JPS6265962A - High strength cement composition - 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 [Field of Industrial Application] The present invention relates to high strength cement ffl paraboloids. More specifically, in systems containing cementitious materials, ultrafine powders, superplasticizers, and water, a portion of the cementitious material is replaced with a cementitious material with less aluminate phase to reduce the overall amount of aluminate phase. By doing this, a high strength cement with excellent fluidity at a low water-cement ratio 5! material composition.

[Prior art]

High-strength cement consisting of cementitious material, ultrafine powder, high performance water reducer and water 5! It is a material composition (% published in 1982-
500863]. In this case, it is necessary to have a low water-cement ratio, but the fluidity of the kneaded product at a low water-cement ratio is significantly affected by the type of cement. There is a strong need for the development of a ment composition.

[Problem to be Solved by the Invention 3 Based on the above, the inventors of the present invention have made extensive studies to solve the above problems, and have found that In a system consisting of more, cement 5! The inventors have now completed the present invention by discovering that a high-strength cement composition with improved fluidity can be obtained at a low water-to-cement ratio by using a cementitious material with a small amount of dialuminate phase.

[Means for solving problems]

The present invention is characterized in that a cementitious material, an ultrafine powder, a high-performance water reducing agent, and a water-based system are used in combination with a substance that has less aluminate phase than the cementitious material. be.

The present invention will be explained in detail below.

The cementitious materials referred to in the present invention include ordinary cement, early strength cement, ultra early strength cement, white cement, sulfate-resistant cement, oil well cement, and the like. It is important to replace a portion of the cementitious material with a cementitious material that has less dialuminate phase. The aluminate phase referred to here is calculated based on the Borg formula based on the chemical composition obtained by chemical analysis in accordance with J.Eng.5R5202. Say k.

In general, white cement, sulfate-resistant cement, and oil well cement have less alumina)-1 than normal cement, early-strength cement, and ultra-early-strength cement, and kneelite has even less total cap of C3A, C, and AP. . By using such materials with less aluminate phase in combination with materials with more aluminate phase, fluidity at low water cement ratios is significantly improved. Generally, it is more preferable that the total amount of the aluminate phase is 16.5 inches or less.

Although there is no particular restriction on the amount used in combination, the fluidity improves as the amount used in combination increases. When used together in an amount of 25 parts by weight or more based on 100 parts by weight of the mentogenic substance used, the effects will be more pronounced. Ordinary cement, 1!
Of course, by completely mixing cement and ultra-early strength cement, fluidity can be improved by reducing dialuminate tt as a whole.

It is also possible to use admixtures such as fly ash, pulverized blast furnace slag, expanding materials, rapid hardening materials, high-strength admixtures, etc., and chemical admixtures such as hardening accelerators and hardening retarders in addition to such cementitious materials. .

The expanding material is preferably an ettringite-based material, such as Denki Kagaku Kogyo Co., Ltd.'s cleavage product name [csA+, zo4, or calcined CaO;
It is preferable that the crystal be fired at 0° C. and have an average crystal diameter of 10 μm or less.

Calcium aluminate-based materials are best as rapid hardening materials, such as alumina cement or alumina cement and stone11.
@) Combinations and product names manufactured by Denki Kagaku Kogyo Co., Ltd. [Denka KSJ and Onoda Cement Co., Ltd. product names ``Jet Cement'' are used.

'Also, the high-strength admixture is a gypsum-based filter, such as Denki Kagaku Kogyo Co., Ltd. M product name [Denka E-1000J], Nippon Cement Co., Ltd. product name "Asano Super Mix"
etc. are valid.

The ultrafine powder used in the present invention is at least 1-j--, F
- Glaze moe, l, flat, false short, right - eggplant, θ) and the average grain size is two orders of magnitude lower, which is preferable from the viewpoint of flow characteristics of the mixed material. Specifically, silica dust (silica fume) and siliceous dust, which are by-produced when silicon, silicon-containing alloys, and zirconia are processed, are particularly suitable, and calcium carbonate, silica gel, opalescent silica, fly ash, slag, and oxidized Titanium, aluminum oxide, etc. can also be used. Further, a cementitious material made of ultrafine gold powder can also be used. In particular, it is effective to use ultrafine powder obtained by pulverizing silica, fly ash, and slag using a classifier and a pulverizer in combination to improve curing shrinkage.

The amount of ultrafine powder used is preferably 40 to 5 parts by weight per 60 to 95 parts by weight of the cementitious material, more preferably 55 to 10 parts by weight per 65 to 90 parts by weight. 5
If the amount is less than 40 parts by weight, the effect of developing high strength is small;
If the amount exceeds 1 part by weight, the fluidity of the mixed wire material will be significantly reduced, making it difficult to mold the material, and developing insufficient strength.

The high-performance water reducing agent in the present invention is a surfactant with a large dispersion ability that does not cause too much delay in setting or excessive air entrainment even when added to cement in large quantities, such as a salt of naphthalene sulfonic acid formaldehyde condensate, Salt of melamine sulfonic acid formaldehyde condensate, between molecules! Products whose main ingredients are lignin sulfone powder, polycarboxylate, etc. are available. Conventionally, the amount of high-performance water reducer used is [13~IN! %, but in the present invention, it is preferable to add a larger amount. However, a high-performance water reducing agent is necessary to obtain a mixed material with a low water/(cement + ultrafine powder) ratio, and if it exceeds 1011 parts, it will adversely affect the curing reaction. Preferably, 1 to 5 portions are added to the substance. With the amount of high-performance water reducer used, even if the ratio of water/(cement + ultrafine powder) is less than 25%, the conventional method would be better than the trap of combining all ultrafine powders.
A moldable, fluid mixture can be obtained.

