JPH0553739B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to an underwater construction method for a cementitious mixture, which allows a good hardened product to be obtained without separation of materials in water. More specifically, by further blending a water-dispersible epoxy resin and its curing agent into a cement-based mixture containing one or more selected from bituminous emulsion, rubber latex, and polymer latex,
The present invention relates to a method for underwater construction of a cementitious mixture that improves the underwater workability of the cementitious mixture and the physical properties of the hardened product. Conventionally, a water-soluble polymer admixture was added when mixing cement concrete, cement mortar, etc. as a method to prevent material separation when pouring cement concrete, cement mortar, etc. into water. A construction method is known in which cement concrete or cement mortar with a thickened water phase is made and then poured into water. However, this method is not suitable for pouring underwater cement mixtures that have flexibility, appropriate strength, and elastic modulus, such as cement mortar containing a relatively large amount of bituminous emulsion or polymer latex. , by adding a water-soluble polymer admixture,
It has the disadvantage that it has a particularly large effect of reducing strength and durability. The present inventor has discovered that when pouring cement, bituminous emulsion and/or polymeric latex, fine aggregate and other cementitious mixtures in water, especially in seawater,
As a result of continuing research on prevention of strength loss of hardened products and improvement of seawater resistance, we found that by adding a water-dispersible epoxy resin and its curing agent to a cementitious mixture and leaving it for an appropriate period of time, the cementitious mixture was thickened. When poured into water after pouring, there is no separation and dispersion of the material.
It has been found that the construction condition is good, that it cures well in water, that the properties of the cured product are similar to those of ordinary casting on the ground, and that physical properties such as salt water resistance are also improved. Based on these findings, the present invention was completed through repeated experiments. The object of the present invention is to produce bituminous emulsion, rubber latex,
The present invention provides a new construction method suitable for underwater construction of a cement-based mixture containing one or more selected polymer latexes. The present invention also provides bituminous emulsion, rubber latex,
Epoxy resin and its curing agent are added to a cementitious mixture of one or more selected polymer latexes, cement, and, if necessary, aggregate, filler, water, etc. This relates to an underwater construction method for a cementitious mixture, which is characterized in that the cementitious mixture is added and mixed, the cementitious mixture is thickened by an initial reaction between the epoxy resin and its curing agent, and then cast in water and cured. The main materials used in the present invention are explained below. Bituminous emulsions are made of petroleum asphalts such as straight asphalt, blown asphalt, semi-blown asphalt, and proban deasphalt, natural asphalts, heavy mineral oils, tars,
Bituminous materials such as pithus, etc., or bituminous materials mixed with rubber, polymers, resins, naphthenic acids, fatty acids, resin acids, amines, mineral oils, heavy oils, process oils, and plasticizers. , oils, anthracene oil, creosote oil, etc. are added and mixed as appropriate and modified and the bituminous material is emulsified in water using emulsifiers, emulsifiers, dispersants, stabilizers, protective colloids, etc. as appropriate. It is. Also used are bituminous emulsions to which rubber latex, polymer latex, etc. are added. Bituminous emulsion is
Depending on the type of main emulsifier, anionic, cationic,
There are different types, such as nonionic and clay types, and any of them can be used. The most typical bituminous emulsions are asphalt emulsions and tar emulsions. In asphalt emulsions, the evaporation residue is 50-75% by weight, usually 55-70
% by weight, and the penetration of the evaporation residue (at 25°C) is
Approximately 30 to 400 are used. As a bituminous emulsion, a bituminous substance emulsified in the aqueous phase of rubber latex or polymer latex can also be used. Rubber latex and polymer latex include natural rubber latex, synthetic rubber latex, and synthetic polymer latex. With the exception of natural rubber latex, these latexes are obtained by emulsion polymerization. Many synthetic polymer latexes are also called emulsions. For example, latexes such as polyacrylates and acrylate copolymers (e.g., styrene, vinyl acetate, etc.)
It is usually called emulsion. These include: These latexes are those that have good miscibility with cement. Similar to bituminous emulsions, there are nonionic, anionic, and cationic emulsifiers, and any of these can be used. used. Hereinafter, these will be abbreviated as bituminous emulsion, latex, etc. Examples of cements include Portland cement, ultra-fast hardening Portland cement, fly ash cement, blast furnace cement, silica cement, blast furnace colloidal cement, colloidal cement, jet cement, alumina cement, and sulfate-resistant cement. Further, admixtures such as cement shrinkage compensators, hardening accelerators, hardening retarders, AE agents, dispersants, thickeners, foaming agents, antifoaming agents, etc. can be used together with these cements. The epoxy resin used in the present invention is a liquid or solid resin whose main component is a compound having one or more epoxy groups in one molecule. The most common epoxy resin is a condensate of bisphenol and epichlorohydrin (mainly consisting of glycidyl ether of bisphenol).
