BE1020376A5 - ORGANO-CONCRETE BOTTOM FOR GRASS FIELDS. - Google Patents

Description

ORGANO-CONCRETE SOIL FOR GRASS FIELDS DOMAIN OF TECHNOLOGY

The invention in question relates to a concrete product intended primarily as soil hardening. The specific goal is to create a pressure-solid soil on which grass growth is possible. Various products are known in this domain in the form of grass troughs, grass-floor reinforcements in plastic, cellular concrete with earthen covering, artificial grass mats, etc. The proposed product makes it possible to make a pressure-fixed grass floor in such a way that no intensive mud formation or erosion occurs during intensive entry and loading. ) occurs.

The major advantage of the product presented here is that it is a ready-to-pour, pourable mass; in contrast to the existing products; all of which require a very intensive manual placement. Here the grass will be the only one of its kind to find roots and nutrients in the mass of the material itself and not in earthed recesses between concrete or plastic grids. The only product of its kind consists of a mixture of concrete and an organic matrix that is produced in one mixture, where other products must first have a concrete structure that is impregnated or covered with an organic growth medium in a second phase. As the only one of its kind, the organic growth medium can be free from cultivation, which in other products is an obstacle to working in one mixture. As the only one of its kind, we can very easily vary the relationships between the organic and inorganic phases, allowing us to change the properties depending on the application. Unlike other products, there is no air or gas cavities in the material so that the compressive strength is not reduced as a result.

Another aspect of this substrate is its growth-limiting properties for the grass sown on it. This allows the number of mowing operations to be greatly reduced.

The product is therefore situated in the domain of erosion, mud-resistant, and growth-limiting grass soil pavements.

Fields of application are numerous: in road construction: as a roadside material in places that are often driven by vehicles.

As grass growth slowing down of cycle paths.

Soil occurring on festival meadows and farms.

- As bank and dyke covering of ponds and watercourses.

TECHNICAL PROBLEM FOR WHICH THE INVENTION OFFERS A SOLUTION.

-Grass verges along public roads, in particular the grass strips between the asphalt and the cycle paths that are on the same level, are very often broken by parking vehicles or vehicles that drive up the road when entering an entrance. As a result, pits and pits are formed in these grass strips, mud formation and the grass disappears. - National cycle paths (eg cycle junction network) are often reduced to half their width in the summer months by high sprouting roadside grass that hangs over the cycle path. This obliges cyclists to cross each other much closer with the increased risk of collisions.

Mowing this high-sprouting roadside grass entails a high maintenance cost for the competent government.

-In farms we see in the transition zone from the meadow to the sheds where the animals enter intensively that strong mud formation occurs.

-Festival meadows with intensive access (open air concerts) disintegrate very quickly in case of rainfall, resulting in mud formation. This initially causes hygienic problems, but also security problems in evacuation circumstances (evacuation ...).

-To improve the erosion resistance of banks and dikes with an aesthetic and ecological hardening.

The proposed invention can adequately provide a solution to the above stated problems and this in an economically viable manner.

As mentioned earlier, this is a ready-to-pour, castable mass that, like a traditional concrete, will cure slowly and which, in contrast to the existing products (grasses, artificial grass), does not require intensive manual placement. The product can be manipulated like a traditional concrete; possibly in a formwork or drag formwork; or with the pavements laterally present (concrete cycle path, asphalt track) as an existing formwork form.

SOLUTION FOR THE PRESENTED PROBLEM

The product presented here allows on the one hand to combine sufficient compressive strength, erosion resistance, tensile strength and crop inhibition of a concrete product with the fertility, water permeability and crop stimulation of soil.

Depending on the desired properties and application, the properties can be varied within certain margins: compressive strength, tensile strength, erosion resistance, fertility, growth inhibition and water permeability.

This can be achieved by varying the organic and inorganic phases of the product within certain margins.

