted with a soil substrate of the composition described below.

[0050] Aeration-infiltration layer The infiltration layer of the sub-base is made of crushed aggregate from the gabbro rocks of the 80 / 150 mm fraction. It is permissible to use other fractions with aggregate grain sizes between 80 and 150 mm, for example 80 / 130 mm fraction. This layer is compacted after laying and then silted with a soil substrate of the composition described below.

[0051] Soil substrate

[0052] The substrate for washing into aggregate layers composed of: i) a mixture of earthy compost (9.244%), green compost (23.416%), gabbro meal (3.73%), ii) and the mineral part of the soil substrate mix with the content of clay, dust and sand (granulometric composition of the sandy loam type with the content of clay from 5 to 8%, dust from 32-38%, sand from 57 to 62% by weight) (63.60% content in the substrate). Content of ingredients by volume (%), (granulometric group gp).

[0053] The granulometric composition of the earthy substrate shall comprise 5 to 8% clay, which ensures appropriate sorption (storage of plant nutrients), water-air and microbiological properties. These properties were enhanced by adding to the substrate a significant amount of organic matter in the form of compost and green compost. The introduction of compost and green compost with microbiological properties similar to those of forests to the earthy substrate is to improve their microbiological properties.

[0054] The nutrient content of the substrate can be regulated by mineral fertilization, although this is more complicated in the case of deep tree cultivation.

[0055] Soil substrate was developed using ground gabbro rocks, which shall ensure the availability of nutrients (Ca, Mg, K, P, Na, N to a lesser extent) over a longer period of time (several years). The rocks selected for the preparation of earthy substrate comprise significant amounts of alkaline cations, which will be gradually released into the soil solution during the weathering process. The PA soil substrate should be characterized by the ability to exchange CEC cations of more than 10 cmol / kg. In the prepared CEC substrate, a value of 11 cmol / kg was obtained. At the same time, the sorption complex of the soil substrate is saturated mainly with alkaline cations, the hydrolytic acidity due to the pH is negligible. In the sorption complex, Ca is present in the largest amounts, followed by Mg and K, and Na in the smallest amounts. The prepared substrates according to IUNG (1990) are very rich in available phosphorus (from 175.9 to 264.4 mg / kg d.m. of soil), available magnesium (from 140.8 to 320.8 mg / kg d.m. of soil) and available potassium (from 624.4 to 1245.8 mg / kg d.m. of soil). Large amounts of plant nutrients will provide a good start for planted trees. At the same time, such a high abundance occurs in the initial period of tree cultivation, later undergoing a significant decline. At the same time, the weathering rocks will continue to be the source of these elements (content of macroelements in the soil substrate: exchangeable cations: Ca 32.2 m, Mg 3.22, K 3.12, 0.70 Na, CEC cmol / kg 39.2, P availability 231.8, K 721.6, Mg 161.2).

[0056] In the phase of depletion of nutrients within the substrate, the vegetation and aerationinfiltration layers release ions from their surface, feeding the roots of trees in an indefinite time perspective, which, in the long term, solves the problem of depletion of nutrients for the development of trees within the pavement enclosed in the excavation under the pavement of the sub-base layers.

[0057] The soil substrate has the following chemical properties: pH up to 7.5, substrate salinity between 1.5 - 5.0 mS / cm (1500 - 5000 pS / cm) or less than 1 ml NaCl / 1 water, the organic matter content 4-6% [in % d.m.]. It shall be emphasized that over time, as the organic mass is oxidized, and due to the uptake of alkaline cations (e.g.: Ca and Mg) by the root system of the trees and their elution by rainwater, the pH of the substrate will decrease.

[0058] Example 2. Method of obtaining a road pavement sub-base using the anti-compression stone- and-soil mix according to the invention.

[0059] The example concerns obtaining a road pavement sub-base using the anti-compression stone-and- soil mix (PA) according to the invention, securing the growth conditions for existing trees.

