JPH01231971A - Production of spray concrete - Google Patents

Abstract

PURPOSE: To obviate the generation and rebonding of dust during spraying by supplying the resin-contg. concrete obtd. by mixing dry concrete, a resin, a hardener and other additives and adding water to this mixture to a nozzle. CONSTITUTION: The homogeneous mixture is prepd. by mixing the reactive resin and the hardener together with the soluble additive to be arbitrarily incorporated into the final mixture with the required min. volume of the water. This mixture is added to a hydraulic binder, aggregate and solid additives in a mixer. These components are sufficiently mixed before the addition of the resin mixture described above. The dry mixture is then supplied to a dry spraying of an ordinary rotor type where the free flowing dry mixture is sent under pressurization of compressed air to the spraying nozzle where the required volume of the water arbitrarily contg. the curing accelerator is added to the mixture to obtain the resin-contg. concrete.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a new method for producing resin-containing concrete by spraying and to a dry mixture used in the method.

Resin-containing concrete with improved mechanical properties can be produced by conventional methods or by spraying processes. In the latter case, it is proposed to feed the nozzle through separate channels with the usual dry components (hydraulic binders and aggregates) from one side and the emulsifying resin from the other with hardener and water. . Consequently, special equipment is required, especially if, as is preferred, the emulsifying resin and hardener are added in two different liquid streams. Furthermore, the dry components from one and the liquid stream from the other are not homogeneously mixed.

mixing the dry ingredients with the resin and curing agent and additives;
It has now been found that resin-containing concrete can be produced by a spray process in which the dry mixture is fed into a spray nozzle and water is added thereto. This method ensures a homogeneous mixture of all components, spraying eliminates dust generation and recombination during the process, and dry spraying allows the use of the usual equipment for the process.

Another aspect of the invention is the dry mixture obtained by mixing hydraulic binder, aggregate, reactive resin and curing agent, and optionally additives in the first step of the process. This dry mixture is free-flowing and can be stored for even several hours.

The hydraulic binder used in the process and in the dry mixture of the invention can be a portland cement, an alumina cement or a mixed cement, such as pozzolana cement, slag cement or other types, with portland cement being preferred. In addition to the usual aggregates such as sand and coarse aggregates, steel, glass or polymer fibers, pigments and fillers, solid additives such as plyash, silica, lime and other known substances are used. May contain.

The reactive resins used in the process and in the dry mixture according to the invention are preferably epoxy resins of the type commonly used in the construction sector. Other known resins are incyanate addition products or polyester resins. The curing agent added for curing the epoxy resin can be any known curing agent, such as the well-known polyamines or polyaminoamides used for this purpose.

Soluble additives which can be added to the dry mixture used in the process according to the invention include the usual additives such as superplasticizers, set retarders, air entrainers (a
ir-entraining agents), anti-frost agents, etc.

However, hardening accelerators such as known aluminates, silicates, alkalinity agents or mixtures thereof are preferably added to the water, which is sprayed onto the mixture in a nozzle.

In the method according to the invention, the reactive resin, curing agent, and optionally any soluble additives to be included in the final mixture, are preferably first mixed with the minimum amount of water necessary to obtain a homogeneous mixture. do.

This mixture is added to the hydraulic binder, aggregate, and any solid additives in a mixer, and the ingredients are preferably thoroughly mixed before adding the resin mixture described above. The dry mixture according to the invention is then fed into a conventional rotor-type drying spray device, where the free-flowing dry mixture is sent under pressure (compressed air) to a nozzle and optionally cured. Wet with the required amount of water containing accelerator.

The amounts used are preferably as follows: this basic mixture of cement, aggregate and solid additives contains from 8 to 80%, preferably 15-80%, all percentages expressed as weight percentages relative to the total amount of the mixture. 30% cement, 20-92%, preferably 70-85%
of aggregate and 0 to 20%, preferably 0-10%
Contains solid additives. The dry mixture according to the invention comprises:
Preferably from 2 to 20% based on the weight of the cement.
of, preferably 3-1 part % of epoxy resin, 2 to 2
Contains 0%, preferably 3-10% curing agent and O to 20%, preferably 0-2% soluble additives. This mixture is made from O to 2 O based on the weight of the curing agent.
00%, preferably 50-120% water.

A total of 30-50% water, based on the weight of cement, including the water used to prepare the above mixture, is added to this mixture in the spray nozzle to form the concrete mixture to be sprayed. It may also contain up to 10% hardening accelerator, again based on the weight of the cement.

In the following examples, all parts are by weight.

EXAMPLE 1 part epoxy resin, 10 parts curing agent and 2 parts superplasticizer are mixed with 10 parts water. This mixture is added to a premix of 650 parts aggregate (0-4 mm) and 150 parts Portland cement. The resulting dry mixture is fed into a rotor-type drying spray apparatus and wetted with 50 parts of water. The sprayed concrete obtained in this way was tested according to Swiss standard 5N640461 and showed no damage after 4θθ cycles of freezing and molten salt treatment.

The main features and aspects of the invention are as follows.

1. Mixing the dry ingredients with the resin and curing agent and optionally additives, feeding the dry mixture into a spray nozzle, and adding water to the mixture just before the spraying process. A method for producing resin-containing concrete by attaching.

2. The method of paragraph 1 above, wherein the resin, curing agent and optionally soluble additives are first mixed with a minimum amount of water.

3. A method according to paragraph 1 above, in which the hydraulic binder, aggregate and optionally solid additives are first mixed before addition of the mixture obtained by the method according to paragraph 2 above.

4. Dry concrete mixture consisting of hydraulic binders, aggregates, resins, hardeners and optionally soluble and/or solid additives.

5. 8 to 80% hydraulic binder, all percentages based on the total weight of the mixture, 20 to 92%
% aggregate and O to 20% solid additives.

6. Dry mixture according to paragraph 5 above, consisting of 15-30% hydraulic binder, 70-85% aggregate and 0-1θ% solid additives.

7. 2 to 20% epoxy resin, all percentages based on the weight of hydraulic binder, 2 to 2
A dry mixture as claimed in any of paragraphs 4 to 6 above containing 0% curing agent and 0 to 20% soluble additives.

8.3-10% resin, 3-10% hardener and 0-
Dry mixture according to paragraph 7 above containing 2% soluble additives.

9. Dry mixture according to paragraph 7 above, containing from 0 to 200% water based on the weight of the curing agent.

10. Dry mixture according to paragraphs 8 and 9 above containing 50-120% water.

Claims (1)

[Claims] 1. Mixing the dry ingredients with the resin and curing agent and optionally additives, feeding the dry mixture to the spray nozzle, and adding water to the mixture immediately before the spraying step. A method for producing resin-containing concrete by spraying, comprising the steps of: 2. Dry concrete mixture consisting of hydraulic binders, aggregates, resins, hardeners and optionally soluble and/or solid additives.