KR101787374B1 - Self Leveling Mortar Compound Having High Abrasion resistance - Google Patents

Abstract

The present invention relates to a mortar composition based on cement, and relates to a self leveling mortar composition improved in strength and abrasion resistance by replacing part of silica sand applied as fine aggregate and filler with crumbly slag.
The present invention relates to a cement paste composition comprising 7 to 17 parts by weight of one kind of ordinary Portland cement, 10 to 25 parts by weight of alumina cement containing 30 to 40 wt% of Al ₂ O ₃ , 7 to 20 parts by weight of anhydrous gypsum, 20 to 30 parts by weight of limestone fine powder, 20 to 40 parts by weight of a mixed aggregate composed of 40 to 80% by weight of crushed slag 20 to 60% by weight, and 0.05 to 0.30 part by weight of a fluidizing agent, based on 100 parts by weight of the SL mixture ≪ / RTI > to 30 parts by weight of a mixed self-leveling mortar composition.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a self leveling mortar composition having high abrasion resistance,

The present invention relates to a mortar composition based on cement, and relates to a self leveling mortar composition improved in strength and abrasion resistance by replacing part of silica sand applied as fine aggregate and filler with crumbly slag.

Conventional cement-based SL (Self Leveling) material has higher abrasion resistance than ordinary concrete floor but remains at AR3 level of EN13813 standard (2002). [Table 1] summarizes the abrasion resistance rating standards of EN13813.

Performance Class Service Condition Test Limits (mm) Special Scratches or dragging of steel objects from the floor, impact or wear of the floor caused by running of steel, hard nylon or neoprene wheels 0.05 AR1 Steel, Hard Nylon or Neoprene wheels 0.10 AR2 Hard Nylon or Neoprene wheels wear 0.20 AR3 Wear caused by running of rubber tires 0.40

Urethane and epoxy-based SL materials exhibit abrasion resistance higher than AR1 grade, but they are not economical to use for large-scale factories due to high cost. In addition, the rate of change of shrinkage length of urethane and epoxy-based SL materials is smaller than that of cement mortar, but there is a cracking problem due to drying shrinkage after application.

1. EP 10-0967949 "Environmentally friendly inorganic flooring composition and method of construction using the same" (2010.07.06.) 2. Registration No. 10-1586654 "Method of constructing air shortening floor heating floor" (Feb.

1. Lee Sang Soo, Song Ha Yong and Kim Eul Yong, "An Experimental Study on the Engineering Properties of Concrete Using Fine-Grained Slag Fine Aggregate", Journal of Korean Society of Building Construction, Vol.6 No.3, 2006.9, p.107-114 2. Jin-Chul Kim, Jae-Won Shim, and Kyu-Seong Cho, "Evaluation of Applicability of Pavement Concrete for Fine Aggregate Slag from Slag Cement", Korea Society of Concrete Structures, 2005.5, p.85-88

INDUSTRIAL APPLICABILITY The present invention can be economically applied to semiconductor factories and automobile factories that require precise floor finishes, has improved strength characteristics as floor finishes, has improved wear resistance, and has a defect caused by floor wear and drying shrinkage cracks The mortar composition of the present invention can be reduced.

The present invention relates to an alumina cement composition comprising 7 to 17 parts by weight of 11-kind ordinary Portland cement, 10 to 25 parts by weight of alumina cement containing 30 to 40% by weight of Al ₂ O ₃ , 7 to 20 parts by weight of anhydrous gypsum, 20 to 30 parts by weight of limestone fine powder, 20 to 40 parts by weight of a mixed aggregate composed of 40 to 80% by weight of crushed slag 20 to 60% by weight, and 0.05 to 0.30 part by weight of a fluidizing agent, based on 100 parts by weight of the SL mixture ≪ / RTI > to 30 parts by weight of a mixed self-leveling mortar composition.

The SL mixture is a mixture of the remaining components except the compounding water in the self-level mortar composition provided by the present invention, and the same applies to [Claims] and [Specific contents for carrying out the invention].

The crumbled slag may have a particle size of 0.01 to 0.6 mm, a hardness of 8 or more, a specific gravity of 3.4 to 3.6, and a water absorption of 0.2 wt% or less to improve the strength and abrasion resistance of the magnetic horizontal mortar. In addition, the above-mentioned culvert slags contain 18 to 28 wt% of CaO and 0.2 to 0.4 wt% of Free-CaO in the CaO is used to increase the strength due to the expansion effect within a proper range and to reduce cracks .