The product therefore consists of an inorganic phase: concrete; and; an organic phase: a carbon, nitrogen and nutrient mineral source.

The inorganic phase, the concrete, will provide the properties of pressure resistance, tensile strength and erosion resistance. The organic phase will ensure the growth and control of grass growth. Essential for the intended properties of the product is the way these organic and inorganic phases relate spatially and volumetrically to each other: we have to create a "petrified sponge" structure where the air cavities of the sponge are filled with the organic phase and the "sponge skeleton" consists of concrete.

In this way, grass roots can slowly penetrate the organic phase during their growth through the concrete phase.

THE ORGANIC PHASE: in principle any concrete type can be selected in function of the desired properties. All possible additives and reinforcements for reinforcement can be used; as far as they do not undesirably disturb the grass growth properties. Water-permeable concrete will usually be preferred (see standard specification 250).

THE ORGANIC PHASE: the organic material consists mainly of carbon compounds that also contain hydrogen. In practice, the organic material is composed of at least carbon (C) and hydrogen (H), often also oxygen (O). In addition, other elements occur: nitrogen (N), phosphorus (P) and sulfur (S).

Since we are inspired by natural grass growth in natural soils for optimum grass growth on our material, the organic matter content will be at least as high and given the growth-inhibiting properties of the concrete, it will be quite higher.

For example: - natural pastures on clay soil contain 9.7% organic matter on sandy soil contain 6.2% organic matter on loam soil contain 6.0% organic matter - potting soil contains 20 to 30% organic matter

Organic matter in general consists of many thousands of different complex organic compounds. Carbon (C) is the most important component. It is assumed that the organic matter in the soil contains on average 58% carbon.

Organic matter in natural soils is the organic material that has been broken down and transformed to the point where the origin has become unrecognizable: this is called humus (from plant debris, litter, leaves, animal waste products, manure ...). In natural soils, humus binds to the clay particles so that they stick together to form crumbs or aggregates that together form the clay-humus complex. Both the humus and the clay particles in the soil are negatively charged so that the clay-humus complex can retain positively charged elements (H +, K +, Na +, Mg +, Ca +). The capacity of a soil to retain positively charged elements is called the cation exchange capacity (CEC).

In the synthetic soil material proposed here, we must reproduce these properties. We will substitute the inorganic clay, loam or sand phase in the natural soil with a pressure-fixed concrete structure.

To provide sufficient water permeability and penetration for grass roots, we have to make a "hardened sponge" structure: gaps in the concrete structure are filled with organic material. With this we create macropores which will provide both water and root infiltration.

In order to achieve this structure, we must ensure that when the organic phase is mixed in, the latter does not pulverize and would be completely homogeneously mixed into the concrete mixture as a fine grain. The organic mixture that we must use must therefore have a certain firmness and structural stability. Furthermore, the organic phase must be composed in such a way that nutrients are supplied to the grass roots directly, as well as in the medium and longer term.

Various organic mixtures were found experimentally, but the presence of charcoal and fertilizer-impregnated, water-saturated wood shavings was always required. Furthermore, optional additions are: straw, shredded tree bark, wood or plant remains, potting soil or compressed potting compost grains, manure of animal origin. Charcoal is crushed and sieved at a fraction of 0 to 10 mm with linear grain distribution. It is an important carbon source for plant growth, is inert and is degraded very slowly, ensuring C in the long term. It retains its dimensions during blending so that it provides the macroscopic cellular structure. It increases the water permeability and water retention of the soil; it also has filtering properties. Charcoal is added for approximately 10% of the total weight.