[0060] The PA is laid in the vicinity of boxes of newly planted trees. The box is built in a way that allows the roots of the tree to grow from the box to the PA.

[0061] The PA is laid in the root systems of existing trees, after their uncovering using known gardening methods that do not damage the roots, such as the AirSpade method. The edges of the pavement in the vicinity of the trunk of the existing tree are built over the roots of the existing tree, without cutting them, in a way that allows the roots to grow into the PA.

[0062] In the pavement trench, an aeration-infiltration layer PA is laid and compacted with the use of standard plate compactors. Then this layer is silted with a soil substrate. The soil substrate is laid in layers of 3 cm and washed in by pouring with a free stream of water.

[0063] Further, a PA vegetation layer is laid and compacted with the use of standard plate compactors. Then this layer is silted with a soil substrate. The substrate is laid in layers of 3 cm and washed in by pouring with a free stream of water. The volume ratio of the stone fraction to the substrate fraction in the anti-compression sub-base is preferably 5: 1.

[0064] In a preferred embodiment the PA it is additionally provided with an aeration and irrigation chamber, which provides oxygen access to the layers of the pavement sub-base and collects water from the pavement. Preferably, the chamber is mounted in the PA pavement, in the number of at least 1 pc / tree, in the immediate vicinity of the tree.

[0065] Example 3. Sub-bases for road pavements with different load-bearing capacities

[0066] The anti-compression sub-base according to the invention can be used as a sub-base for roads, parking lots, sidewalks, pedestrian paths, pedestrian and mobile pavements and bicycle paths. The exemplary variants of the sub-base described below differ in the thickness of the vegetation layer (WW) and the aeration-infdtration layer (WAI) and the possible presence of an additional structural layer (WK). All these sub-bases are suitable for carrying loads of pedestrian and car traffic.

[0067] The selection of the applied top wearing course should be adapted to the expected traffic intensity. In the case of KRl-type pavements (pedestrian traffic, passenger cars and occasional entry of a heavy car), mineral top layers may be used. In the case of KR3-type pavements (pedestrian traffic, passenger cars and heavy traffic - trucks), top layers comprising concrete, asphalt and stone pavements, solid or made of slabs or paving stones, may be used.

[0068] The thickness of the layers also affects the PA retention capacity, which should be adapted to the needs related to the need to manage rainwater.

[0069] As examples of sub-base designs for various purposes (load-bearing capacity and retention capacity), variants I-III were prepared, and are presented below.

[0070] Variant I cm For the obtained pavement variants, load-bearing capacity measurements according to PN-S-02205 standard1’.and retention capacity measurements were performed.

[0071] Table 1. Characteristics of PA variants PN-S-02205:1998 Motor roads. Earthworks. Requirements and tests.

[0072] Conclusions

[0073] When using the sub-base according to the invention, a load-bearing capacity greater than in the case of a classic sub-base structure was obtained.

[0074] PA of thickness 50-^60 cm on the proposed G4 substrate subject to frost-heave provides the load capacity required for the E2>80 MPa road substrate. Due to the thickness of 50^60 cm, PA protects against frost substrates subject to frost-heave or low-frost-susceptible substrates belonging to the G2AIi4 group, so they can be treated as an anti-frost layer. The PA can also act as an improved substrate in the context of its small retention properties. The PA may form a road substrate for the foundation of the road pavement structure. The thickness and arrangement of the overlying layers should result from the expected traffic load. The subject structures according to the invention meet the requirements of the structure load for pedestrian and light car traffic with occasional entry of a heavy car (with mineral pavement), and pedestrian, light and heavy traffic with the use of hard pavements (of asphalt, concrete, paving stones) - PA may be loaded with heavy traffic (trucks) if appropriate traffic adapted to the planned traffic on the structure layer (variants II and III) is provided. Example 4. Optimization of the composition of the soil substrate.

