SU637251A1 - Concrete making method - Google Patents

Description

I

The invention relates to the field of construction, mainly to the manufacture of concrete coatings, such as floors.

Known methods for making concrete l coatings include laying the mixture, vibrating, and then re-vibrating after a certain time. The disadvantage of these methods is the inability to reduce the initial watsocent ratio (W / C) and, as a result, significantly increase the strength, frost resistance and properties of concrete, especially in the upper layer.

There is a known method for producing concrete, which includes coziness of the concrete mix and its compaction with a vibrope, placing filtering material and vacuum shields on the concrete's surface, followed by dewatering by vacuuming

21. This method is closest to the invention in terms of technical drying and the result achieved. It has the following disadvantages: the complexity and duration of processing, the need for energy

high capacity and metal-intensive equipment, uneven strength of concrete over the surface of the coating (below at the joints of vacuum shields and along the edge of the strip). In addition, when implementing both methods, it is necessary to use troweling machines to obtain a smooth and even surface. The aim of the invention is to obtain a smooth surface, increase, density and frost resistance of the surface layer, as well as to simplify the technology by eliminating vacuuming.

This is comprehended by the fact that according to the method of making concrete, which includes laying the mixture, vibro-compaction, placing on the surface of the filter material and subsequent dehydration, a perforated sheet is placed on the filter material and through it vibrating the vibrating rod.

The method is as follows.

HQ compacted with a vibrating rail or on a vibrating slab, concrete is laid. A filtering material, such as cloth, and a perforated sheet on it. Along the laid sheet successively, the vibrator is vibrated and under the influence of uniformly mixed vibration water from the concrete is squeezed onto the surface of the filter material. The perforation rate of the vibro is set depending on the plasticity of the concrete mixture and the thickness of the layer being treated.

Example. The concrete mix of 1: 3, 7: 4.4 with W / C O, 76 and a 2 cm cone sediment is placed in a form 10 cm in height and compacted with a standard vibro pad. Then the filter material — fiberglass cloth — is laid onto the concrete, a 1.5 mm thick perforated aluminum sheet with holes 2 mm in diameter is placed on the concrete, and the vibrating bar at a speed of 1 m / min is mixed through it.

The strength of concrete increases at 3 days old at 60, 7 days old at 4, 28 weeks at 35%. The density of the upper layer increases by 2.3-2.7% compared with the middle layer. The roughness (smoothness) exceeds class IV III with a modulus of sand 2, 3, and the control samples have surfaces of class I III. The roughness of the samples made by the proposed method does not depend on the size of the sand.

When tested for frost resistance of 270 cycles, samples are observed

Only the peeling of the side faces, and the controlled samples are destroyed, the use of water permeability showed that the tiles worn from the upper layer withstand a pressure of 10 atm, and from the middle atm, the tiles of the upper layer of control samples withstand a pressure of 4-7 tm.

Claims (2)

Invention Formula A method of making concrete, which includes laying the mixture, vibrating, placing filter material on the surface and subsequent dehydration, characterized in that, in order to obtain a smooth surface, increase the density and frost resistance of the surface layer, as well as simplify the technology by eliminating vacuuming, perforated material is laid on the filter material the sheet, after which additional surface vibrations are performed by sequential movement of the vibrating bar. Sources of information taken into account in the examination: li Tikhonov V. A. and others. The effect of re-vibration on the change in the structure of cement stone. Concrete and reinforced concrete 1969, № 1О, 2О-1. 2. Smirnov N. А. Technologists of building production, M., GSP, 1959, p. 264.