The SL mixture may contain 3-7 parts by weight of polymer resin or 0.05-0.25 parts by weight of lithium carbonate, 0.1-0.3 parts by weight of an antifoaming agent, 0.02-0.20 parts by weight of a curing retarder, 0.03-0.15 parts by weight of a thickener, and 0.01-0.15 parts by weight of a stabilizer 0.01 To 0.10 part by weight, and the polymer resin, the lithium carbonate, the antifoaming agent, the curing retarder, the thickener and the stabilizer may all be applied together.

The self-leveling mortar composition prepared according to the above-mentioned method exhibits physical properties such as a slump flow of hard mortar of 220 to 250 mm, a compression strength of 30 to 40 MPa at 28 days of age, and a rate of change of -0.02 to 0.00% ), It can be expressed in AR1 grade or higher (AR1 ~ S grade).

The self-leveling mortar composition according to the present invention has the following effects.

1. The present invention can be economically applied to semiconductor factories, automobile factories, and the like that require precise floor finishes.

2. Improvement of strength property as floor finish and improvement of abrasion resistance (wear grade AR1 or more) reduces flaws caused by bottom wear and drying shrinkage cracks due to heavy load and movement.

The present invention relates to a cement paste composition comprising 7 to 17 parts by weight of one kind of ordinary Portland cement, 10 to 25 parts by weight of alumina cement containing 30 to 40 wt% of Al ₂ O ₃ , 7 to 20 parts by weight of anhydrous gypsum, 20 to 30 parts by weight of limestone fine powder, 20 to 40 parts by weight of a mixed aggregate composed of 40 to 80% by weight of crushed slag 20 to 60% by weight, and 0.05 to 0.30 part by weight of a fluidizing agent, based on 100 parts by weight of the SL mixture ≪ / RTI > to 30 parts by weight of a mixed self-leveling mortar composition.

The above-mentioned one ordinary Portland cement and alumina cement are binders.

The alumina cement contributes to the development of toughness and high strength by the Al ₂ O ₃ component. Division rigidity and therefore if the Al ₂ O ₃ component in the alumina cement exceeds be more than 30wt%, however, 40wt% is inflatable is increased stability of the curing process down to a high intensity expressed, in the present invention, A1 ₂ O ₃ is 30 to The above-mentioned alumina cement containing 40 wt% should be applied.

When the alumina cement is less than 10 parts by weight, the effect of early strength development is insufficient and the absolute amount of the binder is reduced, so that the mortar structure is not densified and the strength is lowered. On the other hand, if the alumina cement exceeds 25 parts by weight, the setting speed is increased, which makes it difficult to secure the working time.

The anhydrous gypsum is calcium sulfate (CaSO ₄ ) having no crystal number and reacts with the alumina cement to form an acicular type ettringite to densify the mortar structure and compensate for drying shrinkage. The use of semi-gypsum improves the compressive strength, but reduces the abrasion resistance due to the increase in the embrittlement of the mortar structure, so anhydrous gypsum is applied in the present invention.

When the alumina cement is used in an amount of 10 to 25 parts by weight, when the anhydrite is used in an amount less than 7 parts by weight, the aforementioned shrinkage compensation effect becomes insignificant. When the anhydrite is more than 20 parts by weight, the expansion performance becomes excessively large. Microcracks may occur.

The limestone fine powder is applied to adjust the particle size of the dry mortar for proper fluidity of the mortar composition. Therefore, 20-30 parts by weight of the limestone fine powder having a powder degree of 2,300-2,800 cm2 / g is applied.

When the amount of the limestone fine powder used is less than 20 parts by weight, the fluidity is increased but the viscosity is lowered and the material separation occurs. When the amount of the limestone fine powder used exceeds 30 parts by weight, the viscosity is increased to make it difficult to exhibit high fluidity, do.

In the present invention, 20 to 40 parts by weight of a mixed aggregate composed of 40 to 80% by weight of silica sand and 20 to 60% by weight of crushed stone slag is included. The silica sand is applied as a fine aggregate to a general cement based SL material. In the present invention, a part of silica sand is replaced with a cobbled slag.

In the present invention, the silica sand serves as a fine aggregate and a filler, and it is preferable to use No. 7 or No. 8 silica.

The cobbled slag is formed by spraying air having small water particles at a predetermined blowing pressure to form a spray zone and passing the molten steel slag directly to the spray zone through an atomizing process, It is a spherical crystal with a very high hardness.

The tumbled slag has a higher hardness than that of silica sand and has a low water absorption rate, thereby increasing the bonding strength between the fine aggregate and the cement paste, thereby improving the strength and abrasion resistance of the horizontal mortar. The tumbled slag used in the present invention is a tumbled slag having a particle size of 0.01 to 0.6 mm, a hardness of 8 or more, a specific gravity of 3.4 to 3.6 and a water absorption of 0.2 wt% or less. A certain amount of slag and silica sand were randomly sampled and the results of the tests for each property were summarized.

