JPH04367552A - Maintenance for steam-cured lightweight cellular concrete material - Google Patents

Abstract

PURPOSE:To provide the title maintenance capable of giving the title cellular concrete which is of low shrinkage during drying and improved in high-early- strength developability, bond strength and durability, mainly comprising Portland cement, perlite and wollastonite. CONSTITUTION:The objective maintenance comprising (A) 35-60 pts.wt. of Portland cement as binder, (B) 40-60 pts.wt. of perlite as aggregate <=1mm in granular size and 1.0-0.6 in specific gravity and (C) 5-30 pts.wt. of wollastonite, and, in addition, (D) 1-5 pts.wt. of a water repellent and (E) 0.5-2.0 pts.wt. of a thickening agent.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a repair material used for repairing steam-cured lightweight cellular concrete (hereinafter referred to as ALC material).

0002

[Prior Art] ALC materials are made by mixing siliceous raw materials such as silica sand and silica stone, and calcareous raw materials such as lime and cement in an appropriate ratio with water, and then foaming metal powder such as aluminum. It is manufactured by adding a chemical agent and stirring to incorporate air bubbles, solidifying and hardening it, then transferring it to an autoclave and curing it in high-temperature, high-pressure steam.

[0003] The ALC material manufactured in this way has a large number of pores, so it has a low specific gravity and excellent heat insulation properties, and is easy to construct. However, it has the drawbacks of high water absorption and easy chipping. have. Therefore, the repair process was not approved at the ALC material production site or construction site in order to proceed to the next process.

[0004] Various repair materials for ALC materials have been developed and put into practical use.
Publication No. 1 (hereinafter referred to as 1st document) or Japanese Patent Application Laid-Open No. 1983
The technique disclosed in Japanese Patent No. 149863 (hereinafter referred to as the second document) is common.

That is, the repair material for ALC materials described in the first document is as follows.

14 to 80 parts by weight of Portland cement,
A composition comprising 16 to 84 parts by weight of ALC powder, 1 part by weight of methylcellulose, and 1 part by weight of potassium carbonate, and 33 to 40 parts by weight of water.

[0007] Furthermore, the composition of the repair material for ALC materials described in the second document is as follows.

15 to 90 parts by weight of Portland cement;
ALC powder 60 parts by weight or less, additives 0.5 to 1 part by weight,
A composition prepared by mixing predetermined amounts of a water repellent and perlite, and adding 20 to 70 parts by weight of water to the mixture.

Both of the above two conventional compositions use ALC powder, which absorbs a large amount of water, as an aggregate, so in order to ensure the softness that makes it easy to handle with a trowel during repair, it is necessary to mix water/solids. It was necessary to increase the ratio, which resulted in a decrease in strength (particularly in one-day strength), the occurrence of cracks, and an increase in shrinkage. For this reason, if a conventional repair material having the composition as described above is used for repair, there are problems such as cracks occurring in the repaired area or damage in extreme cases when the repair material is transported.

0010

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances. The purpose of this product is to develop strength quickly, to have a strength higher than that of ALC materials, to be able to be shipped within one day after repair, to have good adhesion to ALC materials, to have a low drying shrinkage rate, and to prevent the occurrence of cracks. The purpose is to propose a repair material for ALC materials that can reduce the amount of damage.

[0011]

[Means for Solving the Problems] The present invention is a repair material used for repairing ALC materials, which is made of a composition using Portland cement as a binder, and the aggregate is pearlite and wollastonite (wollastonite). A repair material for ALC material characterized by using the main material as the main material.

[0012] Portland cement that can be used as a binding material in this repair material is commercially available, and examples include white Portland cement, ordinary Portland cement, early strength Portland cement, and the like.

[0013] In this repair material, pearlite and wollastonite are used as aggregates without using ALC powder. As perlite, commercially available perlite can be used in powder form. Preferably, obsidian foam is used, with a particle size of 1 mm or less and a specific gravity of 1.0 to 1.0, in order to achieve physical properties similar to ALC materials.
It is preferable to combine particles with a particle size of about 0.6 mm and particles with a particle size of about 1 to 2 mm. As wollastonite, powder of acicular crystals is used. The needle-like shape is preferably one that allows 99% of the needle to pass through a 0.25 mm mesh.

[0014] In addition to the binder and aggregate described above, water repellents such as water repellents or thickeners may be added as necessary.
Like the other ingredients, any powder can be used. C12 to C20 metal soaps are preferred, such as calcium stearate, calcium oleate, and the like.

The preferred composition range of this repair material is 35 to 60 parts by weight of Portland cement and 40 to 60 parts by weight of pearlite.
parts by weight, 5 to 30 parts by weight of wollastonite, 1 to 5 parts by weight of water repellent, and 0.5 parts by weight of thickener (methyl cellulose powder).
~2.0 parts by weight, etc. are added. The proportion of wollastonite in the solid content is more preferably 5 to 30% by weight. If it is less than 5%, no significant effect will be obtained, and if it is more than 30%, the specific gravity will be too high and it will not be compatible with the ALC material, which is not preferable.

[0016]

[Effect] This repair material eliminates the use of ALC powder, which absorbs a large amount of water, and uses wollastonite as an aggregate, thereby reducing the water/solids ratio and ensuring a softness that is easy to work with. , the reinforcing effect of the acicular crystals of wollastonite is added, and a cured product with low shrinkage and high strength can be obtained. Furthermore, by using wollastonite in combination with pearlite having a low specific gravity, physical properties such as specific gravity become similar to those of ALC material, and the material has excellent strength.

[0017]

EXAMPLES Next, the present invention will be explained in more detail with reference to examples.

[0018]

[Example 1 and Comparative Example 1] White cement 4.3% by weight,
42.2% by weight of obsidian foam with a particle size of 1 mm or less, 0.48% by weight of obsidian foam with a particle size of 1 to 2 mm, wollastonite (
99% passed through 0.25mm mesh) 12.8
4% by weight of calcium stearate, 3.83% by weight of calcium stearate, and 0.34% by weight of methylcellulose, and 29% by weight of water was added and kneaded based on the weight of the solid mixture to obtain a repair material.

On the other hand, as a comparative example, a repair material was prepared having the same composition as the example except that wollastonite was not added and ALC powder was used instead.

[0020] Next, commercially available ALC materials were repaired using the repair material manufactured using the above formulation, and the bending strength, compressive strength, and drying shrinkage percentage after 1 day, 3 days, and 7 days of material age were determined, and the results were tabulated. Shown in 1.

[0021] Here, the bending strength and compressive strength were measured using a 4 x 4 x 16 cm specimen according to JIS, and the drying shrinkage rate was measured using a 4 x 4 x 16 cm specimen according to JIS in a formwork for 24 hours.
After curing for a period of time, the formwork was removed and the moving length of the opposite sides of the specimen was measured using a comparator.

[0022]

[Table 1]

[0023]

Effects of the Invention Since the repair material according to the present invention has the above-described structure and function, the ALC material such as a panel repaired with this repair material has a high adhesive strength between the ALC material and the repair material, and the repair material can be easily maintained after repair. It can be shipped within one day, and since the drying shrinkage rate is small, there is no risk of cracking or peeling. In particular, when used in cold regions, the repair material of the present invention with high strength and low shrinkage rate exhibits excellent performance in terms of durability.

Claims (1)

[Claims] Claim 1: A repair material used for repairing steam-cured lightweight cellular concrete, comprising a composition using portland cement as a binder, and whose aggregates are mainly pearlite and wollastonite. A repair material for steam-cured lightweight aerated concrete.