[0075] Initial research covered 15 products intended for the composition of earthy substrate for the so-called stone-and-soil mix, intended for a substrate for planting trees in the urban and industrial environment.

[0076] The following components were used to compose the earthy substrate for the soil-and-stone mix:

[0077] 1. Granulated biohumus;

[0078] 2. Compost (leaf soil);

[0079] 3. Compost from chips;

[0080] 4. Low peat;

[0081] 5. High peat;

[0082] 6. Green compost;

[0083] 7. Mushroom compost;

[0084] 8. Tuff;

[0085] 9. Peat top (peat earth);

[0086] 10. Humic soil 2;

[0087] 11. Humic soil 1 ;

[0088] 12. Non-humic soil;

[0089] 13. Basalt meal;

[0090] 14. Zeolite;

[0091] 15. Gabbro meal.

[0092] In order to obtain the soil substrate mix, the air-dry components were ground in a ceramic mortar and sieved through a 2 mm diameter sieve to separate the skeletal parts. In 15 components, the pH in H2O and KC1 was determined - potentiometrically, salinity - conductometrically, organic matter content by annealing samples at

[0093] 550°C, and CaCCL content by field method by pouring samples with 10% HC1 and observing the intensity of foaming. On the basis of morphological features and the obtained results - loss of matter on annealing, pH and salinity, 9 (1, 2, 3, 6, 8, 11, 13, 14 and 15) from 15 components were selected to create earthy substrates for the soil-and-stone mix. In the selected 9 components, the total content of carbon and nitrogen was also determined using the Costech elemental analyzer and the bulk density using Kopecki cylinders with a volume of 100 cm3.

[0094] After determining the properties ofthe 9 components (1, 2, 3, 6, 8, 11, 13, H and 15). 15 different compositions of earthy substrates intended for composing the soil-and-stone mix were prepared from them. The following are marked in earthy substrates:

[0095] - granulometric composition using the Casagrande's aerometric method with Proszyriski modification, the percentage of sand subfraction was determined using a set of sieves with variable mesh size; granulometric groups were determined according to PTG (2008);

[0096] - content of calcium carbonates (CaCCE) by the Scheibler method;

[0097] - soil pH in water (H2O) and potassium chloride (KC1) solution with a concentration of 1 mol dm" 3 - by potentiometric method using an Orion 420A pH meter with a combined electrode;

[0098] - organic matter content as mass loss during annealing at 550°C;

[0099] - salinity - conductometrically;

[0100] - available phosphorus and potassium - by the Egner-Riehm method and available magnesium - by the Schachtschabel method. The assessment of the content of bioavailable macroelements in the soil was made on the basis of IUNG (1990) limiting numbers;

[0101] - content of exchangeable cations: Ca2+, Mg2+, K+, Na+- extracted with an ammonium acetate solution with a concentration of 1 mol dm'3, and then determined with an ASA Unicam Solaar 929 spectrometer;

[0102] - the content of total forms of carbon (C), nitrogen (N) and sulphur (S) using the Costech elemental analyzer;

[0103] The determined properties allowed to calculate:

[0104] - C:N ratio;

[0105] - sum of exchangeable cations (CEC) according to the formula:

[0106] CEC= Ca+Mg+Na+K [cmol / kg of soil]

[0107] The morphological characteristics and properties ofthe 15 components intended for the production of the soil-and-stone mix substrate composition were determined. Table 2. The basic properties of the ingredients. determined, ns - not detected

