KR20160057144A - Outdoor Floor Cement Mortar Composition and Its Application Method - Google Patents

Abstract

The present invention relates to a cement mortar composition for an outdoor floor and a placement method using the same and, more particularly, to a cement mortar composition for an outdoor floor including 15 to 30 wt% of ordinary Portland cement having a fineness of 4,500 to 5,500 cm^2/g and a SO_3 content of 2.6 to 3.5 wt%, 2 to 5 wt% of plaster lime-based crack reducing agent, 0.1 to 5 wt% of calcium sulfoaluminate, 0.001 to 0.01 wt% of surfactant, 0.01 to 0.05 wt% of plasticizer, 0.001 to 0.01 wt% of thickener, and 65 to 80 wt% of fine aggregate of 6 mm or less and a placement method using the same.

Description

TECHNICAL FIELD [0001] The present invention relates to a cement mortar composition for outdoor flooring,

TECHNICAL FIELD The present invention relates to a cement mortar composition for outdoor floors and a construction method using the same. More specifically, by using a cement mortar composition for outdoor floors containing ordinary Portland cement having a powder degree of 4,500-5,500 cm 2 / g and an SO ₃ content of 2.6-3.5% by weight, the curing time, cracking problem and expansion problem are improved To a cement mortar composition for outdoor flooring and a method of casting using the same.

Currently, concrete or mortar using Portland cement as a binder is applied to the floor construction of construction and civil engineering sites. In consideration of compressive strength, drying shrinkage and construction characteristics according to each site, concrete and mortar suitable for construction are selected and installed have.

Concrete is more economical than mortar, has high compressive strength and durability and is mainly applied to the structure. Mortar is mixed with various additives such as fluidizing agent and crack reducing agent to reduce the drying shrinkage, It is mainly used for non-structural purposes such as indoor flooring.

The types of cement mortar currently used include ordinary mortar mixed with water and a composition in which cement and sand are mixed at a weight ratio of 1: 2 to 1: 5, but the cracks due to excessive drying shrinkage are greatly increased And the durability is greatly reduced. In order to compensate for this, floor cement mortar with additional crack reducing agent is used, but it has a problem of causing excessive expansion during continuous inflow of water, and thus it is used as an indoor floor mortar which does not have a possibility of water inflow after a certain time to be.

Therefore, there is no floor mortar that can be used outdoors due to the problem of cracking due to excessive drying shrinkage of ordinary mortar and the problem of floor mortar where excessive expansion is likely to be caused by continuous inflow of water. Therefore, Concrete is put in.

However, concrete is inevitable to be installed by using a pump car or a tower crane in a general construction site. Even if such an operation problem of concrete construction equipment occurs, there is no alternative but concrete. Therefore, an alternative to concrete is needed.

An object of the present invention is to solve the above problems and to provide a cement mortar composition for outdoor floors which can drastically improve the problem of serious cracking due to a delay in the finishing time, And a pouring method using the same.

Another object of the present invention is to provide a cement mortar composition for outdoor flooring which can overcome the problem of excessive expansion of a bottom mortar composition mixed with a crack-reducing material or an expanding material, and a method of casting using the same.

TECHNICAL FIELD The present invention relates to a cement mortar composition for outdoor floors and a construction method using the same.

The cement mortar composition for outdoor flooring of the present invention comprises 15-30 wt% of ordinary portland cement having a powder degree of 4,500-5,500 cm 2 / g and an SO ₃ content of 2.6-3.5 wt%, a gypsum lime accounting crack reducing material 2-5 wt% 0.1 to 5% by weight of calcium sulfoaluminate, 0.001 to 0.01% by weight of a surfactant, 0.01 to 0.05% by weight of a fluidizing agent, 0.001 to 0.01% by weight of a thickener and 65 to 80% by weight of a fine aggregate of 6 mm or less.

In the casting method using the cement mortar composition of the present invention,

(a) 15-30 wt% of ordinary Portland cement having a powder degree of 4,500-5,500 cm 2 / g and an SO ₃ content of 2.6-3.5 wt%, 2-5 wt% of a gypsum lime accounting crack reducing agent, Based on 100 parts by weight of a cement mortar composition comprising 5% by weight of a surfactant, 0.001 to 0.01% by weight of a surfactant, 0.01 to 0.05% by weight of a fluidizing agent, 0.001 to 0.01% by weight of a thickener and 65 to 80% To 20 parts by weight, and mixing the mixture, and

(b) placing and curing the floor after the mixing step

.