In addition, condensates of bisphenol and methylepichlorohydrin or ethylepichlorohydrin, condensates of bisphenol and methylepichlorohydrin dimer acid, dimer acid glycidyl ether, polyalkylene glycol glycidyl ether, glycidyl ether of bisphenol alkylene oxide adducts, and fats. Examples include glycidyl ethers such as group glycidyl ether, urethane-modified bisphenol glycidyl ether, aliphatic aromatic co-condensed glycidyl ether, vinyl cyclohexane dioxide, cidiclopentadiene oxide, and hydrogenated bisphenol. These epoxy resins may be used alone or in combination of two or more. In addition, substances that promote the curing reaction between the epoxy resin and the curing agent, such as phenol, cresol,
Alkylphenols, salicylic acid, triphenyl phosphate, furfuryl alcohol, etc. can also be added and used. Furthermore, for the purpose of improving compatibility with elastomers, adhesion, dispersibility in water, etc., these epoxy resins may be added with rodin or hydrogenated rodin and their derivatives, petroleum resins or hydrogenated petroleum resins and their derivatives. , xylene resin,
Alkylphenol resin, terbene resin, coumaron resin, pine oil, plasticizer, mineral oil, fat, solvent,
Nonionic surfactants, fatty acids, resin acids, tall oil, bituminous substances, reactive diluents having epoxy groups, and the like can also be added. In addition, the above-mentioned epoxy resin is reacted with a polybasic acid or its anhydride and neutralized with ammonia water, amines, etc., or a surfactant is added to give water-soluble or water-dispersible properties, or There are resins modified by adding emulsifiers and other additives to epoxy resins so that they can be dispersed in water. These can also be used. The above-mentioned epoxy resins or modified epoxy resins are used after being dispersed in water, or in an aqueous phase such as a bituminous emulsion or latex. Water-soluble, water-dispersible epoxy resins can also be added directly to the cementitious mixture of cement, bituminous emulsion and aggregate.
For epoxy resins that do not have properties such as water solubility or water dispersibility, to disperse them in water, add an emulsifier, emulsification aid, stabilizer, etc. to the water, then add the epoxy resin and mix thoroughly with stirring. can be dispersed. For bituminous emulsions, latex, etc.
Dispersion can be achieved by adding the epoxy resin directly or after adding a small amount of an emulsifier, and stirring and mixing thoroughly. The curing agent used in the present invention is mainly composed of a compound having a functional group that reacts with an epoxy group in one molecule. Specifically, a commonly known one is used. Examples include aliphatic polyamines, aromatic polyamines, cycloaliphatic polyamines, aliphatic hydroxy polyamines, modified polyamines thereof, adducts of these amines, polyamides, keteimines, tertiary amine imidazoles, _BF3 amine complexes, acid anhydrides, Examples include dimer acid, trimer acid, and liquid polysulfide rubber. Among these, some preferred examples include aliphatic polyamines such as diethylenetriamine, triethylenetetramine, tetraethylenepentamine, diethylaminopropylamine, and hexamethylenediamine, piperazine, N-aminoethylpiperazine, and N-aminoethyl imidazoline. Cycloaliphatic polyamines such as aminoethylethanolamine, aliphatic hydroxyamines such as monohydroxyethyldiethylenetriamine, aromatic polyamines such as phenylenediamine, xylenediamine, dimethyldiphenylmethane, tridimethylaminoethylphenol, diaminodiphenylsulfone , dimer acids, trimer acids, or polyamides obtained by condensing these acids with diamines or polyamines, modified amines thereof, amine adducts, water-dispersible imidazoline ring-containing amide compounds as described in Japanese Patent Publication No. 59-49247, and other higher fats. Examples include polyamide compounds such as group diamines, triamines, and polyamines. These curing agents mentioned above are used alone or in combination of two or more. Among the curing agents, those that are water-soluble or water-dispersible are used as they are or in a water-soluble or water-dispersed state. A curing agent that is insoluble or non-dispersible in water is used after being dispersed in water using an appropriate surfactant, dispersant, acid, or the like. Aggregates, fillers, etc. that can be used in the present invention include commonly used natural and artificial aggregates, fillers, etc. Aggregates include gravel as coarse aggregate;
Crushed stone, slag, etc. are used. Fine aggregates include river sand, sea sand, mountain sand, silica sand, foundry sand, crushed glass sand,
These include crushed ceramic sand, crushed granulated sand, magnetic steel sand, crushed iron ore sand, iron sand, whitebait, whitebait balloon, masa soil, and sand made by sintering ash. Special materials include plastic particles, foamed plastic particles, hollow particles whose surfaces are coated with cement, and glass beads, which can also be used. In addition to the commonly used stone powder, fillers can also be made of special materials such as cork powder, powdered rubber, wood powder, sawdust, inorganic fibers, natural organic fibers, etc.