[0108] Out of the 15 components, 9 were selected, from which 15 composition variants of soil substrates were prepared. Two of the tested components (1, 2, 3, 6, 8, 11, 13, 14 and 15) were selected, which will form the main material of the soil substrate composition: component 11 (clay humus soil 1) and component 6 (green compost). In several cases, product 1 (granulated humus) was used interchangeably with component 2. These components ensure appropriate grain size of the earthy substrate, pH and humus content. The remaining components of the selected ones (3, 6, 8, 13, 14, 15) formed, in individual variants ofthe soil substrate composition, a fertilizer supplement. The complementary ingredients have been selected on the basis of their different properties and the fertilizer role they will play in the soil substrate. Components No. 8, 13, 14 and 15 are natural rocks characterized by a high content of alkaline cations (Ca, Mg, K, Na) and micronutrients (Fe, Mn), which will gradually be released into the soil environment. In addition, component 14 is characterized by high sorption capabilities (improves resistance to chemical contaminants). Components 2 (compost from the so-called leaf soil) and 3 (compost from chips) were selected for their specific organic material, which is wood waste (leaves, bark, sawdust, sticks) with earthy parts, which will constitute a microbiological vaccine of forest habitats (microbiological tests required), which will facilitate the rooting of trees.

[0109] The quantitative selection of individual components was made mainly on the basis of the content of organic matter within them. To a lesser extent, the pH was taken into account because the provided components were characterized by a neutral or alkaline pH, and only component 11 had a slightly acidic pH, while component 5 was strongly acidic. Component 11 was used as the main component of the soil substrate mix, while component 5 was abandoned due to its unfavorable properties (such as pH, difficult availability). Based on the content of organic matter in selected components, their preferred ratios in the soil substrate composition were calculated (Table 3).

[0110] Table 3. Test soil substrate compositions The starting point for the preparation of the soil substrate were the assumptions according to which the earthy parts of the stone-and-soil mix should show the granulometric composition of sandy clay with a percentage share of individual subfractions:

[0111] - clay (clay according to Polish standards): 0.001-0.002 mm: 0-2%,

[0112] - fine fen soil (fine dust according to Polish standards): 0,002-0,006 mm:

[0113] 2-6%,

[0114] - medium fen soil (medium dust according to Polish standards): 0,006-

[0115] 0,02 mm: 8-16%,

[0116] - coarse fen soil (coarse dust according to Polish standards): 0,02-0,06 mm: 13-26%,

[0117] - fine sand: 0,06-0,2 mm: 25-33%,

[0118] - medium sand: 0,2-0, 6 mm: 11-24%,

[0119] - coarse sand: 0,6-2 mm: 0-16%,

[0120] - fine gravel: 2-6 mm: 0-10%

[0121] Results

[0122] Variants 5, 6 and 15 were considered preferred for the development of tree roots.

[0123] As a result of the analyzes, the most preferred substrate for washing into the aggregate (variant No. 15) was selected in terms of providing conditions for the development of roots, composed of (quantities given as a volumetric ratio - bulk - air-dry mass) a mixture of leaf soil compost (1 part), green compost (3.8 parts), gabbro meal (1 part) and a part of a mineral mix of earthy substrate (16 parts of the content in the substrate) with a clay content not exceeding 8% and sand (granulometric composition of sandy clay type with a clay content of 5 to 8%, dust of 32- 38%, sand of 57 to 62% by weight) (granulometric group gp). The proposed granulometric composition of the earthy substrate with a clay content of 5 to 8% will ensure appropriate sorption (storage of plant nutrients), water-air and microbiological properties. These properties were enhanced by adding a significant amount of organic matter to the substrate in the form of green compost and leaf soil compost. The introduction of leaf soil compost and green compost with microbiological properties similar to those of forests to the earthy substrate is to improve their microbiological properties. Variants 5, 6 and 15 were tested for microbiological potential. In these studies, they also showed preferable properties aiding the tree growth.

[0124] Conclusions

[0125] Out of the 15 tested composition variants of soil substrates, the 3 with the highest potential were selected. All variants (5,6, and 15) are preferable for the development of tree roots and may be suitable for silting aggregates in an anti -compression sub-base.