Hereinafter, the cement mortar composition for outdoor floors of the present invention will be described in detail.

The cement mortar composition for outdoor floor according to the present invention comprises 15-30 wt% of ordinary Portland cement having a powder degree of 4,500-5,500 cm 2 / g and an SO ₃ content of 2.6-3.5%, 2-5 wt% of gypsum lime accounting crack- 0.1 to 5% by weight of calcium sulfoaluminate, 0.001 to 0.01% by weight of a surfactant, 0.01 to 0.05% by weight of a fluidizing agent, 0.001 to 0.01% by weight of a thickener and 65 to 80% by weight of a fine aggregate of 6 mm or less.

(3,000 to 4,000 cm 2 / g) and SO ₃ (2.0 to 2.5 cm ₃ / g) by using ordinary Portland cement containing a powder of 4,500 to 5,500 cm 2 / g and an SO ₃ content of 2.6 to 3.5% Weight%) of cement can be shortened and the initial strength can be further improved. If the content of SO ₃ is less than 2.6% by weight, the initial coagulation time may be delayed and the plaster finishing time may be increased. If the content is more than 3.5% by weight, plaster finishing due to shortening of the coagulation time may be impossible It is preferable that the above-mentioned range is included. Further, it is characterized in that the initial strength can be improved by satisfying the above range of the degree of powder.

The content of the ordinary Portland cement containing the powder of 4,500-5,500 ㎠ / g and the SO ₃ content of 2.6-3.5% by weight is proper cement amount for piling on the roof of the top of the apartment house, To 15% by weight to 30% by weight of the mortar composition.

The gypsum finishing crack reducing agent of the present invention is used for suppressing the occurrence of cracks due to early / middle shrinkage by compensating expansion of plastic shrinkage caused by initial shrinkage and drying shrinkage at the initial shrinkage. The gypsum gypsum crack reducing material may be, for example, any one or a mixture of two or more selected from the group consisting of limestone, coke, quicklime and anhydrous gypsum, but is not necessarily limited thereto. Preferably 30 to 50% by weight of limestone and 50 to 70% by weight of cokes at a temperature of 800 to 900 DEG C, or 30 to 50% by weight of calcined lime and 50 to 70% by weight of anhydrous gypsum It is preferable to use the resulting mixture because heat generation due to plastic shrinkage and drying shrinkage can be suppressed. The anhydrous gypsum is effective in improving the initial strength and drying shrinkage reduction, and the quicklime can contribute to a shortening effect of condensation due to exothermic reaction and a drying shrinkage compensation effect due to expansion. The content of the gypsum finishing crack-reducing material is preferably 2 to 5% by weight in order to achieve a crack prevention effect. When the content is less than 2% by weight, cracks due to early and middle drying shrinkage compensation effect If the amount exceeds 5% by weight, it may cause a cracking problem due to late and expansion upon continuous inflow of water from the outside after curing, so that it is preferable to satisfy the above range.

The calcium sulfoaluminate of the present invention is used for shrinkage compensation and has an advantage in that initial sintering shrinkage due to an excessive water ratio of the mortar itself can be reduced by using calcium sulfoaluminate having a powder degree of 2,000 to 5,000 cm2 / . Also, the calcium sulfoaluminate has a particle size of 2,000 ~ 5,000 ㎠ / g and contains 3CaO · 3Al ₂ O ₃ · CaSO _4, and contains anhydrous gypsum (CaSO ₄ ) and calcium oxide . In the calcium sulfoaluminate, when the hydration reaction proceeds with the presence of gypsum, etch ringite (3CaO · 3Al ₂ O ₃ · 3CaSO ₄ · 32H ₂ O) is formed and grown on the surface of the particles. So that an expansion force can be imparted. The content of the calcium sulfoaluminate is preferably 0.1 to 5% by weight in order to improve workability and cracking due to over-expansion. Particularly when the content of the calcium sulfoaluminate exceeds 5% by weight, It is preferable to satisfy the above-mentioned range because the expansion of the accounting expandable material has a problem of occurrence of crack due to over expansion.