Wood shavings impregnated with fertilizers and water-saturated (wood shavings) is also an important carbon and other nutrient source for grass growth. It retains its filamentous form during mixing and thus provides nutrient channels between the charcoal fragments. These wood shavings come from horse stables or can be produced by adding liquid fertilizers to dry wood shavings from the wood industry. It is also added for approximately 10% of the total weight. These wood shavings can be partially replaced by finely chopped and fertilized straw or highly organic pressed potting pellets. About 5% of the organo-concrete consists of natural animal manure, preferably horse manure that contains a high carbon and nutrient content per unit weight, but all other natural manure can be used. In a first stage, the organic components are mixed dry, after which the prepared concrete mixture is added in a second stage with the addition of the necessary water to obtain a homogeneous castable mass. The standard weight ratio between the organic phase and the concrete phase is 25/75; this means on LOOKg soil material there is 75 kg of concrete and 25 kg of organic mixture. This yields a product with considerable compressive strength (penetration resistance + / _ 5 MPa) with the possibility of spontaneous germination after sowing. The material is processed in its plastic phase like a traditional concrete: it is cast in a formwork with a thickness adapted to the required load. For most applications this will vary between 50 and 150 mm.

All known concrete reinforcements can be used if desired to obtain even better properties.

Higher penetration resistance can be achieved by increasing the inorganic concrete phase as a percentage of the organic phase. This therefore provides a harder, stronger soil layer in which spontaneous grass germination becomes increasingly difficult as the organic phase becomes relatively smaller (<25% to at least 5%).

If we still want to achieve higher compressive strength and penetration resistance (> 10 MPa), we will have to increase the concrete phase to a maximum of 95%. Spontaneous germination of the sown grass can then no longer occur in such soil.

It was found experimentally that when a thin top layer of 1 to 2 cm of soil was laid on the surface of the organo-concrete mixture and then the grass roots growing after germination penetrated into the more inorganic soil layer.

In order to create sufficient penetration resistance on the surface of the organo-concrete mixture, we will make indentations in the newly poured, not yet cured, soil material (for example with the help of a rollprint provided with nail tips). These indentations (impressions) are box-shaped indentations of 1 to 2 cm deep, diameter 5 to 10 mm, with a mutual distance of 0.5 to 2 cm grid-shaped, distributed over the surface. After hardening, the soil is applied to this perforated top layer in a thin layer of 1 a2 cm and lightly rolled.

The grass can then be sown. The grass can therefore germinate in natural conditions and make an initial root formation. When the grass roots have a length of 1 a2 cm they come into contact with the harder organo-concrete, in which they will penetrate and eventually grow into it. We can then establish that the grass growth is delayed the higher the inorganic fraction. In a higher concrete-containing mixture, much slower root growth will occur due to the lower nutrient content and the increased penetration resistance. Where a natural soil with organic matter content of 6% (meadow on loam soil) has a grass growth of up to 30 cm / month (depending on temperature and humidity), with a standard composition of the organo-concrete this will be reduced to around 5 cm / month . This offers the possibility of realizing maintenance-friendly and yet firm features.

It was found experimentally that during dry periods the grass holds just as well to better on organo-concrete soils than on natural soils, thanks to the good water retention of the capillary structure.

Claims (3)

1. Characteristic is the presence in the concrete of charcoal (2), particles with dimensions from 0 to 15 mm. 2. Characteristic is the presence in the concrete of water-saturated wood shavings (3) impregnated with fertilizers. This wood shavings (0.5 to 2 mm thick, 10 to 30 mm long, irregular slices of wood from industrial woodworking) are impregnated with animal fertilizers and urine, either by using it in animal stables, or by mixing it with, and allowing , water dissolved animal manure. 3. Characteristics are the indentations (4) provided on the surface of the organo-concrete which do not perforate the mass of the material. In order to obtain faster grass germination in the organo-concrete, indentations (impressions or impressions) are made on its surface in the form of needle, nail, pyramid, cylinder, sphere, cube, beam, or otherwise formed cavities. Characteristic of these indentations is that they do not perforate the mass of the organo-concrete, so that the organo-concrete also runs under the cavities. Potting soil or soil is applied to these cavities. The grass seed applied to it can then germinate under optimum conditions, after which the roots can penetrate further into the underlying organo-concrete.