[0126] All substrate variants are composed of mineral and organic components. They do not comprise peat, which has a beneficial effect on environmental protection, especially ecosystems of key importance for retention. Compositions 5,6, and 15 comprise green compost, which is currently a difficult to manage urban waste, the use of which supports the principles of circular economy. Variant No. 15 was selected due to the optimal, most preferred of the three tested, properties for the development of tree roots, in accordance with the requirements of horticulture (C:N = 11). Variants 5 (C:N = 17) and 6 (C:N = 14) are applicable in a contaminated or saline habitat due to the high buffer properties (ability to absorb pollutants in the substrate sorption complex).

[0127] An important objective of the invention was to provide a self-fertilizing substrate suitable for tree growth.

[0128] The gabbro rock used in a particularly preferred embodiment of the invention variant 15 is an alkaline, intrusive, medium- or coarse-grained rock. It belongs to the group of diorytoids and gabroids. It comprises >90% of plagioclases in relation to potassium feldspars (up to 10%), up to 5% of quartz, 25-60% of dark minerals. On the QAPF classification diagram, gabbro occupies field 10 together with diorite. Gabbro plagioclases comprise >50% of the anorthit particle (labradorite , bytownite, anorthite). Gabbro comprises >30% of dark minerals. Pyroxenes dominate among dark minerals in gabbro (L. von Buch, 1810).

[0129] An important parameter of the soil substrate is the nutrient content. The nutrient content of the substrate can be easily regulated by mineral fertilization, although this is more complicated in the case of deep tree cultivation, especially with root systems covered with an impermeable pavement, it is complicated and has not yet brought the expected effects. In variant 15, in the composition of the soil substrate, the addition of gabbro meal was used: the pulverized dusty material can be used directly to manufacture the substrate of the stone-and-soil mix.

[0130] It is a rock rich in alkaline cations.

[0131] When preparing soil substrates, it is worth using products in the form of ground rocks such as gabbro (but also tuff and basalt, as used in variants 5 and 6), which are to ensure the availability of nutrients (Ca, Mg, K, P, Na, N to a lesser extent) over a longer period of time (several years). The rocks selected for the preparation of earthy substrates comprise significant amounts of alkaline cations, which will be gradually released into the soil solution during the weathering process. In the longer term, fertilization will ensure the weathering of rocks of larger fractions, from which the load-bearing layers of the anti-compression sub-base are built.

[0132] The correctly prepared soil substrate should be characterized by the ability to exchange CEC cations of more than 10 cmol / kg. In the prepared CEC substrates, it ranges from 23.5 to 39.2 cmol / kg. At the same time, the sorption complex of the earthy substrate is saturated mainly with alkaline cations, the hydrolytic acidity due to the pH is negligible. In the sorption complex, Ca is present in the largest amounts, followed by Mg and K, and Na in the smallest amounts.

[0133] Moreover, the soil substrate should have an optimal pH in the range of 3.5- 8.2, preferably 5.5-6.3. The prepared earthy substrates have a pH in KC1 of 6.49 to 6.95 (it is a slightly acidic to neutral pH), while the pH in H2O generally does not exceed 7.2 (neutral pH). The relatively high pH of the substrates (slightly above the optimal values) generally results from the alkaline pH of the products (composts, ground rocks) used to fertilize the substrates, but this is not due to the presence of CaCOa in them. It shall be emphasized that over time, as the organic mass is oxidized, and due to the uptake of alkaline cations (e.g.: Ca and Mg) by the root system of the trees and their elution by rainwater, the pH of the substrate will decrease.

[0134] An important parameter of substrate fertility is the C:N ratio, which should not be higher than 33: 1. Too high a C:N ratio is a sign of nitrogen deficiency and the slowing down of the microbial processes that are responsible for the metabolism of organic matter, weathering of minerals, transformation of nitrogen and many others. The prepared earthy substrates of the stone-and-soil mix are characterized by a C :N ratio of 11 : 1 (variant 15 - basic) to 14 : 1 (variant 6) and 17: 1 (variant 5). Variant No. 15 is characterized by the most preferred value of the C:N coefficient.