The surfactant of the present invention improves the material separation resistance, workability, freeze-thaw durability and the like by acting air in the cement mortar. By lowering the surface tension of the pore water in the cement mortar, the stress caused by the drying of the capillary water decreases To reduce drying shrinkage. Further, by forming a continuous air layer having a size of several micrometers, the drying speed of the mortar is increased and the stress generated in the cement mortar is absorbed in the air layer, thereby enhancing the resistance to cracking. Examples of the surfactant include, but are not limited to, olefin sulfonate anionic surfactants, alkyl ether anionic surfactants, sodium hydroxystearate, alkyl benzene sulfonic acid, lauryl sulfate, alkanesulfonate, poly One or two or more selected from the group of oxyethylene alkyl (phenyl) ether, polyoxyethylene alkyl (phenyl) ether sulfate or its salt, alkenylsulfosuccinic acid and imidazoline betaine may be mixed and used. It can include everything. The content of the surfactant is preferably 0.001 to 0.01% by weight for improving the durability and the compressive strength of the mortar. When the content is less than 0.001% by weight, the effect of improving the durability is insignificant, , The compressive strength of the mortar decreases to a larger value as the excess air entraining amount increases. Therefore, it is most preferable that the above range is satisfied.

The fluidizing agent of the present invention has an effect of increasing the fluidity of the cement mortar composition and reducing the water mixing amount while maintaining workability. The effect of reducing the amount of water mixing reduces the pore volume in the cement mortar, so that it has the additional effect of improving the strength and reducing the shrinkage due to drying. The fluidizing agent is preferably used for improving the workability for the construction of a specific place such as a rooftop of a multi-storey house where the length of the pipe is very long when pouring. The fluidizing agent is not limited, but specifically, for example, one or more selected from the group consisting of polycarboxylic acid type, lignin sulfonate type, polynaphthalene sulfonate type and polymelamine sulfonate type can be used , But it is not necessarily limited thereto. The content of the fluidizing agent is preferably 0.01 to 0.05% by weight for improvement of flowability and stability of bleeding and separation of materials. When the content of the fluidizing agent is less than 0.01% by weight, If it exceeds 0.05% by weight, there is a fear of increase in bleeding and occurrence of material separation, and it is preferable to satisfy the above range.

The thickener of the present invention is used for material separation stability of the composition. Examples of the thickening agent include, but are not limited to, nonionic cellulose ethers such as methylcellulose, ethylcellulose, hydroxymethylcellulose, hydroxyethylcellulose, carboxymethylcellulose, hydroxypropylcellulose, and polysaccharides Soluble water-soluble polymer, and preferably a methylcellulose thickener suitable for maintaining the material separation stability without impairing the workability can be used. The content of the thickening agent is preferably 0.001 to 0.01% by weight in order to improve the material separation stability and workability. When the content is less than 0.001% by weight, the effect of preventing the material separation is insignificant, , The viscosity of the cement mortar becomes excessively high and the workability is deteriorated, so that it is preferable to satisfy the above range.

The fine aggregate of 6 mm or less in the present invention may use any one or more of aggregates selected from a ladle having a particle size of 6 mm or less, preferably 0.01 to 6 mm, a cleaner, or a crushed aggregate. The content thereof is preferably 65 to 80% by weight for the strength and durability of the cement mortar composition for outdoor flooring.

When the cement mortar composition for outdoor flooring according to the present invention is used in combination in the above-mentioned range, cracking and durability deterioration due to excessive shrinkage of existing flooring cement mortar are drastically improved, It is characterized by the effect of improving the property.

Hereinafter, a concrete installation method using the cement mortar composition of the present invention will be described in detail.

In the casting method using the cement mortar composition of the present invention,

(a) 15-30 wt% of ordinary Portland cement having a powder degree of 4,500-5,500 cm 2 / g and an SO ₃ content of 2.6-3.5 wt%, 2-5 wt% of a gypsum lime accounting crack reducing agent, Based on 100 parts by weight of a cement mortar composition comprising 5% by weight of a surfactant, 0.001 to 0.01% by weight of a surfactant, 0.01 to 0.05% by weight of a fluidizing agent, 0.001 to 0.01% by weight of a thickener and 65 to 80% To 20 parts by weight, and mixing the mixture, and

(b) placing and curing the floor after the mixing step

.

