KR20010028967A - Composition of height powerfulness for nothing repair cement - Google Patents

Abstract

PURPOSE: A non-shrinking cement composition having high strength is provided which prevents a crack caused by drying and firing shrinkage. CONSTITUTION: The non-shrinking cement composition having high strength comprises: (i) 8-16 wt.% of HAN99 containing a cement expanding agent having 45-55% of anhydrous plaster, 10-20% of quicklime and 25-45% of CAS; (ii) more than 24-36 wt.% of cement; (iii) 53-64 wt.% of S1 sand for plastering mortar wherein, a particle size of S1 is less than 1 millimeter; (iv) 4-5 wt.% of fly ash; (v) less than 2 wt.% of calcium hydroxide; and (vi) 0.005 wt.% of methylcellulose.

Description

High Strength Anhydrous Cement Composition {COMPOSITION OF HEIGHT POWERFULNESS FOR NOTHING REPAIR CEMENT}

The present invention relates to a high strength non-contraction cement composition using a CAS-based expander (HAN99).

There are two types of plaster mortars currently in use, general plaster mortar and plaster mortar to be sprayed, but as the needs of consumers are diversified, the necessity of producing a specialized mortar for plastering is increasing.

Conventional cements have been developed to prevent cracking by further supplementing cement expansion agents to compensate for shrinkage that occurs during drying of cement compositions.

Korean Patent Publication No. 86-1644 describes free CaO 15 to 60 weight, free CaF ₂

5 to 30 parts by weight, 11CaO · 7Al ₂ O ₃ · relates to a cement expanding agent, characterized in that is configured as a clinker grinding water containing CaSO₄30 to 80 parts by weight and other elements 10 by weight or less,

Korean Patent Application Publication No. 91-9886 discloses a 3CaO · Al ₂ O _{3 4CaO · Al 2 O 3 · Fe} 2 O is not more than the total content of ₃ 10 parts by weight 60 to 75 parts by weight of 3CaO · SiO _2, Na ₂ O equivalent The thermosetting cement composition is composed of an alkali content of less than 0.2 wt% and the rest mainly containing 2CaOSiO ₂ and gypsum, and having a specific surface area of 3500 to 5500 cm 2 / g.

The cement expanders of the prior arts generally have a problem of lowering the strength of the cement hardened body since the hydration expansion tends to occur rapidly.

In order to solve the above problems, the present invention by applying the HAN99 (CAS expanding agent) manufactured by the company itself as an expansion material in order to prevent cracking due to drying and plastic shrinkage, which is a disadvantage of cement products, shrinkage does not occur during long-term age. It is an object of the present invention to provide a non-shrinkless mortar for high strength and non-shrinkable cement mortar that can be used for sites requiring high strength.

In order to achieve the above object, the present invention is HAN99 manufactured by the company itself as an expansion material containing anhydrous gypsum 45 ~ 55, quicklime 10 ~ 20, CAS-based 25 ~ 45 added to compensate for the drying and plastic shrinkage of cement The proper amount of is about 8 ~ 16wt of cement, which has a length change rate of +0.02 for one month in air condition.

In order to show high strength (more than 300㎏f / ㎠) in high strength non-shrink plastering mortar, cement use amount should be added more than 24 ~ 36wt.

Plaster mortar is 53 ~ 64wt S1 sand, fly ash 4 ~ 5wt, slaked lime 2wt or less, MC (methyl cellulose) 0.005wt, the size of S1 refers to the composition composed of 1mm or less.

Normally, HAN99 is composed of anhydrous gypsum 50, CAS 35 and CaO 15, and the present invention is composed of 4CaO.3Al ₂ O ₃ .CaSO 'mineral as a CAS system.

Example 1 (non-shrink plastering mortar)

It is an expansion material containing anhydrous gypsum 50, quicklime 15, and CAS-based 35 in general plaster mortar produced in mortar factory, and its own HAN99 was used. , 10, 12, 14wt was added to the experiment to change the length.

[Table below. 1] is the experimental mixture, [Table. 2] and [Figure.1] show the results of experiments with the rate of change of length depending on the amount of HAN99.

[table. 1] Experimental formulation

(Unit: wt)

Compounding classification CEMENT S₁ S₂ F / A LIME MC HAN99 Remarks One 25 65.8 5 4 0.2 0.005 - General Plaster Mortar 2 〃 63.8 〃 〃 〃 〃 2.0 HAN99 = C × 8 3 〃 63.3 〃 〃 〃 〃 2.5 HAN99 = C × 10 4 〃 62.8 〃 〃 〃 〃 3.0 HAN99 = C × 12 5 〃 62.3 〃 〃 〃 〃 3.5 HAN99 = C × 14

[table. 2] Length change rate test result

(unit : )

Remarks One 2 3 4 5 2 days underwater -0.0010 0.0163 0.0215 0.0274 0.0411 4 days underwater -0.0046 0.0140 0.0268 0.0368 0.0474 7 days underwater -0.0001 0.0152 0.0295 0.0498 0.0724 7 days -0.0313 -0.0013 0.0128 0.0304 0.0561 1 month -0.0756 -0.0352 -0.0258 0.0108 0.0152

[Drawing. 1] Length change rate according to HAN99 addition amount

Experiment of length change rate by adding 8, 10, 12, 14wt of cement amount to find the proper amount of shrinkage that does not occur by applying HAN99 manufactured by our company as an expansion material containing anhydrous gypsum 50, quicklime 15 and CAS system 35 As a result, the addition of 14wt of cement amount is in the expansion state, not shrinkage, with the rate of change of length +0.015 after one month, and it is considered that the proper amount of use is 12-14wt.