[0135] A field experiment was also conducted using the invention. The construction of parking spaces was carried out using 4 variants of the sub-base with the laying of the wearing course: type I, type II, type III (variants of the anti-compression sub-base according to the invention), and type IV (standard pavement sub-base, without the possibility of developing tree roots under the pavement) with the laying of edges as well as the conducting supplementary works consisting in the installation of an aeration and irrigation inspection chamber and a drainage chamber. Variants I, II and III were silted with the substrate. A box was made in the vicinity of parking spaces and a tree was planted.

[0136] The experiment showed the correct, long-term development and better growth of trees in the vicinity of the areas of variants I, II and III compared to the tree growing in the vicinity of variant IV (control).

[0137] Example 5. Measurement of retention capacity.

[0138] The test was carried out under laboratory conditions on models made of the supplied materials, on the basis of design data and information on the amount of aggregates and silting mix used during construction. The wearing course was not included in the study. The volume of water that can be retained in the profile was determined only for the sub-base layers. The test was carried out individually for individual layers of the sub-base and for the layer arrangement. The results summarized in Tables 4-6 for the layers are mean values from three measurements, wherein the results from individual measurements were repeatable. The value for the entire layer arrangement is given as a range determined on the basis of measurements made for individual layers and the layer arrangement.

[0139] Table 4. Retention capacity of the parking lot sub-base Type 1

[0140] Table 5. Retention capacity of the parking lot sub-base Type 2 Table 6. Retention capacity of the parking lot sub-base Type 3

[0141] Depending on the layer arrangement, the anti-compression sub-base is characterized by a retention capacity of 0.17 to 0.31 m3 / m2).

[0142] Example 6. Tree box optimization

[0143] An example relates to the provision of an optimal volume and / or surface of the box in insufficient habitat conditions of trees (impermeable pavements, too small volume of substrate for tree development, barriers to development) using the anti-compression stone-and-soil mix of the invention, used for the purpose of:

[0144] - enlargement of the tree box under the pavement in the vicinity of the box,

[0145] - connecting the adjacent trees with root paths under the pavement into strips of greenery,

[0146] - connecting the box with root paths under the pavement with the adjacent open area

[0147] (fig. la, lb, 1c). It can be assumed that the optimal substrate volume for trees with a trunk diameter of up to 10 cm, measured at a height of 100 cm, planted in cities is 6 m3. A tree with a trunk diameter of 40 cm, measured at a height of 100 cm, requires a volume of 30 m3of soil. It can be assumed that a small tree requires a box with an area of 17 m2, a medium tree of 28 m2, a large tree of 42 m2. The minimum area of the box for planting trees should be 10 m2. The area of the box per tree can be smaller, provided that the boxes are connected.

[0148] Example 6a. Method for optimizing a tree pit during the construction of a road pavement sub-base using the anti-compression stone-and-soil mix of the invention in case of planting new trees.

[0149] An example relates to obtaining a road pavement sub-base using the anti-compression stone-and-soil mix (PA) of the invention in the case of planting new trees in a paved surface zone with a protective truss covering a box around a tree.

