DE2406968A1 - Portland cement/org fibre/fertilizer mixes - growing medium for the recovery and stabilisation of soils - Google Patents

Abstract

Mixtures based on an inorganic binder, Portland cement, a fibrous organic material, e.g. peat, bark, leaves straw, cellulosic fibres, ground wood knots, paper paste etc, and a fertilizer e.g. NPK, urea, nitrate or manure are used to provide a cheap growing medium for the recovery and stabilisation of waste land resulting from civil engineering work, volcanic eruptions etc. The cement: organic fibre: fertilizer varies according to application but typically is 5-100: 5-40: 1-20. The mixture is applied as an aqueous mix and typically 50-1000 gms. of cement is used to cover 1m2 of land. Seeds can be incorporated into the mix.

Description

Growth medium for covering soil surfaces. The invention relates to a growth medium to be used for soil or soil surfaces that are threatened by erosion and hostile to vegetation, where one can with the normal Methods of sowing a satisfactory vegetation cannot achieve, too cover and at the same time bind the earth. The growth medium according to the invention includes a dry mix of components that, after adding water directly on the surface of the soil by means of an apezial device called a hydraulic seeder (hydro seeder), recently used for sowing large areas of land without Vegetation has been developed. After spraying, the growth medium will settle and forms a relatively thin coating that binds the soil underneath, the seed holds and protects and also the necessary moisture and nutrients for germination and initial growth until the roots are long enough to penetrate the ground below and hold it tight, The need growth media of this type has recently increased significantly and engineering activities in the construction of roads, airfields, dams, Dykes etc. have extensive and ugly changes in the natural environment Episode, in which huge road embankments, rock dumps (rock tips), earthfills etc., which cannot be sown in the usual way and therefore remain as ugly spots in the landscape.

The lack of vegetation leads to serious disadvantages: When it is dry Weather can affect the road safety, and in the case of dust generation Heavy rains can cause damage to water currents. Apart from the practical ones Disadvantages, it is also necessary for aesthetic and environmental reasons Take precautions to cover these areas with vegetation as soon as possible.

Growth media for this purpose are already known, but all have certain flaws and disadvantages and do not meet the most important requirements that you put in front of them. A number of different organic binders are known or adhesives either alone or in admixture with fiber-forming organic Humus materials such as cellulose fibers, crushed peat, leaves, straw etc., to use. However, it has been difficult to locate materials which combine in a satisfactory manner with the floor surface below, and, if they were used together with the usual fertilizers on the market, an undesired precipitation occurred which posed major problems. Adhesives that it is known that this does not cause problems, but its high price prohibits it their application.

Examples of known binders that have been used include Tall oil or pine oil made by Esskron AB, Sweden under the trade name "Essbinder" is brought onto the market.

It is also known to form a binder from asphalt emulsion either alone or together with finely chopped straw or leaves to manufacture. Seeds and fertilizers can be added both to the dry mix and to the mix after it has been mixed with water. The aqueous mixture is then sprayed onto the ground by means of a hydraulic seeder (Gartnerwält 56 (1956), 141).

Recently it has been proposed to use ordinary mortar as a binder (plaster), where it is claimed that eiii have a milder, more neutral effect Mortar made of calcium sulphate has a positive influence on the germination capacity and growth of the seed has. The mortar is then combined with a non-hardening filler, such as powdery, dead-burned plaster of paris, and plaster of paris.

It can also use small amounts of additives that absorb water and are able to hold, as well as nutrients are also used.

However, research has shown that such substances only have a low binding effect. One must therefore when there is a risk of soil erosion consists of fibrous, reinforcing materials, such as fiberglass braiding, diS the soil surface is laid, etc. prior to the application of the aqueous seed mud use.

It is also known from Norwegian patent specification 87 342, to stabilize the soil by placing a cement composition in it a small amount of pentachlorophenol and chlorinated cresylic acid and a powdery one Herbal substance a2Ls filler mixes in.

However, this is not a growth medium, it is about the application of a soil stabilization material that leads to a completely different one Purpose, namely on road surfaces, taxiways, etc., is to be used, where germination and growth should preferably be avoided.

The following main requirements should be placed on a satisfactory growth medium be put: 1) It should be the basis for the existence of a certain type of vegetation form.

2) It should have the property of adhering to sand, gravel, etc.

3) It should be able to set or harden.

4) It should have the ability to absorb and hold water.

5) It is said to work with a hydraulic seeder without it to clog.

6) It's supposed to be cheap.

None of the previously known growth media corresponds to all of these properties. There are specific issues related to the ability to hit the ground underneath to bind, and occurred regarding the price.

