NL1002917C1 - Production of construction material from broken rubble - uses moist rubble containing hydrated cement - Google Patents

Abstract

Hydro-thermally hardened construction materials are produced consisting of moist rubble containing hydrated cement. Pref. the rubble consists mainly of broken concrete, with a particle size of 0-2 mm. The rubble is mixed with sand and slaked lime may be added. The shapes may be brick, block or structural.

Description

Method of construction material to be produced thermally and thermally, with the reuse of construction rubble.

The raw material for the building material is the product obtained when the building pulp is broken, which consists of pieces of concrete and / or pieces of masonry stone, mixed with masonry mortar.

The particle size of the rubble is preferably chosen between 0 and 2 mm, but the construction of the building material can also be done with coarser raw material.

The building material is obtained by mixing the rubble with water and compacting the mixture into a desired shape, after which it is cured in a steam pressure vessel.

In experiments, the best results were obtained with rubble parts mainly consisting of concrete rubble from 0 to 2 mm. The hardening of compacted material under steam pressure is known. In the known technique, sand is mixed with slaked lime and water.

Characteristic of the invention is that already hardened cement, which occurs in the crushing rubble in the car hole, is converted into usable binder and that a building material of usable strength is obtained.

In order to obtain good strength, it is necessary that the new binder obtained under steam pressure has sufficient silica available to form optimum binder.

This means that in some cases sand will have to be mixed.

In order to achieve optimum results, it is important to process the debris immediately after crushing into hydro-hardenable product 30 or to ensure that no moisture can enter the debris.

Concrete rubble does not yet contain water-reacted cement and lime, which reacts under humid conditions with carbon dioxide from the air to form carbonate, which cannot react as a binder under hydro-thermal conditions.

The fact that the other substance, the cement residue, converts on contact with water into a cement hydrate is not important for chemism, whereby 1002917 strong binder is formed in the autoclave.

It is further known that building materials can be manufactured from sand and cement under hydro-thermal conditions, and it is also known that combinations of cement and lime are used as a binder for making building material, such as, for example, in the production of aerated concrete.

However, these known techniques never start from already hardened mortar residues.

Hardened mortar is an agglomerate of silica-containing particles, sand and / or gravel particles, which are encapsulated in hydrated cement.

Reactions between hardened mortar calcium hydroxide, the main constituent of lime, with hardened cement-encapsulated reactant, sand or gravel, are not obvious.

To produce building material, the crushed rubble can also be mixed with slaked lime and sand.

The building material can be manufactured in stone, block or element form.

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Example 1.

Broken concrete rubble, the particle size of which ranges from 0 to 2 mm., Is mixed with water and compacted in a mold under a pressure of 300 kg. per square centimeter.

After the mass has been compacted, for example to a brick size, the mass is pressed out of the mold and taken out of the press installation to be put in an autoclave, in which hardening is carried out under steam pressure.

10 After a hardening time of 8 hours, the stone is ready for use as a building material.

Example 2.

Broken concrete rubble mixed with brick rubble is processed into building block in the same manner as indicated in example 1.

Example 3.

In the mixture of concrete rubble and water, brick rubble in the granulate size becomes 2 to 8 mm. included.

This brick rubble is intended here as a filler and has a much smaller function as a pozzolanic substance than in mixture 2.

Applying pieces larger than 2 mm. does not cause difficulties when milling conduit slots in walls made with the building blocks obtained from this mixture.

Example 4.

30 Sand is added to a mixture of rubble and water.

After processing, in the manner described in example 1, the mixture also gives up a useful building material.

Example 5.

As described in example 1, but with rubble, the granulate composition of which ranges between 0 and 4 mm.

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Example 6.

Slaked commercial lime is added to a mixture described as in one of the examples.

5 The product obtained here can also be used as building material.

Example 7.

Dye is added to a mixture described as in one of the examples.

As a product, a decorative product which can be used as a color stone is obtained.

Example 8.

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Debris with a granulate build-up between 0 and 32 mm. Is mixed with water and poured into a mold.

Mold with contents is autoclaved under steam pressure.

After demoulding, a chunk of building material that is applicable is obtained.

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Claims (7)

A method for making hydro-thermally hardened building material, characterized in that the curable material is moist building rubble, in which hydrated cement occurs. Method according to claim 1, characterized in that the construction rubble mainly consists of broken concrete. Method according to the above claims, characterized in that the particle size of the construction rubble ranges from 0 to 2 mm. Method according to one or more of the above claims, characterized in that the crushed rubble is mixed with sand. A method according to any one of the preceding claims, characterized in that slaked lime is added to the mixture. 20 Method according to one or more of the preceding claims, characterized in that the building material is manufactured in brick, block or element form. 1. C 9 i 7