After step (a), the step (a-1) may further include the step of providing an isolation joint having a thickness of 5 to 20 mm on a wall surface or a column of a structure to be installed, There is an advantage in that shrinkage expansion of the laid mortar can be controlled. The separating and bonding material may be formed of a material using a styrofoam or a resin component, but the present invention is not limited thereto. However, the present invention is not limited to this, and the separating joint material can be attached to the wall surface from the ground to the maximum height in consideration of the height of the mortar casting on the wall surface.

The step (b-1) may further include a step of saw cutting after the step (b), wherein the gap and the depth of the saw cutting are not limited, 0.1 to 3 mm and a depth of 0.1 to 6 mm is preferable because cracking can be minimized.

The present invention provides a cement mortar composition capable of replacing concrete that is applied to an outdoor floor, and a concrete construction method using the cement mortar composition. Accordingly, it is possible to select a composition of concrete or cement mortar according to the condition of a construction company, By making it possible to respond positively to changes in construction conditions, it is possible to improve the quality of construction or shorten the construction time due to construction work.

In addition, when the outdoor cement mortar composition of the present invention is used, it is possible to improve the cracking problem, improve the durability, prevent material separation and improve the workability.

FIG. 1 is a cross-sectional view of a wall part where an isolation joint is provided on the wall surface of the structure of the present invention.
FIG. 2 is a cross-sectional view of a pillar portion provided with an isolation joint at the pillar portion of the structure of the present invention.

Hereinafter, the present invention will be described in more detail by way of examples, but the present invention is not limited to the following examples.

The following physical properties were measured by the following methods.

The mortar in the following examples and comparative examples were mixed for 1 minute according to the mechanical mixing method of hydraulic cement paste and mortar of KS L 5109 and the water mixture amount was adjusted so that the flow value was about 200 ± 10 mm The flow rate was measured at 15 minutes after the bombing, and the degradation of the workability over time was also examined. The flow measurement of the mixture was performed by filling the flow cone using a flow cone having an upper diameter of 70 mm, a lower diameter of 100 mm, and a height of 50 mm specified in KS L 5111 and lifting the flow cone without compaction to measure the flow .

The concrete in the comparative example was mixed according to the ready mixed concrete production method of KS F 4009 and the slump was measured according to the concrete slump test method of KS F 2402.

The air content of the mortar mixture was measured using a mortar air gauge, and the air content of the concrete was measured using a concrete air mass analyzer according to the method of KS F 2421 pressure method. Curing time of mortar and concrete was measured according to KS F 2436 concrete immersion time test method.

The amount of bleeding of the non-beam mixture of the mortar was measured after filling the 700 ml of the mixture in a 1,000 ml measuring cylinder and standing for 3 hours, and the bleeding of the concrete was measured according to the bleeding test method of KS F 2414 concrete.

In order to examine the plastic shrinkage and shrinkage of cement mortar and concrete, the length change measurement was made by inserting a loop which can fix the mortar on one end of the length inside the frame of width × length × height = 100 × 1,000 × 50 mm And a mortar of the following examples and comparative examples was placed in a device for measuring the rate of change of the measurement connected to a 1 / 1,000 mm resolution gauge with a resolution of 20 ± 2 ° C and a humidity of 65 ± 5 % Curing conditions were measured for 28 days.

The compressive strength of the cement mortar was filled with bimetal mortar in a mold of 40 × 40 × 160 mm under the above curing conditions, and was demolded at a temperature of 20 ± 2 ° C. and a saturated humidity for 24 hours, And humidity of 65 ± 5% for 28 days. The compressive strength of concrete was measured according to the compressive strength test method of KS F 2405 concrete.

The resistance to freezing and thawing of mortar and concrete was carried out according to the resistance test method of concrete for rapid freezing and thawing of KS F 2456 and the relative dynamic modulus after completion of 300 cycles with 1 cycle of 4 ~ And the durability index was obtained.

On the other hand, a mock-up test was conducted to confirm whether or not cracks were generated. The members were manufactured in a size of width × length × height = 1,000 × 1,000 × 100 mm, cured for 28 days in the curing condition, Respectively. Also, the cement mortar for outdoor flooring was installed on the actual construction site, and cracks were observed for 6 months.

