JPS62207744A - High strength mortar concrete - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is characterized in that high-strength aggregate and spherical aggregate are used as aggregate components in a cementitious material and ultrafine powder-based hydraulic composition. Regarding high strength mortar concrete.

[Prior art]

Traditionally, methods to improve the strength of mortar and concrete include minimizing the amount of water used, such as lowering the (water/cement) ratio by using a water reducing agent, or using curing methods such as underwater or steam curing. Alternatively, 1. selection of cementitious materials has been carried out.

However, there are limits to the selection of cementitious materials;
Curing in water or steam is difficult for large mortar and concrete moldings. Furthermore, in the method of reducing the (water/cement) ratio, fluidity is reduced at the same time, impairing workability. In order to solve this type of problem, it has been proposed to incorporate water reducing agents and ultrafine powder into cementitious materials (for example,
863@). This makes it possible to lower the (water/cement) ratio without significantly reducing workability, but attempting to achieve an even lower (water/cement) ratio may result in loss of fluidity or difficulty in mixing. There is a drawback that it becomes.

[Problem that the invention seeks to solve]

The present inventors have solved the problem of obtaining high-strength mortar concrete with a low (water/cement) ratio without losing strength.
As a result of various studies on methods for improving fluidity, it was discovered that adding spherical aggregates to commonly used high-strength aggregates has a significant effect, leading to the completion of the present invention.

[Means for solving the invention]

To summarize the invention, a high-strength mortar concrete comprising a cementitious material, an ultrafine powder, a water reducing agent, water, and an aggregate is characterized in that the aggregate is comprised of a high-strength aggregate and a spherical aggregate. It is related to.

Hereinafter, the configuration of the present invention will be explained in detail.

First, in the present invention, aggregate components that greatly contribute to improving workability and fluidity with a low (water/cement) ratio,
That is, the aggregate component composed of high-strength aggregate and spherical aggregate will be explained.

The high-strength aggregate referred to in the present invention is one that is harder than that used for ordinary mortar concrete, and in order to obtain high-strength mortar concrete, it is necessary to have a Mohs hardness of 6.
Above, the Knoop indenter hardness is 700! J/rat or more is preferred. Examples of materials that meet this standard include silica, emery, magnetic steel, magnetic steel, yellow jade, lawsonite, zircon, calcined bauxite, heavy burnt shale, boron carbide, tungsten carbide, alumina, fused silica, and silicon carbide. , crushed ceramics, etc. Furthermore, high-strength mortar concrete can also be obtained using metal materials such as iron and stainless steel. These high-strength aggregates may be natural or artificial, but they are somewhat difficult to obtain when considering adhesion with cementitious substances (binding materials), economic efficiency (price), and stability of supply. Artificial aggregates with a burr shape are preferred. In general, the shape of high-strength aggregate is irregular, angular, granular, dendritic, acicular, spongy, or flaky, and its shape is significantly different from the spherical aggregate described below. ing.

Moreover, spherical aggregate is usually obtained by melting metal or ceramic and then blowing it away with atmospheric pressure and cooling it, and it is preferable that there is not a large difference in specific gravity from the above-mentioned high-strength hard aggregate. The shape of the aggregate is rounded or spherical, and although there are no restrictions regarding the composition of the aggregate, it is preferable that the aggregate be of high strength.

Examples of this type of spherical aggregate include quenched converter slag and blast furnace slag (cooled by air, also called air crushing), iron balls, stainless steel balls, glass balls, and ceramic balls such as alumina and zircon mullite. be. In particular, preferred materials with high strength include rapidly cooled converter slag, metal balls, and ceramic balls.

The above-mentioned aggregate components generally have a particle size of 100 μm or more, but from the viewpoint of incorporating a large amount without impairing fluidity, the particle size is usually 0.1 to 1 μm.
．． 0. It is preferable to have a particle size of .

In the aggregate made of the high-strength aggregate and spherical aggregate, when the blending ratio of the spherical aggregate is 0.05 to 0.1 (volume ratio), fluidity is improved at a low (water/cement) ratio. If it exceeds 0.7 (capacity ratio), the adhesion with the binder will decrease, so the compressive strength will be 1008. It is not preferable to obtain a mortar concrete molded product having a value larger than about Pa, and if it is smaller than 0.05 (capacity ratio), no improvement in fluidity can be seen.