Item Triticale slag (PS) Silica sand importance 3.54 2.65 Hardness (moss) 8 7 Absorption Rate (%) 0.1 0.63

When the granular slag has a particle size exceeding 0.6 mm, there may arise a problem in surface planarization when the thickness of the magnetic horizontal mortar is 3 to 5 mm.

In the present invention, a crushed slag containing 18 to 28 wt% of CaO and 0.2 to 0.4 wt% of Free-CaO in CaO may be applied. Table 3 below shows the result of analyzing the chemical composition of a certain amount of the crushed stone slag applied to the present invention.

ingredient SiO ₂ CaO Al ₂ O ₃ T-Fe MgO S MnO TiO ₂ content
(wt%) 17.7 26.2 12.2 21.2 5.3 0.09 7.9 0.7

When the CaO content in the crushed slag is 18 ~ 28wt%, the pore is filled due to the expansion effect, and the structure is densified and the shrinkage compensation effect is reduced to reduce the crack. Free-CaO hydration reaction (free-CaO + H ₂ O → Ca (OH) ₂ ) of trace amount (0.2 to 0.4 wt% of CaO content) in the above-mentioned crushed slag contributes to the shrinkage compensation effect. (In Table 2, the difference is more than 6 times), and thus the shrinkage amount is reduced, which contributes to prevention of cracks due to drying shrinkage.

However, when the CaO content is less than 18 wt%, the strength increase and the shrinkage compensation effect become insignificant. When the CaO content exceeds 28 wt%, cracks may occur due to excessive expansion.

In the present invention, 0.5 to 0.3 parts by weight of the fluidizing agent is mixed in the SL mixture to increase the compressive strength of the self-leveling mortar and to secure the fluidity of the unhardened mortar by reducing the mixing amount. Accordingly, the water content in the present invention is 20 to 30 parts by weight based on 100 parts by weight of the SL mixture.

The self-horizontal mortar composition provided by the present invention further comprises a polymer resin to improve the abrasion resistance, bending strength and tensile strength of the cured mortar. The optimum addition amount of the polymer resin for the expression of the abrasion resistance, flexural strength and tensile strength of the hardened mortar is 3 to 7 parts by weight in the SL mixture. As the polymer resin, a vinyl-based redispersed powder resin can be applied.

The present invention may further comprise 0.05 to 0.30 parts by weight of lithium carbonate in the SL mixture to increase the early strength after solidification of the self-level mortar composition. When the lithium carbonate is used in an amount less than 0.05 parts by weight, it is difficult to secure an open time. When the lithium carbonate is used in an amount exceeding 0.30 parts by weight, delay of coagulation and separation of materials may occur.

Further, the present invention can further add 0.05 to 0.3 parts by weight of defoaming agent to the SL mixture to remove entrained air in the self-leveling mortar composition and to obtain a clean finished surface. When the defoaming agent is added in an amount less than 0.05 part by weight, it is difficult to remove air bubbles. When the defoaming agent is added in an amount exceeding 0.3 parts by weight, the economical efficiency is lower than the defoaming effect. As the antifoaming agent, a polyglycol-based agent can be applied.

0.02 to 0.15 parts by weight of a curing retarder may be added to the SL mixture in order to retard the coagulation of the self-leveling mortar composition and ensure workability during the course of the work. However, when the curing retardant is added in an amount of less than 0.02 parts by weight, it is difficult to secure an open time. When the curing retardant is added in an amount exceeding 0.15 parts by weight, delay of coagulation and separation of materials may occur.

In order to improve the adhesion of the self-level mortar composition and to prevent material separation, 0.03 to 0.15 part by weight of a thickener may be added to the SL mixture, and methyl cellulose may be used as the thickener.

In addition, in order to prevent the material separation of the self-leveling mortar composition and increase the stability against variation in the mixing amount, 0.01 to 0.10 part by weight of the stabilizer may be added to the SL mixture. When the stabilizer is added in an amount of less than 0.01 part by weight, the effect is not exhibited. When the stabilizer is applied in an amount exceeding 0.10 part by weight, the flowability may be lowered. As the stabilizer, guar gum may be applied.

The following Table 4 is a blending table of self-shrinking mortar prepared so as to exhibit a property equal to or greater than that of existing SL materials by using the above-mentioned characteristics of alumina cement, anhydrous gypsum, limestone fine powder, polymer resin, lithium carbonate and the like. Hereinafter, the self-shrunk mortar composition prepared from the formulation shown in [Table 4] is referred to as Test Example 1.