Synthetic fibers, carbon fibers, metal fibers, pigments, mica,
There are ultrafine particles of silicic anhydride powder, metal powder, metal oxide powder, etc., and these can also be used. Furthermore, water includes tap water, industrial water, groundwater,
Rivers, lakes, marshes, seawater, etc. are used. Generally fresh water is used. Water is often used to adjust mixability and workability. Although the cementitious mixtures of the present invention can be used in proportions of each component within a fairly wide range, the following ranges are generally used: For example, in a formulation that does not contain coarse aggregate, 100 to 500 parts by weight of bituminous emulsion, latex, etc. (assuming 60% by weight of non-volatile content), aggregate, filler, etc. (as sand) to 100 parts by weight of cement. 0 to 600 parts by weight, and 5 to 100 parts by weight of the sum of the epoxy resin and its curing agent (as anhydrous). The ratio of the epoxy resin and its curing agent is such that the functional groups involved in the reaction are equivalent or close to equivalent. In formulations containing coarse aggregate, cement
The amount of aggregate (coarse aggregate, fine aggregate,
(fillers, etc.) can be used up to a maximum of about 1900 parts by weight. Mixing of hardenable mixtures can be done using concrete mixers, cement mortar mixers, grout mixers,
Mixing may be carried out using a soil mixer, Pakumil mixer, CA mortar mixer, or other suitable mixer. The order in which the materials are mixed does not matter, but generally the mixer contains aggregate (e.g. sand), cement, bituminous emulsion,
Latex, water, etc. are added and mixed, and then the epoxy resin and its curing agent are added and mixed in order. After adding the epoxy resin and hardening agent, while continuing to mix and stir, the initial reaction between the epoxy resin and its hardening agent usually takes 10 minutes to 2 hours, depending on the type of materials, composition, temperature, etc., to form a cement-based mixture. The aqueous phase becomes thicker. For example, when using a J-funnel with a flow time of about 15 to 30 seconds according to the draft guidelines for prepact concrete stipulated by the Japan Society of Civil Engineers, it gradually thickens and becomes viscous. However, there is still liquidity. In this manner, the cementitious mixture is poured into water after a period of time has elapsed after the materials have been blended, allowing the aqueous phase of the cementitious mixture to thicken. At this point, along with the initial reaction between the epoxy resin and the curing agent, the dispersed particles of the latex and the like begin to gradually aggregate. With this step, even if a cementitious mixture is poured into water, separation of materials such as easily dispersed bituminous emulsion, latex, etc. and cement will not occur. In this way, if the cementitious mixture is cast in water at this stage, there will be no separation of the materials, and the cementitious mixture can be poured, and the cementitious mixture can be cast well and densely, and the cementitious mixture can harden smoothly. The process progresses and a good cured product can be obtained. The materials are generally mixed at room temperature, but when the temperature is low, it is better to heat the bituminous emulsion, latex, water, etc. to prepare a cement mixture. The time required for thickening the cementitious mixture after blending and before casting tends to increase as the amount of bituminous emulsion, latex, etc. added increases. As mentioned above, the construction method of the present invention uses bituminous emulsion,
When pouring a cement-based mixture containing latex into water, epoxy resin and its curing agent are added and mixed, and the initial reaction thickens the aqueous phase to prevent material separation before pouring into water. It has the following excellent effects: (1) When pouring a cementitious mixture into water, there is no separation of the materials, and there is no dispersion of the materials into the water, so a uniform cementitious mixture can be poured into the water. The construction is in good condition and can be done densely, and it does not pollute the water. (2) Without relying on water-soluble polymer admixtures as in the past,
Since the epoxy resin and its effect agent are added and mixed and the initial reaction increases the viscosity before casting, curing progresses smoothly with less influence from surrounding water. Moreover, there is no deterioration in the physical properties of the cured product. Rather, for cementitious mixtures containing bituminous emulsion, latex, etc., the physical properties of the cured product are improved due to the epoxy resin and its curing agent. Furthermore, when considering underwater casting of cementitious mixtures containing bituminous emulsion, latex, etc. mixed with epoxy resin and its curing agent, physical properties of the hardened product deteriorate compared to casting in air. It has an excellent effect of being small. (3) Cement-based mixtures containing bituminous emulsion, latex, etc. are less strong and less rigid than cement mortar, cement concrete, etc., as emphasis is placed on the balance between flexibility and strength of the hardened product. be. Therefore, conventionally, when pouring in water, it was difficult to obtain a good hardened product because it was easily affected by water, but with the construction method of the present invention, it is possible to cast a good hardened product in water. It became possible. (4) Since the epoxy resin and its curing agent are mixed to cause an initial reaction during pouring, the wettability and bonding properties of the cementitious mixture to other objects in water are improved. etc. Next, examples will be described. Example 1 Asphalt emulsion for nonionic cement mixing (60% by weight of evaporation residue, penetration of evaporation residue (25°C) 118), water, early strength Bortland cement, and hardening accelerator were added as shown in Table 1. Mix Denka AM (electrochemical product, trade name, calcium sulfoaluminate type) in this order, and add water-dispersed epoxy resin to this.