[Example 1]

First step

100 kg of one kind of ordinary Portland cement having a chemical composition ratio of 4,800 cm 2 / g as shown in Table 1 below, 14.3 kg of gypsum lime accounting crack reduction material, 8.2 kg of calcium sulfoaluminate (CSA) , 0.004 kg of an olefin sulfonate anionic surfactant and 0.012 kg of a methylcellulose thickener were added to a powder mixer and mixed for 1 minute to prepare a compound composition,

[Table 1] Chemical composition ratio (% by weight)

Second Step

To the composition prepared in the first step, 287 kg of sand having a particle size of 6 mm or less was put into a mixer and homogeneously mixed for 1 minute to prepare a cement mortar composition for outdoor flooring.

[Example 2]

First step

100 kg of one kind of ordinary Portland cement having the chemical composition ratio of the above Table 1, 9.8 kg of gypsum lime accounting crack reducing material, 7.8 kg of calcium sulfoaluminate (CSA), a polycarboxylic acid-based fluidizing agent , 0.004 kg of an olefin sulfonate anionic surfactant and 0.012 kg of a methylcellulose thickener were added to a powder mixer and mixed for 1 minute to prepare a compound composition,

Second Step

276 kg of sand having a particle size of 6 mm or less was put into a mixer and homogeneously mixed for 1 minute to prepare a cement mortar composition for outdoor flooring.

[Example 3]

First step

100 kg of one kind of ordinary Portland cement having a chemical composition ratio of 4,800 cm 2 / g as shown in Table 1, 14.3 kg of gypsum lime accounting crack reduction material, 8.2 kg of calcium sulfoaluminate (CSA) 0.008 kg of an olefin sulfonate anionic surfactant and 0.008 kg of a methylcellulose thickener were added to a powder mixer and mixed for 1 minute to prepare a compound composition,

Second Step

To the composition prepared in the first step, 287 kg of sand having a particle size of 6 mm or less was put into a mixer and homogeneously mixed for 1 minute to prepare a cement mortar composition for outdoor flooring.

[Example 4]

First step

100 kg of one kind of ordinary Portland cement having a powder composition of 4,800 cm 2 / g and the chemical composition ratio shown in Table 2, 14.3 kg of gypsum lime accounting crack reduction material, 8.2 kg of calcium sulfoaluminate (CSA) , 0.004 kg of an olefin sulfonate anionic surfactant and 0.012 kg of a methylcellulose thickener were added to a powder mixer and mixed for 1 minute to prepare a compound composition,

[Table 2] Chemical composition ratio (% by weight)

Second Step

To the composition prepared in the first step, 287 kg of sand having a particle size of 6 mm or less was put into a mixer and homogeneously mixed for 1 minute to prepare a cement mortar composition for outdoor flooring.

[Example 5]

First step

100 kg of one kind of ordinary Portland cement having a powder composition of 4,800 cm 2 / g and the chemical composition ratio shown in Table 3 below, 14.3 kg of gypsum lime accounting crack reduction material, 8.2 kg of calcium sulfoaluminate (CSA) , 0.004 kg of an olefin sulfonate anionic surfactant and 0.012 kg of a methylcellulose thickener were added to a powder mixer and mixed for 1 minute to prepare a compound composition,

[Table 3] Chemical composition ratio (% by weight)

Second Step

To the composition prepared in the first step, 287 kg of sand having a particle size of 6 mm or less was put into a mixer and homogeneously mixed for 1 minute to prepare a cement mortar composition for outdoor flooring.

[Comparative Example 1]

100 kg of one kind of common portland cement having a chemical composition ratio of 4,800 ㎠ / g of powder and 300 kg of sand having a particle size of 6 mm or less were put into a mixer and homogeneously mixed for 1 minute to prepare a cement mortar composition .

[Comparative Example 2]

First step

100 kg of one kind of ordinary Portland cement having the chemical composition ratio shown in Table 1, 16.3 kg of gypsum lime accounting crack reduction material and 9.3 kg of calcium sulfoaluminate (CSA) having a powder degree of 4,800 cm 2 / g were put into a powder mixer, For 1 minute to prepare a compound composition,

Second Step

340 kg of sand having a particle size of 6 mm or less was put into a mixer and homogeneously mixed for 1 minute to prepare a cement mortar composition for outdoor flooring.

