CZ23178U1 - High-strength geopolymeric composite - Google Patents

Description

Technical field

The present invention relates to a high strength geopolymers composite comprising a solid filler and a two component geopolymers consisting of a solid component and a liquid component.

Background Art

High-strength geopolymers composites are known, their chemical composition and proportions of their individual components vary according to the purpose of the product's use and the time required to obtain the required strength of the geopolymic composite. The aim is to ensure that geopolymers composites achieve the necessary strength in a short time without the need to increase their temperature in order to accelerate chemical reactions when curing the material.

The geopolymer matrix consists of a cured mixture of alkali silicates and other components based on silicon oxides, aluminum and other elements. This material, unlike organic resin composites, is non-flammable. Thus, geopolymers or inorganic polymers are alkali-activated aluminosilicates in which curing takes place by polymerization as opposed to Portland cement binders, where the curing takes place by hydration of clinker minerals. All these steps take place in geopolymers in a highly alkaline medium, which is a condition for dissolving aluminosilicates. The solubility of aluminosilicates can be increased by heating them to a temperature of several hundred degrees Celsius. However, subsequent polymerization results in a new amorphous or crystalline phase. It has been found that the addition of calcium-containing feedstock accelerates the solidification process and contributes to high strengths within a few days of maturation of the geopolymic composite.

Thus, for example, U.S. Pat. No. 4,509,985 discloses and discloses a mineral polymer based on a mixture of metakaolin and an alkaline potassium and / or sodium silicate activator, and in the presence of potassium and / or sodium hydroxide, with the addition of blast furnace slag. The disadvantage of this material is the use of potassium hydroxide or the like. sodium for the preparation of the alkaline activator and its amount used, resulting in a longer setting time of the mixture at room temperature and thereby a slower growth of the strength of the geopolymers.

U.S. Pat. No. 4,642,137 discloses a binder consisting of 100 parts by weight of metakaolin, from 20 to 70 parts by weight of ground blast furnace slag, from 85 to 130 parts by weight of fly ash or calcined lamella, from 70 to 215 parts by weight of amorphous silica from 55 to 145% by weight. parts of an alkali silicate containing 0 to 90 parts by weight of sodium and / or potassium hydroxide. A disadvantage of this binder is the content of sodium hydroxide and / or potassium hydroxide as an alkaline activator.

U.S. Pat. No. 5,482,549 discloses a cement comprising 20 to 80% ground blast furnace slag, 30 to 70% ground power fly ash, 2 to 15% ground Portland cement clinker and 2 to 12% solid hydrated sodium silicate with a SiO silicate module ₂ : Na ₂ O = 0.8: 1 to 1.2: 1.

Geopolymers cement is disclosed in U.S. Pat. No. 5,372,640 and contains 40 to 140 parts by weight of metakaolin, 20 to 70 parts by weight of ground blast furnace slag,

85 to 130 parts by weight of fly ash or calcined leaf, 40 to 500 parts by weight of a special type of amorphous silica and 5 to 60 parts by weight of an alkali silicate containing 1 to 50 parts by weight of sodium and / or potassium hydroxide. A disadvantage of this process for the production of geopolymers is the use of sodium and / or potassium hydroxide for the preparation of an alkaline activator.

U.S. Pat. No. 7,229,491 discloses a geopolymers cement suitable for construction which, in addition to metakaolin, contains ground blast furnace slag having an average particle size of 15-25 [mu] m and an alkali activated calcined weathered granite which partially

-1CZ 23178 U1 or completely replaces metakaolin. The alkaline activator used is a potassium alkaline activator with a silicate module of SiO ₂ : K ₂ O = 1.27: 1, which can only be achieved by using potassium hydroxide.

U.S. Pat. No. 7,311,964 discloses a method for preparing a composite system using alkali-resistant glass fibers with epoxy-based finish, wherein the adhesion between the fibers and the inorganic matrix is improved by applying an additional resin interlayer. The disadvantage of this is the need for a further manufacturing operation.

The purpose of the technical solution is to create a geopolymic composite with good mechanical properties, in particular high strength, which can be achieved within a few days even with maturing of the composite at normal ambient temperature between 20 and 30 ° C.

The essence of the technical solution

The aforementioned assumptions are fulfilled by a high strength geopolymers composite comprising a solid component as a filler and a two component geopolymer binder consisting of both a solid component and a liquid component. The solid component and the liquid component of geopolymers bind to the geopolymers composite matrix. The essence of the solution is that the solid component of the two-component geopolymers binds metakaolinite-containing raw materials and ground blast-furnace slag. The liquid component of the two-component geopolymers binds sodium alkali activator. The geopolymer composite then contains 10 to 30 weight percent of the metakaolinite-containing feedstock, 5 to 15 weight percent of the ground blast furnace slag and 5 to 15 weight percent sodium alkali activator. The filler solid component of this composite is stone dust in an amount of 20 to 40 weight percent and also 20 to 40 weight percent of power plant fly ash.

The metakaolinite-containing feedstock consists of at least 40% by weight of Al ₂ O ₃ . Such an Al ₂ O ₃ content in the feedstock provides greater solubility of aluminum and silicon in an alkaline environment.

Such a raw material is more reactive and has a greater ability to form a solid matrix. This feedstock mixed with ground granulated blast furnace slag forms a preferred solid component of the two-component geopolymers binder. The sodium alkaline activator forming the liquid component of the bicomponent geopolymers binds preferably the liquid sodium water glass with the SiO ₂ silicate module: Na ₂ O = 1.6: 1 to 2.1: 1. The sodium water glass used is free of sodium hydroxide. Water is mixed into the liquid component of the two-component geopolymer binder to produce a water-to-weight ratio of water to the weight ratio of water of 1; 0.1 to 0.9. Thereafter, the weight ratio of the solid component of the two-component geopolymer binding agent to the weight ratio of the liquid component of the two-component geopolymers binder is in the range of 1: 0.1 to 1: 1.