DX255 (Ciel Chemicals, product name, liquid anhydride,
Bisphenol glycidyl ether type) and a water-dispersible polyamide curing agent Ebikiure 3255 (Ciel Chemical Products, trade name, liquid water-free) are added and mixed. A mortar mixer was used as the mixer. Mixing was carried out at room temperature of about 20°C. After blending the mixture,
After stirring for about 30 minutes to thicken the cement mixture, determine the flow table value by a flow test based on JIS R 5201 cement physical test, and fill the water tank with water to a depth of 30 cm and line it up in the tank. The cement-based mixture was dropped from a height of 1 m from the water bottom into 6 molds (cylindrical molds with an open top of 5 cm in diameter and 5 cm in depth) to fill them, and then the mixture was placed underwater (20 cm). Cure at ℃). material order 1
The formwork was removed after 1 day, and the compressive strength of the 1-day-old and 7-day-old pieces was measured. No material separation was observed during pouring and curing of the cementitious mixture in water, and the water in the aquarium remained clear without becoming cloudy. Strength is table-
Shown in 1. For comparison, a cement-based mixture was filled into a formwork placed in the air and allowed to harden.
Table 1 shows the results of measuring the compressive strength of wood aged 7 days.
Also listed. For comparison, as shown in Table 1, 30
After stirring for a minute, the cement-based mixture was dropped from a height of 1 m from the water bottom into a formwork lined up on the bottom of water at a depth of 30 cm to fill it, as in the example.
Most of the material was dispersed and no specimen could be taken.

[Table] Example 2 In a cement mortar mixer, 100 parts by weight of early strength Portland cement, 200 parts by weight of river sand, 50 parts by weight of cationic chloroprene rubber latex for mixing with cement, and cationic asphalt emulsion for mixing with cement.
MK-3 (evaporation residue 60% by weight) 50 parts by weight, water 35
Add parts by weight, mix and stir, and add Epicoat to this.
25 parts by weight of DX255 and 25 parts by weight of Epicure were added, mixed for about 60 minutes to thicken, and then poured into an underwater formwork at a depth of 30 cm from a height of 1 m to fill it. No separation of the cementitious mixture in water was observed, and the curing was good. Example 3 In a cement mortar mixer, 85 parts by weight of early strength Portland cement, 15 parts by weight of Denka AM, and 200 parts by weight of river sand
Add parts by weight, 50 parts by weight of styrene-butadiene rubber latex for cement mixing, and 40 parts by weight of water and mix. 15 parts by weight of Epicote DX255 and 15 parts by weight of Epicure were added to this, mixed and stirred for about 80 minutes to thicken it, and then poured in water in the same manner as in Example 1.
No separation or dispersion of the cementitious mixture was observed, water was not contaminated, and the cementitious mixture was well cured.

[Claims]

1 One or more cement dispersants (A) selected from the group consisting of lignin sulfonates, oxycarboxylate salts, and polycarboxylate salts and 0.1% of the cement dispersant (A) in a penetration power test using the canvas disc method. Contains one or more nonionic surfactants (B) selected from the group consisting of polyoxyalkylene alkylaryl ether and polyoxyalkylene alkyl ether, which have an aqueous solution penetration power of 60 seconds or less at 25°C. An admixture for cemented carbide concrete.