Next, other ingredients used in the present invention will be explained.

The cementitious materials used in the present invention include ordinary, early strength, ultra early strength, white or sulfate-resistant Portland cement, mixed cements such as blast furnace cement, fly ash cement, kneelite, and LD-3lag. Commonly used materials include kneelite made from carbon dioxide, a combination of blast furnace slag and stimulants, etc. Furthermore, it is possible to use a material in which a part of the cementitious material is replaced with an inert inorganic material or a metallic material having approximately the same particle size. It is also possible to compensate for shrinkage using expansive cement, to develop the required strength in a short time using rapid hardening cement, and to use a gypsum-based high-strength admixture.

These cementitious materials usually have a particle size of 10 to 30 μm, but it goes without saying that those with smaller or larger particle sizes can also be used. Generally, a material of about 10 to 20 μm is used.

In addition, compounding agents such as quick hardening agents, high-strength admixtures, and chemical admixtures that are normally used in cement concrete can also be used for these cementitious substances.

The ultrafine powder used in the present invention is one whose average particle size is at least one order of magnitude smaller than the cementitious material's average particle size of 10 to 30 μm, preferably two orders of magnitude smaller. The ultrafine powder improves the fluidity and workability of the mixture system of the cementitious material and aggregate components, fills the interparticle voids formed in the mixture system, creates a near-closest packing, and improves the strength of the hardened product. This is an essential ingredient to ensure that

Suitable ultrafine powders include silica dust and siliceous dust produced as by-products during the production of silicon, silicon-containing alloys, and zirconia, such as calcium carbonate, silica gel, opal silica, fly ash, blast furnace slag, titanium oxide,
Aluminum oxide can also be used.

The amount of ultrafine powder to be used is preferably 5 to 40 parts by weight per 60 to 95 parts by weight of the cementitious material, and more preferably 10 to 35 parts by weight per 65 to 90 parts by weight of the cementitious material. If it is less than 5 parts by weight, it is impossible to obtain high strength, and if it exceeds 40 parts by weight, fluidity decreases. - The water reducing agent used in the present invention is used to improve the wettability and fluidity of the above-mentioned various ingredients and water system, and even if added in large quantities to cement, it will not cause excessive delay in setting or excessive air entrainment. It means a surfactant with a large dispersing power. For example, salts of alkylnaphthalene sulfonic acid formaldehyde condensates, salts of naphthalene sulfonic acid formaldehyde condensates, salts of melamine sulfonic acid formaldehyde condensates, high molecular weight trigenine sulfonates, polycarboxylate salts, etc. as main components. can be given.

The use of these water reducing agents is usually 0.
Although 3 to 1 parts by weight are used, in the present invention it is preferable to add more than that, preferably 1 to 5 parts by weight based on the total weight of cementitious material and ultrafine powder, and 1.5 parts by weight.
-3 parts by weight is more preferred. Water reducers are necessary to reduce contaminants to low (water/cement) ratios, but 10
Exceeding parts by weight will adversely affect the curing reaction.

In the present invention, by combining the water reducing agent and the ultrafine powder, it is possible to obtain fluidity that allows molding by a conventional method even when water/(cementitious material + ultrafine powder) is 25% or less.

The water used in the present invention is necessary for molding, but in order to obtain a high-strength hardened product, it is best to use a fresh matrix as much as possible, and 10 parts by weight of water is
-30 parts by weight is preferred, and 12-25 parts by weight is still more preferred. When the amount of water is more than 30 parts by weight, it is difficult to obtain a high-strength cured product, and when it is less than 10 parts by weight, ordinary molding such as pouring becomes difficult. In addition, in compression molding etc., it is not limited to this, and 10
Molding is possible even when the amount is less than parts by weight.

In addition to the above ingredients, various fibers and nets can also be used as reinforcing materials in the present invention. Examples of fibers include steel fibers, stainless steel fibers, various natural and synthetic mineral fibers such as asbestos and alumina fibers, and natural or synthetic organic fibers such as carbon fibers, glass fibers, polypropylene, vinylon, acrylonitrile, and cellulose.

