RU2453431C1 - Method to produce concrete items finished with decorative filler - Google Patents

Abstract

FIELD: construction.

SUBSTANCE: invention relates to the field of construction, namely, to methods to produce concrete items finished with a decorative filler. The method to produce concrete items finished with a decorative filler includes submerging the decorative filler into the concrete mixture poured into a mould. Prior to pouring of the concrete mixture into a mould, sand is filled onto its bottom, where the decorative filler is submerged, and is sprayed with a water-polymer dispersion with subsequent filling with a layer of fine sand.

EFFECT: invention will make it possible to increase durability, decorativeness and architectural expressiveness of concrete items.

4 tbl

Description

The invention relates to construction, and in particular to a method for producing products from decorative concrete.

A known method of producing products with the decoration of concrete surfaces with marble chips by pouring it onto a concrete surface. However, the decorative layer of aggregate (marble chips) is characterized by low adhesive ability and low frost resistance [1, p. 341-346]. Due to the dense structure of the aggregate between the concrete and the aggregate, the adhesive properties are poor, and over time the aggregate falls out.

There is another way to obtain decorative concrete products using concrete with porous aggregates (expanded clay, burnt rocks) by sprinkling them on a concrete mixture poured into a mold [2]. The adhesive properties between the concrete mixture and the aggregate are increased due to the porosity of the aggregate, however, decorativeness, architectural expressiveness are insufficient.

The proposed method relates to the creation of decorative, durable, frost-resistant, architecturally expressive concrete products with a decorative aggregate finish (gravel with a fraction of 20-70 mm) and the creation of enhanced adhesive properties of the aggregate with a concrete base.

The objective of the proposed method for producing concrete products with decorative aggregate finishes is to create increased adhesive properties, as well as durability, decorativeness and architectural expressiveness of the finish.

The bottom line is that in the method of producing concrete products with a decorative filler finish, which is embedded in the concrete mixture poured into the mold, before pouring the concrete mixture into the mold, sand is poured into its bottom, into which the decorative aggregate is embedded and sprayed with water polymer dispersion followed by sprinkling with a layer of fine sand.

To solve the problem, the following method of manufacturing concrete products with decorative decoration with aggregate is proposed.

A layer of very fine sand (Mkr = 1.2-1.5) 5–7 cm thick is poured at the bottom of the mold. Secondary mineral resources can be used, for example, spent molding sand (OFS). The characteristics of the spent molding sand are shown in tables 1, 2.

Table 1 Characteristics of the used sand Components Single for steel and cast iron, ED-1 Facing quick-drying, OB-1 % kg % kg Molding sand 6.5 ... 8 fifty 94 ... 96 260 Reverse mixture 90 ... 92 540 - - Clay 1 ... 1.3 6.3 ... 8 2.8 ... 4.8 7.7 ... 11.3 SDB one 6 - - Liquid glass - - 6.5 ... 7 1.8 ... 2 Sodium hydroxide - - one 3

table 2 Results of the chemical analysis of OFS The content of oxides,% Na ₂ O MgO Al ₂ O ₃ SiO ₂ P ₂ O ₅ K ₂ O 0.49 0.21 7.98 88.46 0,03 <0.03 Cao TiO ₂ MnO Fe ₂ O ₃ total RFP Amount 0.23 0.23 <0.03 1.13 1.09 99.91

1. Decorative aggregate is embedded in the sand to a depth of 1 / 3-1 / 2 of its aggregate thickness in accordance with a given architectural pattern and taking into account the color of the aggregate.

2. The surface of the aggregate is sprayed with a water-polymer dispersion (“Ceresit”) and sprinkled in a single layer of fine sand, which creates a rough surface on the aggregate, providing adhesion to the concrete mix layer. The characteristics of the dispersion "Ceresit" are shown in table 3.

3. Next, the concrete mixture of the given thickness is poured and left for the set of strength characteristic of cement compositions.

4. After the form is removed, the sand crumbles, leaving the exposed part of the decorative aggregate. To enhance the architectural expressiveness, it is possible to wash off the concrete surface with a pebble with a stream of water.

Table 3 Characterization of the dispersion "Ceresit" Structure Cement with mineral fillers and polymer additives Consumption of water and emulsion for the preparation of mortar mixture 0.14 L of water per 0.08 L of Ceresit SS 83 Base temperature when applying mortar from +5 to + 30 ° С Adhesion of mortar to concrete substrates after use in an air-dry environment Not less than 0.5 N / mm Adhesion of mortar to concrete substrates after soaking in water Not less than 0.7 N / mm Adhesion of mortar to concrete substrates after alternate freezing and thawing, 50 cycles Not less than 0.7 N / mm Operating temperature from -50 to + 70 ° С

As a result of testing samples with concrete surface finish with various decorative aggregates, it was found that when finishing with marble chips, shedding of it begins after 35 frost shifts; when decorated with porous aggregates (expanded clay, burnt rock), shedding was observed after 50 frost changes. The surface in this case has no architectural expressiveness. The proposed method for finishing a concrete surface is decorative, architecturally expressive and durable - frost resistance of more than 100 cycles (table 4).

Table 4 Test results for concrete specimens with decorative aggregate Placeholder Type Frost resistance cycle Note Marble chips (known method) 35 Placeholder Expanded clay (known method) fifty Placeholder Burned rock (known method) fifty Loss of individual aggregate grains Pebble (proposed method) one hundred Preserving the integrity and decorativeness of the product

Information sources

1. Bazhenov Yu.M. Concrete technology. / Yu.M. Bazhenov. - M .: Stroyizdat, 2006 .-- 462 p.

2. RU 2091346 "Architectural concrete and the method of its manufacture", cl. C04B 028/00.

Claims (1)

A method of producing concrete products with a decorative aggregate finish that is embedded in a concrete mixture poured into a mold, characterized in that before pouring the concrete mixture into the mold, sand is poured onto its bottom, into which the decorative aggregate is embedded and sprayed with water-polymer dispersion, followed by sprinkling with a layer of fine sand.