[Comparative Example 3]

First step

100 kg of one kind of ordinary Portland cement having the chemical composition ratio shown in Table 1, 16.3 kg of gypsum lime accounting crack reduction material, 9.3 kg of calcium sulfoaluminate (CSA), a polycarboxylic acid-based fluidizing agent 0.14 kg were put into a powder mixer and mixed for 1 minute to prepare a compound composition,

Second Step

340 kg of sand having a particle size of 6 mm or less was put into a mixer and homogeneously mixed for 1 minute to prepare a cement mortar composition for outdoor flooring.

[Comparative Example 4]

First step

100 kg of one kind of ordinary Portland cement having a chemical composition ratio of 4,800 cm 2 / g as shown in Table 4, 16.3 kg of gypsum lime accounting crack reducing material and 9.3 kg of calcium sulfoaluminate (CSA) were put into a powder mixer, For 1 minute to prepare a compound composition,

[Table 4] Chemical composition ratio (% by weight)

Second Step

340 kg of sand having a particle size of 6 mm or less was put into a mixer and homogeneously mixed for 1 minute to prepare a cement mortar composition for outdoor flooring.

[Comparative Example 5]

First step

100 kg of one kind of ordinary Portland cement having a chemical composition ratio of 4,800 cm 2 / g in powdery degree, 16.3 kg of gypsum lime accounting crack reducing material and 9.3 kg of calcium sulfoaluminate (CSA) were put into a powder mixer, For 1 minute to prepare a compound composition,

[Table 5] Chemical composition ratio (% by weight)

Second Step

To the composition prepared in the first step, 287 kg of sand having a particle size of 6 mm or less was put into a mixer and homogeneously mixed for 1 minute to prepare a cement mortar composition for outdoor flooring.

[Comparative Example 6]

First step

100 kg of one kind of ordinary Portland cement having a chemical composition ratio of 4,800 cm 2 / g as shown in Table 4, 14.3 kg of gypsum lime accounting crack reduction material, 8.2 kg of calcium sulfoaluminate (CSA) , 0.004 kg of an olefin sulfonate anionic surfactant and 0.012 kg of a methylcellulose thickener were added to a powder mixer and mixed for 1 minute to prepare a compound composition,

Second Step

To the composition prepared in the first step, 287 kg of sand having a particle size of 6 mm or less was put into a mixer and homogeneously mixed for 1 minute to prepare a cement mortar composition for outdoor flooring.

[Comparative Example 7]

First step

100 kg of one kind of ordinary Portland cement having the chemical composition ratio shown in Table 5, 14.3 kg of gypsum lime accounting crack reduction material, 8.2 kg of calcium sulfoaluminate (CSA), a polycarboxylic acid-based fluidizing agent , 0.004 kg of an olefin sulfonate anionic surfactant and 0.012 kg of a methylcellulose thickener were added to a powder mixer and mixed for 1 minute to prepare a compound composition,

Second Step

To the composition prepared in the first step, 287 kg of sand having a particle size of 6 mm or less was put into a mixer and homogeneously mixed for 1 minute to prepare a cement mortar composition for outdoor flooring.

[Comparative Example 8]

(Standard granular material AE) 168 kg, fly ash 39 kg, slag 52 kg, sand (granulation rate 2.75) 652 kg, crushed sand (granulation rate 2.93) 283 kg, aggregate (25 mm crushed aggregate) 923 kg, Water reducing agent) (2.02 kg) and water (161 kg) were put into an omni mixer and mixed to prepare a concrete composition.

[Table 6] Formulation of cement mortar composition

[Table 7] Concrete composition (content is kg) Specification 25-18-80

[Table 8] Properties of cement mortar composition and concrete prepared by mixing water

[Table 9] Properties of cement mortar composition and concrete prepared by mixing water

 When the physical properties of the cement mortar composition prepared by varying the addition ranges of the levels of Examples 1 to 5 according to the present invention were not mixed with the constituent materials of the respective admixtures of Comparative Examples 1 to 5 As a result,

Compared with Comparative Example 1, which is a general mortar generally used in the field without using a crack reducing agent and an expanding agent, Examples 1 to 5 showed that the shrinkage length change rate was as low as 1/5, And the compressive strength is also high.