[0150] The top layers within the designed excavation of the pavement are removed, and then an excavation is made to a depth of about 60 cm (depending on the construction variant used) in the zone designed for the development of tree roots under the pavement with the help of an additional manual digging . The bottom of the trench (native soil) is loosened to a depth of 20 cm. The edges of the planted tree box (preferably in the form of a concrete structure limiting the box) are mounted on a 10 cm layer of the PA aeration layer or on the PA aeration layer. At the bottom of the excavation, in 25-30 cm thick layers, crushed stone of the aeration and then vegetation layer is laid, and each of the layers should be compacted four times. The aggregate is compacted before the substrate is washed into it so as to avoid compacting the substrate between the aggregate. The aeration layer is formed in such a way that it is inclined by 1% towards the drain pipes. After laying each of the layers (separately aeration and separately vegetation), by means of a small amount of water, the substrate is washed into the spaces between the aggregate. The substrate is laid in layers with a thickness not exceeding 3 cm until the entire layer of aggregate is fdled, so that there is not too much of it, only enough so that the aggregate is visible on top of each layer. The planting box is partially fdled with horticultural soil, and then a tree is planted. Up to the height specified in the design, subsequent layers of aggregate are laid and the substrate is washed into them according to the above indications in order to avoid compaction of the substrate. After filling the profile with the aeration layer of the anti-compression stone-and-soil mix, an aeration and irrigation chamber is placed directly on it, a vegetative layer of the PA is laid at the level of the side openings of the chamber. The height of the chamber is set and adjusted for irrigation and aeration (one chamber for each planted tree) and the concrete structure limiting the pit with the use of crushed aggregate with a fraction of 2-4 mm, without the use of sand or gravel for this purpose. Preferably, the two laid PA layers are covered with a 125 g / m2geotextile. In the upper part of the profde, a layer of bedding (levelling layer) and pavement is laid according to the given design. The planting box is supplemented with a horticultural substrate and the newly planted tree is secured and stabilized with supports and ties. The surface of the planting box is secured with a protective truss for trees, arranged flush with the pavement (Fig. 2a, Fig. 2b).

[0151] Example 6b. Method for optimizing a tree pit during the construction of a road pavement sub-base using the anti-compression stone-and-soil mix of the invention in the case of improving the habitat conditions of existing trees growing in the vicinity of a paved surface.

[0152] An example relates to obtaining a road pavement sub-base using the anti-compression stone-and- soil mix (PA) of the invention in order to improve the habitat conditions of existing trees growing in the vicinity of a paved surface as a tool for improving habitat condition.

[0153] The top layers within the designed excavation are removed, and then with the help of an excavator and the additional help of manual digging (AirSpade, american forks), the excavation is made to a possible depth around the trunk of the existing tree (the thickness of PA laid shallower than assumed in the design in the event of a collision with the roots of the tree is allowed) and the assumed depth further away in the root zone of the tree. The bottom of the trench (native soil) is loosened to a depth of 20 cm. A possible underground installation in the structural substrate is secured with a 125 g / m2geotextile with gravel fdling of the space between the installation and the geotextile. The height of the chamber is set and adjusted for irrigation and aeration of a single tree and the concrete structure limiting the pit with the use of crushed aggregate with a fraction of 2-4 mm, without the use of sand or gravel for this purpose. At the bottom of the excavation, in 25-30 cm thick layers, crushed stone of the aeration and vegetation layer is laid, and each of the layers is compacted four times. The aggregate is compacted before the substrate is washed into it so as to avoid compacting the substrate between the aggregate. The upper surface of the aeration layer is formed in such a way that it is inclined by 1% towards the drain pipes. Further, by means of a small amount of water, the substrate is washed into the spaces between the aggregate. The substrate is laid in layers with a thickness not exceeding 2 cm until the entire layer of aggregate is fdled, so that the aggregate is visible on top of the layer. After filling the profile with a stone-and-soil layer, directly on it, at the level of the side openings of the chamber, a 20 cm aerating PA vegetation layer is laid, which is then compacted. Up to the height specified in the design, subsequent layers of aggregate are laid and the substrate is washed into them according to the above indications, such that the compaction of the substrate is avoided. After the entire designed stone-and-soil layer has been built, it is checked whether the crushed stone is still visible on top of the layer. The laid layers are covered with a 125 g / m2geotextile. In the upper part of the profile, a layer of bedding (levelling layer) and pavement is laid according to the design. During construction, edges or curbs are installed on concrete footings; if necessary, an edge or curb is installed having a modified shape or placed on a modified concrete footing in order to avoid collision with the existing tree roots. In the absence of roots, culverts (analogous to root paths) are provided to allow the roots to grow between the green belt and the PA zone (fig. 3a, fig. 3b).

