DD244545B5 - METHOD FOR THE PRODUCTION OF CONCRETE MASS FROM ABPRODUCTS - Google Patents

Description

Field of application of the invention

The invention relates to a process for the production of concrete from waste products, industrial slurries and fly ash from coal-fired heating and thermal power plants are used.

Characteristic of the known technical solutions

When using filter bags (FA) for a building material use one must distinguish two main directions of application.

1. Use of the filter ash as an additive

2. Use of the filter ash as a binder.

A combination of both directions of application is possible.

A process is known for recycling fiiter ash as a binder, wherein a sulphatic excitation of the filter ash with anhydrite is carried out and this building material is used for the production of filling compounds (DD-PS 104600).

Hard-to-use wet and filter ashes can be used for civil engineering purposes by adding gypsum and / or cement in a certain ratio to the ash and first processing the ashes into granulated pellets in granulation equipment and grinding them. (DD-PS 48156)

The production of ash granules and use as an additive or binder is known from other patents (DD-PS 35222,223699).

From filter ash can be produced in a known manner porous blocks by adding a foaming agent, beaten the concrete, molded and the molding is brought by air hardening for setting (DE-OS 841728).

Also known is a method for filling and sealing surface storage sites with waste from power plants.

Here, an ash suspension is passed to the storage place by means of pipelines and admixed known binders (DD-PS 201816).

All listed methods for the use of fly ash for the production of building materials adhere to technical and economic deficiencies, which were detrimental to a recovery of these ashes in an economically significant extent.

Although additional grinding of the ashes in many cases leads to an improvement in the strength properties, but in most cases drifting and decay phenomena of the materials produced using ground ashes can not be eliminated.

Similarly, in many cases, the proposed methods can not achieve complete hydration of the active portion contained in the ashes.

But that the binder properties of these ashes are greatly reduced.

As a further disadvantage of known methods of not inconsiderable expenditure on equipment must be mentioned.

Generally, the known methods lack the fact that the quality characteristics of known constructions and structures, which can also be secured with other binders, are aimed at by partial substitution of additives and proportionate binders. The focus of these procedures is therefore always the substitution effect and not the achievement of new quality features and the development of new applications.

Also known is a method for dewatering of binder-water mixtures, wherein the dewatering during a dissolution phase of binder minerals without crystallization takes place, which is determined by chemical analysis or by physical methods (DD-PS 227694).

This method is directed to determining the best time to dewater binder-water mixtures.

This is to prevent the "bleeding" of the concrete by draining excess binder agent.

Dewatering occurs by aspiration prior to the hydration phase of the binder.

Object of the invention

The aim of the invention is to use difficult-to-use waste products on a large scale and effectively economically.

Explanation of the essence of the invention

The invention has for its object to develop a process for the production of concrete from waste products, wherein the effects of cement-damaging components of the waste products are prevented by the use of a resistant binder.

This is inventively achieved in that industrial sludges with a water-solid ratio> 1.3 a strongly water-binding, the hardening influencing substance in amounts of 20 to 60Ma .-%, based on the resulting mixture, is added.

Ausführungsbelspiel

Based on embodiments, the invention is explained below.

example 1

The following formula is used for the production of concrete for base courses in road construction and other lean concrete (per m ^{3 of} fresh concrete):

830kg abrasive slurry (water / dry matter = 1.7 / 1) + 923kg active cohesive fly ash + intensive mixing process

= homogeneous fine-structured concrete very stiff This results in a concrete BK5-12.5 with high bending tensile strength.

Example 2

For the preparation of refurbishment compounds for large-sized concrete products, the following formula is used (per m ^{3 of} fresh concrete):

800kg residue separator slurry from construction industry (water / dry matter = 1.8 / 1) + 400kg less active low-binder fly ash + 120kg Portland cement PZ4 / 45 + intensive mixing process

= homogeneous, spreadable mass

The hardened mass corresponds to a concrete of the strength class BK20.

Industrial sludges with a water-solid ratio> 1.3, a high water-binding capacity and poor dryness are used.

By intensive mixing of active dry ash with its own hardening ability, which had no contact with water, the industrial sludges are dewatered.

The resulting concrete mass can then be compacted, pressed or otherwise solidified, the high water-binding capacity of the industrial slurries having a favorable effect on the complete dewatering reactions.

If necessary, the concrete mass can be combined with conventional aggregates taking into account known effects.

If there are no significant cement-damaging constituents in the industrial sludges, cement can be added after extensive water binding through the ash.

The concrete mass can be used as lean concrete for base courses, for road rehabilitation work, structures, traffic areas in general, high-grade concrete products and thermal insulation, mortar and screed work in a cone-shaped consistency with low "tendency to burn" and high user safety.

Advantages of the invention

- Hitherto unrecoverable, highly water-binding and difficultly dewaterable industrial sludges with cement hardening can be widely used for negatively influencing pollutants.

- Active dry ash, which can be used for conventional concretes only safely on the suspension phase, can be used easily and also on a large scale.

- The unfavorable water-solids ratio of the resulting industrial sludge would require the use of conventional binders unreasonable amounts to achieve for hardening reasonably favorable water-cement values.

- According to the mixing intensity and the Trockenaschezumischungsmenge all consistencies of plastic to stiff are achievable.

- There are many adhesive bridges available due to the large amount of fine components, which results in a high bending tensile strength.

- The hardening takes place without shrinkage.

- The concrete mass has due to the high microposity despite high density good thermal insulation.

- The concrete mass has a high adhesion and is therefore particularly well suited for remedial measures.

- The ratio of DruckVBiegezugfestigkeit is 5: 1 and thus very favorable for finely divided concrete goods and traffic areas.

- The concrete mass is verpreßbar.

Claims (4)

Claim: 1. A process for the production of concrete masses from waste products, characterized in that industrial sludges having a water-solid ratio> 1.3, a strongly water-binding, the hardening influencing substance in amounts of 20 to 60Ma .-%, based on the decisive mixture, is added. 2. The method according to claim 1, characterized in that are used as sludge abrasive slurry and other concrete and binder slurry of the construction industry, red mud, residues from the wet flue gas desulfurization, Schlicke, etc. 3. The method according to claim!, Characterized in that is used as a strong water-binding, the hardening influencing substance active dry ash with its own hardening ability and optionally cement. 4. The method according to claim 1 to 3, characterized in that the mixture is mixed with additives.