It has now been found that powerful, inorganic mineral binders Cement-based works just as well as a means of binding and setting in egg growth medium suitable. Binders of this type are extremely alkaline, so that they are immediately accepted became that they must prevent the seed from germinating and growing. Surprisingly it has been found that the germinating capacity of the seed is not damaged and that the hardened material is also able to absorb water and food and hold. Among the trusses of this type that have been studied so far, Ordinary Portland cement has proven to be particularly suitable because it results in a hardened material that bonds very well to the ground below, very resistant to water and heavy rainfall and at the same time is very economical to use.

of the invention The growth medium / contains or consists of a Mixture of cement, organic fiber material and fertilizer. As a fiber component can be crushed peat, bark, leaves, straw, cellulose fibers, cellulose coarse material or knot portion (knotter pulp), a by-product of the cellulose or pulp industry, be used. The pulp coarse or

-The knot portion is dried to a loose, short-fiber mass torn those with dry cement and fertilizers and also with seeds if necessary - is mixed. sls fertilizers can contain all types of commercial fertilizers, e.g. NPE-The, Urea or nitrate. There can also be natural fertilizers in the form be used by dry fertilizers.

The dry mix does not spoil during storage. Before use it is mixed with water in a hydro seeder and then sprayed on the ground. If the seed is not added earlier, it can be added to the growth medium be added when mixing with water. But it can also be used separately on the Soil are applied. The relationship between base material and binder is not important. With compositions of about 75 to about 60 percent by weight cement and from about 25 to about 40 weight percent dry pulp pulp satisfactory results have been obtained. So is the crowd Water that needs to be added is not important. However, it has the best results one with a mixture of about 1 part by weight of growth medium to about lo parts by weight Get water.

This gives a composition that works particularly well with a hydraulic seeder can be sprayed directly on.

Example 1 The following example shows that the combination of pulp-coarse or -not fraction and cement is very well suited to washing out the soil, on which this composition is sprayed to prevent.

20 g dry, finely torn cellulose pulp or knots, 30 g portland cement, 15.6 g chlorine-free NPE fertilizer and 820 cc water well mixed together. An aluminum trough 0.13 m2 and 2.5 cm deep was used filled with ordinary sand covered with this mixture. The fat, flowing mixture became evenly with a special distribution device sprayed on the sand. The coating was left at normal room temperature for 24 hours to sit down. The trough was then placed under a container at an angle of 300 at a distance of 22 cm. The container had a number of openings in the ground, through which a steady stream of heavy "rain" (about 2 1 / min) to the test ffel. After 2 hours there was the surface and the sand underneath unchanged.

Example 2 Example 1 was repeated with the exception that in addition to the pulp coarse or pulp content cement, fertilizers and Water 3.25 g grass seeds were added.

This mixture was treated in the manner described above.

The subsequent rain treatment showed the same good result. the The surface and the sand below were unchanged.

Example 3 A growth test was carried out in the following manner: 154 g dry, finely torn cellulose pulp or

Lump portion, 346 g portland cement, 154 g NPK fertilizer, 15 g ryegrass seeds (Lolium temulentum) and 6 liters of water were mixed together and evenly sprayed on 1 m2 of floor. 15 g of ryegrass were used in the usual way without the addition of Sown pulp coarse or lump portion and cement. The two amounts of grass when compared, showed that they are in no particular way one another differentiated.

Example 4 Example 1 was repeated, but with the difference that instead of pulp coarse material or pulp portion, a mass of finely torn Paper used. The surface layer had the same good properties as they have been described in Example 1.

Example 5 After the Vestmannaeyåar eruption in Iceland in 1973 was most of the area covered with a thick layer of lava and volcanic ash covered. In order to make the island habitable again, it had to be Stabilize the ash layer. Soon large areas were sown and fertilized. The planting however, of grass in this mobile ash was very difficult, and the largest Part of the job was in vain.

Then experiments were carried out with a mixture of 350 g pulp coarse or -Enotes, 66 kg cement, 33 kg IPK-I) Unger and 15 kg grass seeds, which with Water mixed and with the help of a HydrosE machine on the ashes in an area of nearly 1/4 acre (looo m2) was sprayed on. After 2 weeks there was a good ground for growth laid on a stable, underlying surface. To ? Month was the stabilization of the ash layer by the grass and its roots pretty far advanced.

The ratio of fiber material and cement can be varied widely. The amount of cement depends on the character of the material underneath, that should be protected. The same applies to the amount of fiber material. Usually about 20 to about 200 g / m2 are used. On loose sand and in exposed places, e.g. steep slopes, almost 150 g / m fiber material should be used1 to form a good enough cover. The amount of cement, however, can range from about 50 to about looo g / m2 vary. However, it should preferably be between about 200 and about 400 g / m2. It is appropriate to use about 10 to about 100 g / m2 of fertilizer, preferably 20 to 40 g / m² to be used. Suitable weight ratios between cement / fiber material / fertilizer depend, as already mentioned, on the type of terrain and the surface of the ground. Usually it can be 5 to 10/5 to 40/1 to 20, preferably 10 to 40/5 to 20 / 5-15. Usually a weight ratio close to 2: 1: 1 is used.

Claims (4)

Claims 1) Growing medium for covering soil surfaces, labeled by a mixture of inorganic mineral binders based on cement, a organic fiber material and detergent. 2) growth medium according to claim 1, characterized in that it contains ordinary portland cement as a binder. 3) growth medium according to claim 1 or 2, characterized in that that it is the organic fiber material pulp coarse or note content (knotter-pulp) contains. 4) growth medium according to claims 1, 2 or 3, characterized in that that it contains seeds as an additional component.