[0154] List of numerical references

[0155] 1- open box

[0156] 2- closed box

[0157] 3- green area

[0158] 4- root path

[0159] 5- sub-base using the anti-compression stone-and-soil mix

[0160] 6- box filling

[0161] 7- edge

[0162] 8- aeration and irrigation chamber

Claims

Claims1. An anti -compression stone-and-soil mix, characterized in that it comprises:- a vegetation layer fdled with crushed rock aggregate of the 31.5 / 63 mm fraction, compacted with a soil substrate, and located below this layer,- an aeration-infiltration layer filled with crushed rock aggregate of the 80 / 150 mm fraction, compacted with a soil substrate, wherein the rock aggregate comprises rocks selected from: gabbro, basalt, diabase, diorite, granodiorite, porphyry or a mixture thereof, preferably gabbro, while the soil substrate is a mixture comprising:- compost from leaf soil in an amount of 0.6 to 1.7 parts,- green compost in an amount of 2.4 to 6.3 parts,- rock meal in an amount of 1 part, preferably comprising gabbro, basalt, tuff or mixtures thereof,- loose mineral component in an amount of 10 to 26 parts, wherein the above proportions of the components of the soil substrate are given in the volumetric - bulk - air-dry mass ratio.

2. The anti-compression stone-and-soil mix according to claim 1, characterized in that the loose mineral component is a mixture comprising: clay in an amount not exceeding 5 to 8%, sand in an amount from 57 to 62%, dust in an amount from 32 to 38%, wherein the above contents are given in % by volume of the loose mineral component.

3. The anti -compression stone-and-soil mix according to claim 1 , characterized in that the soil substrate comprises:- compost from leaf soil in the amount of 1 part,- green compost in the amount of 3.8 parts,- gabbro meal in the amount of 1 part,- loose mineral component in the amount of 16 parts.

4. The anti-compression stone-and-soil mix according to claim 1, characterized in that the soil substrate comprises:- compost from leaf soil in the amount of 1.7 part,- green compost in the amount of 6.3 parts,- basalt meal in the amount of 1 part,- loose mineral component in the amount of 26.7 parts.

5. The anti -compression stone-and-soil mix according to claim 1 , characterized in that the soil substrate comprises:- compost from leaf soil in the amount of 0.6 part,- green compost in the amount of 2.4 parts,- tuff in the amount of 1 part,- loose mineral component in the amount of 10 parts.

6. The anti-compression stone-and-soil mix according to claim 1, characterized in that the height of the vegetation layer is at least 20 cm.

7. The anti-compression stone-and-soil mix according to claim 1, characterized in that the height of the aeration-infdtration layer is at least 30 cm, preferably from 30 to 40 cm.

8. The anti -compression stone-and-soil mix according to claim 1, characterized in that it further comprises a structural layer located above the vegetation layer filled with crushed stone aggregate of the 4 / 31.5 fraction, preferably of gabbro or quartzite rock, preferably having height of at least 10 cm.

9. Use of the anti-compression stone-and-soil mix according to any of claims 1-8 for the manufacture of road pavements allowing for the growth of trees, preferably wherein said mix is used for the manufacture of a sub-base.

10. The use of claim 9, characterized in that the sub-base has a retention capacity of 0.17 to 0.31 m3 / m2.

11. A space optimization system for the development of tree roots comprising a planting box arranged in a sub-base characterized in that the sub-base comprises the anti-compression stone- and-soil mix according to any of claims 1-8.

12. The system of claim 11, characterized in that the planting box is provided with openings in the lower part.

13. The system of any of claims 11-12, characterized in that it further comprises a retaining member mounted within the sub-base, preferably provided with a notch.

14. The system of any of claim 13, characterized in that the retaining member is an edge, a curb, or a continuous footing.

15. The system of any one of claims 11-14, characterized in that it further comprises an aeration and irrigation chamber mounted within the sub-base, preferably with an open bottom and perforated sides at the height of the vegetation layer of the sub-base.

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