FI96765C - Method for preparing a hydrophobic aggregate-like peat granule and use of such a peat granule as a concrete aggregate - Google Patents

Description

96765

Process for the preparation of a hydrophobic aggregate peat granule and the use of such a peat granule as a concrete aggregate

The invention relates to a method for producing a hydrophobic aggregate peat granule according to the preamble of claim 1 and to the use of such a peat granule as a concrete aggregate.

10 For decades, attempts have been made in concrete technology to find ways to improve the thermal insulation capacity of concrete and at the same time reduce its bulk density. For this purpose, e.g. straw, the so-called Leca gravel and concrete and 15 wood chips are made of so-called Porous concrete. The use of blast furnace slag as a concrete aggregate is also known. Ma-mouth slag is a coal combustion waste generated in the manufacture of steel. It does not contain air, so its thermal insulation capacity is poor.

• 20 Leca gravel refers to porous clay granules that are; : burned to enclose the air inside it. Leca gravel is ·· hard but easily broken. Due to its fragility and uniformity, it does not function satisfactorily as a concrete aggregate.

• · · • · «25 Siporex is made by heating at a high temperature • ·« *. ‘Concrete mass to which wood chips have been added. When heated, water evaporates from the wood chips and the wood chars or burns, resulting in: **: gas-filled cavities are formed in the pulp. Siporex is a lighter Building Material and has a relatively good thermal insulation capacity.

The object of the invention is to provide a material from peat which can replace heavy aggregate, for example in concrete grades, where lightness and very good thermal insulation are required of concrete. The process according to the invention for producing a hydrophobic aggregate-like peat grain is characterized by what is stated in the characterizing part of claim 1.

By using at least in part such a hydrophobic aggregate-like peat granule as the aggregate of the concrete mixture, the thermal insulation capacity of the concrete is considerably improved and its bulk density is reduced. Such a aggregate also guarantees sufficient compressive strength for the concrete.

Peat, which is a fossil material, can be compressed and dried to produce a product that is light, heat-insulating, water-repellent and hard enough to be used in the manufacture of concrete for load-bearing structures as well. The strength of the product is based on aggregate particles bound to the peat pores. In a concrete mix, the product behaves like crushed rock.

:: The lightness and good thermal insulation of the product are again based on: 20 the fact that it contains peat particles encapsulated; sufficient amount of air. The air is encapsulated: in the peat down to the smallest peat particle. Compressed and dried peat repels water, ie it is a hydrophobic substance. For the sake of clarity, it should be mentioned that milled peat and 25 ns. peat cakes absorb water into their pores. This is because. different treatment of peat.

• · · * · · • · I! · · • · · * ·] 1 The peat peat solids consist of fossil and rotting plant parts and microscopically small aggregates. Natural peat contains a considerable amount of water and air bound to it by decaying plant parts. When the peat mass is compressed, water is removed and a moist, water-mixed, adhesive binder containing hardening and binding aggregate particles encloses 96765 3 of each peat particle, leaving air inside the peat particle. This adhesive binder acts like a concrete adhesive, i.e. a curable binder. When the peat is dried after pressing, it hardens into a body with high compressive strength, 5 as if it were petrified into an air-containing fossil structure.

The aggregate of the concrete mix according to the invention is prepared as follows. The peat is lifted from the peat field using a peat lifting device known per se, for example using a rotary-blade peat milling machine. The moist peat mass is transported to the mill and placed in a peat receiving silo. From the receiving silo, the peat mass is conveyed by a conveyor to a mixer, which is, for example, a screw mixer. If necessary, water and / or a binder, for example lime or peat ash, are added to the peat mass in the mixer. The mass is therefore mixed until homogeneous. The monitoring equipment in the mixer preferably continuously analyzes the water content and the amount of binder. The mixed peat mass is fed to the press. The press is preferably a hydraulic press. Pressed through the nozzles of the press ’. A matless or rod-like, preferably continuous • peat web is conveyed to the drying oven by means of a conveyor.

; The drying oven is preferably continuous. Drying oven- •! ' sa peat mass is heated to dry it and dry · * · *; 25 which is monitored by means of monitoring devices. As a result of pressing and drying, the peat hardens. Drying. . ·. then the peat web is passed to the crusher and • · · crushed into pieces. After crushing, the hot silicon • · · peat is conveyed to a cooling and storage heap by a conveyor for cooling. In the cooling and storage heap • · ·: .., i peat pieces are allowed to cool for about two days. As they cool, they continue to harden.

After cooling, the peat bodies are crushed with a crusher of the hammer, jaw or spindle type, for example, into peat granules of suitable size for the production of peat concrete. The peat granules are screened in the screening equipment into components of different sizes, i.e. fractions. The sieve fractions are proportioned using a concrete technique and mixed with a reactive binder such as cement, lime or gypsum and water to form a peat concrete mass. The binder can also be a mixture of the above and other binders. The aggregate can be either partially or completely replaced by crushed peat.

10 As it dries, the peat concrete mass becomes peat concrete. Proportioning means that a certain number of sieve fractions are taken to provide a suitable size distribution for the concrete mix aggregate. Depending on the application, the size distribution is different for different concrete mixes.

15 Crushed peat produced as described above meets the quality requirements for concrete aggregates. Peat is a water-repellent, hydrophobic substance, it contains air bound to itself. Crushed peat behaves like aggregate in concrete mass. As peat is considerably: 20 0 lighter than aggregate, the use of peat I as aggregate provides a considerable advantage. The volume weight of the finished peat concrete I varies by about 1100 kg / m3. . . about 250: kg / m3. Peat concrete insulates heat well. It is also an easy-to-work material. The peat bean according to the invention is very suitable for damping a wide variety of products. It can also be made into an injectable. mass.

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The invention is not limited to the embodiment described above, but may be modified within the limits defined by the appended claims. In some cases, the invention may also be modified by known methods. hydrophobic peat produced in the bog by crushing into peat granules for the production of concrete.

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Claims (5)

A process for producing hydrophobic aggregate peat granular peat granules, characterized in that the peat mass is pressed through a nozzle or the like to mobilize the microscopic aggregate particles in the peat so that they pass to the surface of the peat particles in the pulp. heat drying and crushed into granules of suitable size. Process according to Claim 1, characterized in that, before crushing, the pulp is stirred to homogenize. 3. A process according to claim 2, characterized in that, in connection with the stirring, the peat mass and / or binder are added, such as, for example, lime and / or peatwash. 4. Use of the hydrophobic aggregate-like peat granulate prepared by the process according to any of the preceding claims as concrete material in concrete. Use according to claim 4, characterized in that they; The hydrophobic aggregate-like peat granules are screened in and 1 »· · · 1; known in the known manner and that the sieve fractions were proportioned by something known per se in the field of concrete technology to be used as frame material in concrete for a particular purpose of use. i1 · · «IM« · ·· • tl i: IM I!