Example 2 (high strength non-shrink plastering mortar)

Compressive strength of general plastering mortar (age 28 days) shows about 160-210kgf / ㎠, but as consumer needs are diversified and the places where the site requires high strength increases, compressive strength 300 days In order to express more than ㎏f / ㎠, the experiment was carried out while increasing the amount of cement to 28, 30, 32, 34 wt. The experiment was added.

[Table below. 3] is the experimental compounding ratio, [Table. 4] and [Figure. 2] [Figure. 3] shows the results of compressive strength and length change rate according to the amount of cement added.

[table. 3] experimental formulation

(Unit: wt)

division CEMENT S₁ S₂ F / A LIME MC HAN99 Remarks One 28 63.44 - 5 0.2 0.005 3.36 HAN99 = C × 14 2 30 61.20 - 〃 〃 〃 3.60 HAN99 = C × 14 3 32 58.96 - 〃 〃 〃 3.84 HAN99 = C × 14 4 34 56.72 - 〃 〃 〃 4.08 HAN99 = C × 14

Table 4. Experimental Results

division One 2 3 4 Remarks Compressive strength (㎏ / ㎠) 3 days 161 185 213 262 7 days 220 248 286 297 28 days 268 298 336 364 Length change rate () 2 days underwater 0.0317 0.0392 0.0453 0.0433 4 days underwater 0.0444 0.0576 0.0653 0.0642 7 days underwater 0.0570 0.0747 0.0914 0.0930 7 days 0.0267 0.0442 0.0640 0.0535 1 month 0.0065 0.0146 0.0295 0.0302

[Drawing. 2] Compressive strength according to the amount of cement added

[Drawing. 3] Length change rate according to the amount of cement added

HAN99 was fixed at 14wt of cement and the cement content was increased to 28, 30,32,34wt. As the length change rate increases (expansion), it is found that a suitable cement amount of high strength non-contraction mortar is 32 to 34 wt%.

Example 3 (high strength non-contraction cement mortar)

Based on the experimental results in 2.1 and 2.2 above, a comprehensive experiment was carried out for the non-cemented plastering mortar and the high-strength non-cemented plastering mortar. 5] [Table. 6].

[table. 5] Experimental formulation

Unit: wt

division CEMENT S₁ S₂ F / A LIME MC HAN99 Remarks Anhydrous mortar 25 62.3 5 4 0.2 0.005 3.50 HAN99 = C × 14 High strength non-shrink mortar 32 58.32 - 5 〃 〃 4.48 HAN99 = C × 14

[table. 6] Experiment result

Test Items Anhydrous mortar High strength non-shrink mortar W / R () 18.3 19.0 Unit weight (㎏ / ㎥) 1900 1987 Air volume () 12.0 8.6 B / D (㎏ / ㎥) 1500 1394 importance 2.72 2.56 Conservability 78 79 Setting time First minute 420 320 Termination (time) 11:15 7:40 Absorption rate () 9.21 9.04 Adhesive strength (㎏f / ㎠) 4.8 5.7 Compressive strength (㎏f / ㎠) 3 days 118 210 7 days 174 272 28 days 224 330 Length change () 7 days underwater 0.0804 0.0914 7 days 0.0362 0.0440 1 month 0.0133 0.0212

Experimental results for the non-contraction plaster mortar and high strength non-contraction plaster mortar is as follows.

First, the appropriate amount of HAN99 manufactured by the company is an expanded material containing anhydrous gypsum 50, quicklime 15, and CAS-based 35 added to compensate for drying and plastic shrinkage of cement. It is about 14wt of cement with expansion of +0.02.

Second, in order to show high strength (more than 300㎏f / ㎠) in high strength non-shrink plastering mortar, the amount of cement used must be added more than 32wt.

The present invention as described above is to prevent cracking due to drying and plastic shrinkage as a high-strength non-contraction plaster mortar, there is an effect that hardly shrinkage during long-term age.

Claims (2)

In the cement composition, Self-manufactured HAN99 containing anhydrous gypsum 45 ~ 55, quicklime 10 ~ 20, and CAS 25 ~ 45 as cement swelling agent is added about 8 ~ 16wt of cement amount and about 24 ~ 36wt of cement. S1 sand 53 ~ 64wt, fly ash 4 ~ 5wt, calcined lime 2wt or less, MC (methyl cellulose) 0.005wt, high strength non-contraction cement composition characterized in that the size of S1 is 1mm or less. According to claim 1, about 14wt of cement content and about 32wt or more of cement, HAN99, which contains anhydrous gypsum 50, quicklime 15, and CAS system 35, is added as a cement swelling agent. 60wt, fly ash 4 ~ 5wt, calcined lime 0.2wt, MC (methylcellulose) 0.005wt, the size of S1 is 0.8mm or less composition, characterized in that the high strength non-contraction cement composition.