In addition, steel rods and FR, which have traditionally been used as reinforcing materials,
It is also possible to use a P-rod rod.

In addition, it is also possible to incorporate functional materials such as so-called solid lubricants such as molybdenum disulfide and hexagonal boron nitride to impart sliding properties. It is also possible to use It is also possible to incorporate aggregates, fibers, fine powder, etc. that impart special properties such as thermal conductivity and electrical conductivity.

The mixing and kneading method of each of the ingredients may be any method as long as it can be mixed uniformly, and the order of addition of the ingredients is not particularly limited.

The molded product obtained by molding the kneaded material is cured, and various curing methods can be applied to curing, including room temperature curing, normal pressure steam curing, high temperature and high pressure curing, and high temperature curing. If necessary, a combination of these can be used to obtain a high-strength cured product.

〔Example〕

Hereinafter, the present invention will be explained in more detail with reference to Examples, but the present invention is not limited to these Examples unless it deviates from the technical idea of the present invention.

Example-1 Commercially available white Portland cement (particle size 10.5 μm)
81.7 parts by weight, silica hume (Japan Heavy Chemical Industry
Co., Ltd., particle size 0.1μ? ? iL> 16.3 parts by weight, a salt of a naphthalene sulfonic acid formaldehyde condensate, [Cellflow 110PJ (manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.)] A binder part consisting of 2 vertical sides, and heavy calcined earth shale (particle size 0 .3
~1.0 #1ffl, + National Great Wall) and grid on N (
100 parts by weight of aggregate made by mixing iron balls with a grain size of 0.3 to 1.2s (manufactured by Nippon Kokan Co., Ltd.) at a vertical side ratio of 1:1;
And for the mixture of these binder part and aggregate part, 10
．． 5 and 9.5 parts by weight of water were added and kneaded using a 21 mortar mixer, and the table flow was measured according to JIS-R-5201. Also, using these samples, 4X4X
A 16 cm specimen was prepared, cured at 20° C. for 1 day, cured at 50° C. for 6 days, and then measured for compressive strength.

Note that the specific gravity of the NK grid and the heavy burnt shale in the aggregate is approximately equal, and parts by weight are considered to be parts by volume.

The results are shown in Table 1.

As shown in Table 1, it can be seen that by combining spherical aggregate and high-strength aggregate, fluidity can be significantly improved without sacrificing strength.

The following is the first table in the margins.
Shale To-(am)2 90 10
9.5 220 17503 60 40
9.5 240 1700* /l 100 0 10.5 240 15
705 50 5010.5 2γO1595
6307010, 52751560 7*0 100 10.5 275 1000 Example-2 Bone (as A) irregularly shaped stainless steel and stainless steel balls (particle size 0.3-1°Dam) were used for experiments.

The blending ratio is as follows: the binder part is white Portland cement (Chichibu cement>80 heavy part, 1 part silica hume 2G heavy part, [self 0-110PJ 2 vertical part), and the aggregate part is the total amount of stainless steel balls and irregular stainless steel. The amount was adjusted to 100 parts by weight.The rest was carried out in the same manner as in Example-1.

The results are shown in Table 2. (Experiments Nα1 and Nα5 are comparative examples.) As can be seen from Table 2, it is clear that by incorporating spherical stainless steel, the fluidity is significantly improved without impairing the strength.

1 100 0. 225 166
0 (Results of the Invention) The present invention provides a high-strength mortar concrete with excellent fluidity and excellent strength characteristics of a hardened product. The high-strength mortar concrete according to the present invention can be used as a substitute for metals and ceramics, for example, in molds.

Claims (2)

[Claims] (1) High-strength mortar, characterized in that the aggregate is a combination of high-strength aggregate and spherical aggregate in a system consisting of cementitious material, ultrafine powder, water reducing agent, water, and aggregate. concrete. (2) The mixing ratio of high-strength aggregate and spherical aggregate is 0.0 for spherical aggregate.
5 to 0.7 (capacity ratio), the high-strength mortar concrete according to claim (1).