From the above-mentioned composition of geopolymers composite, it is assumed that the weight ratio of the filler solid component to the weight ratio of the two component geopolymers binder per se is in the range of 1: 0.5 to 1: 4.17,

In the preparation of the two-component geopolyme binder, a solid component of a two-component geopolymer binder and, in particular, a liquid component of a geopolymer binding agent is prepared.

Both parts of the solid component of the two-component geopolymers binder, i.e. metakaolinite and ground blast furnace slag, are mixed in the indicated weight ratios in the blender and mixed well. The liquid component of the two-component geopolymer binder is also sufficiently mixed with water in the indicated weight ratios. The two-component geopolymer binder is then prepared by adding a liquid component to the solid component of the two-component geopolyme binder. Mixing of the solid component and the liquid component of the bicomponent binder is carried out just prior to use, adding a filler to the mixture, i.e. granite and / or basalt stone 5 to 20 mm in weight ratios and / or power fly ash in said mass. ratios, thereby producing a geopolyme composite. In addition to granite and / or basalt stone and power plant fly ash, these amounts may be added

-2C 23178 U1 of quartz sand with a grain size of 0,5 to 2,0 mm and / or the abovementioned amounts of nanofibres or microfibers as an additional solid component, respectively. filler solids. The use of nanofibres or listed types of microfibers can be applied either individually or in a mixture. The mixture should be well homogenized in a mixer or mixer. The resulting mixture can be used as a geopo5 lymph mortar or as a geopolymer concrete or as a geopolymer reinforced composite.

Examples of technical solutions

Example 1

The solid component of the high strength geopolymers binder was made up of 20% by weight of the metakaolinite-containing feedstock and 10% by weight of the ground blast-furnace granular slag, based on the dry matter of these substances. The liquid component of the high strength geopolyme binder is the% by weight sodium alkali activator which is the liquid sodium water glass with the SiO ₂ silicate module: Na ₂ O = 1.8: 1.

After thoroughly mixing the solid and after diluting the liquid sodium water glass with water in a ratio of 1: 0.5, the liquid component was mixed into the solid component of the high strength geopo15 lymphoid binder. In order to form the high strength geopolymers composite, fillers were added to the mixture to form 30% by weight of rock dust and 30% by weight of fly ash.

From the homogenized mixture it is possible to create various shaped articles, for example ornamental, architectural elements, castings for molds, cladding panels, products for the repair of buildings and vehicles20 age, cover plates, tombstones and other products for construction such as artificial stone, prisms, curbs, etc. .

The products can be mechanically machined, sanded and polished after their hardening. These geopolymers composites exhibit high strength, heat resistance up to 1200 ° C, acid resistance and also high frost coefficient including dimensional stability.

Depending on the content of the individual components in the high-strength geopolymers composite, the setting time of the two-component geopolymers is based on two hours to about five and a half hours. The advantage is that this is done at normal ambient temperature, i.e. between 20 and 30 ° C. Also, the onset of setting time of two-component geopolymers varies from one hour to about four hours. The actual solidification time of the two-component geopolymer binder is already relatively very short.

Example 2

In the preparation of the solid component and the liquid component of the high strength geopolymer binding agent in accordance with Example 1, 40% by weight of the power plant fly ash and further 20% by weight of the quartz stone dust are mixed into the mixture. The achieved structure of high-strength geopolymic composite is refined by using a larger amount of power plant fly ash and will colorize the quartz stone dust used together with the color of the power plant fly ash used.

Claims (6)

PROTECTION REQUIREMENTS A high-strength geopolymer composite comprising a solid component as a filler and a two-component geopolymer binder consisting of a solid component and a liquid component 40, wherein the solid component of the two-component geopolymic binder comprises metakaolinite-containing feedstocks and ground blast-furnace granulated slag and the liquid component of the two-component geopolymic binder comprises sodium alkaline activator, wherein the geopolymers composite comprises 10 to 30% by weight of metakaolinite-containing feedstock; -3EN 23178 Ul 15% by weight of ground blast furnace slag granulated and 5 to 15% by weight of sodium alkaline activator, and that the solid component in the form of filler is from 20 to 40% by weight of stone dust and from 20 to 40% by weight of fly ash. 5 High-strength geopolymers composite according to claim 1, characterized in that the metakaolinite-containing feedstock constitutes at least 40% by weight of Al ₂ O ₃ . The high-strength geopolymers composite of claim 1, wherein the sodium alkaline activator is a liquid sodium water glass having a SiO ₂ : Na ₂ O = 1.6: 1 to 2.1: 1 silicate module. io A high-strength geopolymer composite according to claim 3, wherein the weight ratio of liquid waterglass of sodium to the weight ratio of water is in the range of 1: 0.1 to 1: 0.9. A high-strength geopolymic composite according to claim 1, characterized in that the weight ratio of the solid component of the two-component geopolymic binder to the weight 15 a ratio of the liquid component of the two-component geopolymic binder ranging from 1: 0.1 to 1: 1. 6. The high tenacity geopolymer composite of claim 1 wherein the weight ratio of the solid component in the form of filler to the weight ratio of the two-component geopolymic binder is in the range of 1: 0.25 to 1: 1.5.