Sealing wall building material and method for producing a sealing wall building material

Abstract

The invention relates to a sealing wall building material, which has a binding agent with cement and aggregates. It is provided according to the invention that the binding agent comprises a mixture of cement and fly ash, wherein it is free of clay material, and that it has an impermeability with a kf value of 10.sup.−7 m/s and less.

Claims

1. A sealing wall element formed of a sealing wall building material which has a binding agent with cement and aggregates, the sealing wall element comprising sand with an aggregate 0/2 with a weight proportion of 400 to 1,000 kg/m.sup.3 and a coarse grit with an aggregate 2/8 with a weight proportion of 400 to 800 kg/m.sup.3 and wherein a content of binding agent of at least 400 kg/m.sup.3 is provided, wherein the binding agent comprises a mixture of cement and fly ash, wherein the binding agent is free of clay material, the sealing wall building material has an impermeability measured according to DIN 18130-01 with a kf value of 10.sup.−7 m/s or less when the sealing wall building material is cured, and the binding agent has a ratio of cement to fly ash of between 7% and 60%.

2. A sealing wall element according to claim 1, further comprising: a binding agent having a content of cement of 100 kg/m.sup.3 and a content of fly ash of 300 to 350 kg/m.sup.3.

3. A sealing wall element according to claim 1, further comprising: a flow agent and/or a retarder.

4. A sealing wall element according to claim 1, wherein a fresh mass of the sealing wall building material has a bulk density of between 2.0 g/cm.sup.3 and 2.4 g/cm.sup.3.

5. A sealing wall element according to claim 1, wherein a monoaxial compressive strength q.sub.u of q.sub.u≥500 kN/m.sup.2 is provided at an age of 7 days and of 1000 kN≤q.sub.u≤5000 kN/m.sup.2 at an age of 28 days.

6. A sealing wall with a sealing wall element according to claim 1.

7. A method for manufacturing a sealing wall element according to claim 1, wherein binding agent with cement and aggregates with the addition of water are mixed in a single mixer to form the sealing wall building material for the sealing wall element.

Description

(1) The object is achieved according to the invention by a sealing wall building material with the features of claim 1 on the one hand and by a method with the features of claim 9 on the other. Preferred embodiments are indicated in the dependent claims.

(2) The sealing wall building material according to the invention is characterized in that the binding agent comprises a mixture of cement and fly ash, wherein it is free of clay mineral, and has an impermeability with a kf value of 10.sup.−7 m/s and less.

(3) One aspect of the invention consists in omitting a swellable or preswollen clay mineral, which can only be processed with difficulty, in the production of the binding agent and in providing a mixture of cement and fly ash for the binding agent. The binding agent and the mass are adjusted here as a whole such that an impermeability with a kf value of 10.sup.−7 m/s and less is provided.

(4) The invention is based on the realization that for a sealing wall mass with a good sealing property, the use of clay mineral is not imperative, but this can be replaced by fly ash according to the invention. Fly ash is the solid, dispersible (particulate or powdered) residue of combustion, which due to its high dispersity is discharged with the flue gases. The particle size ranges in this case from roughly 1 μm to 1 mm. Fly ash occurs in large quantities in combustion power plants or in waste incinerators, wherein the fly ash is separated from the flue gases by suitable filter installations. Fly ash is thus suitable with its dispersity for increasing the sealing effect and is also available in sufficient quantities at low cost.

(5) A preferred embodiment of the invention consists in the aggregate comprising sand and/or coarse aggregate. Sand 0/2 with a weight proportion of 400 to 1000 kg/m.sup.3 and aggregate 2/8 of 400 to 800 kg/m.sup.3 can be provided here. Other aggregate mixtures can also be provided depending on the recipe.

(6) Furthermore, it has turned out to be particularly advantageous that a content of binding agent of at least 400 kg/m.sup.3 concrete is provided. In this case the binding agent can have a content of cement of preferably at least 75 kg/m.sup.3 and fly ash of at least 250 kg/m.sup.3. It is particularly preferable if per cubic meter of concrete, binding agent is provided that provides a content of cement of 100 kg/m.sup.3 and of fly ash in a quantity of 300 to 350 kg/m.sup.3 sealing wall mass.

(7) A particularly good ratio of impermeability to strength is achieved according to a further development of the invention in that the binding agent has a ratio of cement to fly ash of between 2% and 60%. Thus, for example, there are two parts cement to 98 parts fly ash or 40 parts cement to 60 parts fly ash. The rest of the recipe can consist of aggregate, additives and water. Here the water content is significantly higher than in structural concretes. A ratio of cement to fly ash of at least 7%, in particular of at least 10%, is preferably provided.

(8) Another improvement in the sealing wall building material according to the invention can be achieved in that at least one additive, in particular a flow agent and/or a retarder, is provided. The flow capability of the raw sealing wall mass can be influenced and set in a desired manner using a flow agent. The setting behavior of the sealing wall mass can be influenced and set using a so-called retarder. In particular, a setting time can be extended in this way, so that sufficient time remains for transporting and processing the sealing wall building material.

(9) It has also proved particularly advantageous if the fresh mass has a bulk density of between 2.0 g/cm.sup.3 and 2.4 g/cm.sup.3. Fresh mass is to be understood here as the finished sealing wall building material in its still fluid, uncured state. With respect to flow capability, it is preferred that a flow spread a is between 57 cm and 63 cm, wherein the flow spread is to be measured in accordance with DIN EN 206: 2014-07.

(10) In a further development of the sealing wall building material according to the invention, it is further preferred that a monoaxial compressive strength q.sub.u of q.sub.u≤500 kN/m.sup.2 is provided at an age of 7 days and of 1000 kN/m.sup.2≤q.sub.u≤5000 kN/m.sup.2 at an age of 28 days. In this value range the sealing wall building material is sufficiently stable, but at the same time still possesses a certain adaptability, for instance to changes of shape and settlement, so that a sealing wall manufactured from this is sufficiently stable.

(11) Furthermore, the invention relates to a sealing wall or a sealing wall element, which is manufactured using a sealing wall building material that was described previously. Such a sealing wall or such a sealing wall element, which can also be a base slab, for example, can be manufactured simply and economically, wherein good impermeability and strength are provided at the same time.

(12) The invention further relates to a method for producing a sealing wall building material, in which a binding agent is mixed with cement and aggregate in a single mixer with the addition of water to form the sealing wall building material, wherein the binding agent comprises a mixture of cement and fly ash and the sealing wall building material is free of a clay material, and wherein an impermeability with a kf value of 10.sup.−7 m/s and less is set.

(13) The sealing wall building material described previously can be manufactured in a simple and efficient manner using the method according to the invention.

(14) The impermeability of a sealing wall building material according to the invention preferably lies in the range of a kf value of 10.sup.−10 m/s and less.