The water used in the present invention is necessary due to the bottom shape, and in order to obtain a high-strength cured product, it is best to use as little as possible.
Preferably, 10-50 parts by weight of water per 100 parts by weight of the mixture of cementitious material and ultrafine powder, more preferably 15-25 parts by weight. If the amount of water is more than 50 parts by weight, it will be difficult to obtain a high-strength cured product, and if it is less than 10 parts by weight, it will be difficult to make irregular shapes such as ordinary pouring. In addition, in the case of a consolidated bottom type, etc., it is not limited to this, but 10
Molding is possible even when the amount is less than parts by weight. Furthermore, it is also possible to use a molding method normally used for cement concrete, such as extrusion molding.

In addition to the above formulations, it is common to use aggregate in combination.

Aggregates used in concrete used in the field of civil engineering and construction may be used, but harder
Specifically, those selected based on the following criteria: Mohs hardness of 6 or more, preferably 7 or more, or Noog indenter hardness of 700 U/■3 or more, more preferably 800 kg/m or more. This is preferable because it can significantly improve the strength. Examples of materials that meet this criterion include silica, emery, pyrite, magnetite, yellow jade, lawsonite, corundum, zenasite, spinel, beryl, and gold. Curb stone, tourmaline, granite, andalusite, cross stone, zircon, calcined bauxite, carbide (I1111 cord, tungsten carbide, 7-erosilicon nitride, silicon nitride, fused silica, fused magnesia, silicon carbide, cubic boron nitride, etc.) There are metals such as iron balls and iron powder.The amount of aggregate used is usually selected within 5 times the weight of the total of cementitious material and ultrafine powder.

However, this is not the case with pre-packed concrete, where aggregate is placed in advance and then poured or poured with paste or mortar, or with post-packed concrete, which is the opposite.

Furthermore, it is also possible to mix fibers and nets for each ridge.

The 7" steel pot is made of various mineral fibers such as asbestos and alumina fibers, as well as synthetic mineral fibers, carbon fibers, glass fibers, and polypropylene,
Examples include natural or synthetic organic fibers such as vinylon, acrylonitrile, and cellulose. - It is also possible to use conventionally used steel rods and FRP rods as reinforcing materials.
is necessary.

In addition, it is also possible to add so-called solid lubricants such as binary molybdenum and 60,000-crystalline boron to provide other functions, such as sliding properties. It is also possible to use carbon, etc., which has a certain property.

In addition, it is also possible to incorporate substances that impart special properties such as thermal conductivity and electrical conductivity. Any method for mixing and kneading the above-mentioned materials may be used as long as they can be mixed and kneaded uniformly, and there are no particular restrictions on the order of addition.

Curing of molded products can be done using different curing methods for each building.
Hi Funa Day: TokiζAshi Zenthi χK Shin
11 "[擺Chhiχf However, any of the curing methods can be employed, and if necessary, these can be combined to obtain a high-strength cured product.

The method described above makes it possible to provide a high-strength cement composition with excellent fluidity.

[Example 1] Normal cement (aluminate phase 1117.8%) was partially replaced with white cement (aluminae phase 1i 12.5%), and the fluidity was completely investigated using the following formulation. After kneading each mixture with a mortar mixer, fluidity was measured using a table 70- (J-K5R5201). However, the crosstalk time was 1 minute at low speed, 2 minutes at high speed, and 1 minute at low speed.

Furthermore, a 4X4X16cW1 specimen was prepared and its compressive strength was measured. In addition, curing is at 20℃, 80% RHj, 50%
C Humid air for 3 days.

Materials used> Cement: Ordinary Portland cement (manufactured by Sumitomo Cement Co., Ltd.) (C, A+04AP 17.8% white Portland cement (manufactured by Chichibu Cement Co., Ltd.) (c3A+c4AF 12.5% λ ultrafine powder Nijirikahium (Il: 1 piece) ff) High-performance water reducing agent: β-naphthalene sulfonate forma IJ condensate system [Cellflow 110 PJ (Daiichi Kogyo Pharmaceutical aggregate): (Sumitomo Metal Mining Co., Ltd.)
2 w or less [Example 2] Neelai synthesized with the cement of Example 1 using KLD slag as a raw material) (c3A+04AP amount a.

%) was used to conduct a similar study.

(Materials used)

Claims (1)

[Claims] 1. In a system consisting of a cementitious material, an ultrafine powder, a high-performance water reducing agent, and water, a high-quality cementitious material characterized in that it is used in combination with a cementitious material having less aluminate phase than the cementitious material used. Strength cement composition. 2. A cementitious material with an aluminate phase of 16.5% or more and a cementitious material with an aluminate phase of 16.5% or less are used together, and the aluminate phase in the cementitious material is 16.5%.
A high-strength cement composition according to claim 1, which has the following properties.