Composition component Weight (kg) Number of ingredients 22 1 species ordinary Portland cement 12 Alumina cement 16 Anhydrous plaster 14 Limestone powder 23 Silica sand 31.37 Polymer resin 3 Fluidizing agent 0.10 Defoamer 0.10 Retarder 0.10 Lithium carbonate 0.14 Thickener 0.12 Stabilizer 0.07

The following [Table 5] and [Table 6] are the same as those in Test Examples 2 to 6 in which the conventional SL material and the silica sand of Test Example 1 and Test Example 1 were replaced with the cobalt slag (PS) in the range of 20 to 100 wt% And the test results such as fluidity, coagulation speed, compressive strength, length change, abrasion resistance, material separation, etc. are summarized. Particularly, in the abrasion resistance test, both the existing SL material and the test examples 1 to 6 were carried out under the conditions of the casting thickness of 4 mm.

division
PS replacement rate
(Wt% against silica sand) Flow (mm) Condensation time (min) Compressive strength (MPa) 0 minutes 20 minutes Fresh closing 1 day 7 days 28th Original SL material - 220 220 93 112 19.0 23.8 28.4 Test Example 1 0 241 239 90 117 22.1 26.1 33.6 Test Example 2 20 242 240 87 114 22.4 27.1 36.8 Test Example 3 40 250 251 92 125 23.1 28.7 37.2 Test Example 4 60 254 250 90 115 21.0 26.3 34.1 Test Example 5 80 255 255 91 120 18.1 22.4 27.7 Test Example 6 100 256 258 94 123 17.9 21.6 27.5

division PS replacement rate
(Wt% against silica sand) Change in length
(%) Abrasion resistance
(mm) Wear rating Material separation Original SL material - -0.025 0.344 AR3 none Test Example 1 0 -0.018 0.251 AR2 none Test Example 2 20 -0.008 0.015 S none Test Example 3 40 -0.006 0.010 S none Test Example 4 60 -0.004 0.049 S none Test Example 5 80 -0.004 0.144 AR2 Occur Test Example 6 100 -0.009 0.416 Outside grade Occur

Test Example 1 showed improved compressive strength and abrasion resistance compared to conventional SL materials, and showed little change in length. However, the wear rating was still AR2 grade according to EN13818 (2002) standard.

In Test Examples 2 to 4, in which the substitution rate of the crumbled slag (PS) relative to the silica sand was 20 to 60 wt% when the silica sand was replaced with the crust slag (PS) in the composition composition of Test Example 1, ), And the slump flow was 220 ~ 250mm, the compressive strength was 30 ~ 40MPa at 28 days of age and the change rate of length was -0.02 ~ 0.00%.

In Test Example 5 and Test Example 6 in which the substitution ratio of the crust slag (PS) to the silica sand was 80 to 100 wt%, the degree of wear decreased and the material separation occurred.

The present invention has been described in detail with reference to the preferred embodiments. However, it should be understood that the present invention is not limited to the above-described embodiment, but may be modified and changed without departing from the gist of the present invention. The claims of the present invention thus include such modifications and variations.

Claims (7)

1 to 10 parts by weight of alumina cement containing 7 to 17 parts by weight of ordinary Portland cement and 30 to 40% by weight of A1 ₂ O ₃ , 7 to 20 parts by weight of anhydrous gypsum and 20 to 200 parts by weight of a limestone fine powder having a powder fraction of 2,300 to 2,800 cm & 20 to 40 parts by weight of a mixed aggregate composed of 40 to 80% by weight of crushed slag and 20 to 60% by weight of silica sand and 0.05 to 0.30 part by weight of a fluidizing agent, based on 100 parts by weight of the SL mixture, Mixed,
The above crushed stone slag has a particle size of 0.01 to 0.6 mm, a hardness of 8 or more, a specific gravity of 3.4 to 3.6, a water absorption of 0.2 wt% or less, CaO of 18 to 28 wt%, and CaO of 0.2 to 0.4 wt% Characterized in that the mortar composition is a self-leveling mortar composition.
delete delete The method of claim 1,
Wherein the SL mixture further comprises 3 to 7 parts by weight of a polymeric resin.
The method of claim 1,
Wherein the SL mixture further comprises 0.05 to 0.25 parts by weight of lithium carbonate.
The method of claim 1,
Wherein the SL mixture further comprises 0.1 to 0.3 parts by weight of a defoaming agent, 0.02 to 0.20 parts by weight of a curing retardant, 0.03 to 0.15 parts by weight of a thickener, and 0.01 to 0.10 parts by weight of a stabilizer.
The method according to any one of claims 1 to 5,
A mortar composition having a slump flow of 220 to 250 mm, a 28-day compressive strength of 30 to 40 MPa, a longitudinal rate of change of -0.02 to 0.00% and an abrasion resistance of an AR1 grade or higher according to EN 13818 (2002).