Comparative Examples 2 to 3, in which a crack reducing agent or a fluidizing agent is used in some cases, are generally used for indoor flooring. However, in order to obtain the same workability as in Examples 1 to 5, the amount of water added is high and the bleeding rate is high, And the compressive strength is low. In addition, in the case of Comparative Examples 2 to 3, even though the crack reducing agent or the fluidizing agent was mixed into the present invention, the freeze-thaw resistance (relative dynamic elasticity modulus) was very low as the surfactant was not used.

In the case of Comparative Examples 4 to 7 in which the SO ₃ content in the cement was 2.6 or less or 3.5 or more, the setting time was 10 to 15% faster or slower than those in Examples 1 to 5, Or slowed down.

Compared with Comparative Example 8, which is generally used concrete, Examples 1 to 5 have a length change rate of 1/5 level, which is low, and cracks are not generated at all, and the compressive strength is also high.

Example 1 was applied to an actual construction site and as a result, cracks did not occur at all during 6 months of age.

Therefore, a cement mortar composition which can be applied to outdoor floors should be composed of a composition in which the respective constituent materials are combined as shown in the above Examples 1 to 5, and must be maintained at the level of addition specified in the present invention.

10: Isolation joint
20: Mortar
30: Structure

Claims (10)

15-30 wt% of ordinary portland cement having a powder degree of 4,500-5,500 cm 2 / g and an SO ₃ content of 2.6-3.5 wt%, 2-5 wt% of gypsum lime accounting crack reducing agent, 0.1-5 wt% of calcium sulfoaluminate, 0.001 to 0.01% by weight of a surfactant, 0.01 to 0.05% by weight of a fluidizing agent, 0.001 to 0.01% by weight of a thickener, and 65 to 80% by weight of a fine aggregate of 6 mm or less. The method according to claim 1,
The cement mortar composition for outdoor floors as claimed in claim 1, wherein the gypsum-based crack reducing agent is one or a mixture of two or more selected from the group consisting of limestone, coke, quicklime and anhydrous gypsum. The method according to claim 1,
Wherein the calcium sulfoaluminate has a powder viscosity of 2,000 to 5,000 cm2 / g and contains anhydrous gypsum (CaSO4) and calcium oxide (CaO). The method according to claim 1,
The surfactant may be at least one selected from the group consisting of an olefin sulfonate anionic surfactant, an alkyl ether anionic surfactant, sodium hydroxystearate, alkylbenzenesulfonic acid, lauryl sulfate, alkanesulfonate, polyoxyethylene alkyl (phenyl) ether, polyoxyethylene Alkyl (phenyl) ether sulfuric acid ester or a salt thereof, alkenylsulfosuccinic acid and imidazoline betaine are used as the cement mortar composition for outdoor flooring. The method according to claim 1,
Wherein the fluidizing agent is one or more selected from the group consisting of polycarboxylic acid type, lignin sulfonate type, polynaphthalene sulfonate type, and polymelamine sulfonate type. The method according to claim 1,
Wherein the thickener is one or more selected from the group consisting of nonionic cellulose ethers and polysaccharide water-soluble polymer compounds. The method according to claim 6,
Wherein the thickener of the nonionic cellulose ethers is selected from the group of methylcellulose, ethylcellulose, hydroxymethylcellulose, hydroxyethylcellulose, carboxymethylcellulose, and hydroxypropylcellulose. (a) 15-30 wt% of ordinary Portland cement having a powder degree of 4,500-5,500 cm 2 / g and an SO ₃ content of 2.6-3.5 wt%, 2-5 wt% of a gypsum lime accounting crack reducing agent, Based on 100 parts by weight of a cement mortar composition comprising 5% by weight of a surfactant, 0.001 to 0.01% by weight of a surfactant, 0.01 to 0.05% by weight of a fluidizing agent, 0.001 to 0.01% by weight of a thickener and 65 to 80% To 20 parts by weight, and mixing the mixture, and
(b) placing and curing the floor after the mixing step
A method of casting using a cement mortar composition. 9. The method of claim 8,
The method of (a) further comprises: (a-1) installing an isolation joint having a thickness of 5 to 20 mm on a wall surface of a structure to be laid, using a cement mortar composition. 9. The method of claim 8,
The method as set forth in claim 1, further comprising the step of (b-1) cutting the slab after the step (b) is performed, using the cement mortar composition.

Images