JPS5932416B2 - Heat-hardening hydraulic bonding material and its molding method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a heating rapid hardening hydraulic bonding material (hereinafter referred to as thermoset cement).

A molding method that uses a hydraulic bonding material to obtain a stable pot life (or setting start time), hardens rapidly when heated, and can be immediately demolded has never been proposed. .

With conventional methods, for example, early-strength cement does not harden rapidly even when heated, but rapid-hardening controlled cement, which hardens rapidly in a short period of time (within 1 hour), hardens quickly and has strength if heated without adjustment. However, the pot life was short, and if the pot life was adjusted to 2.5 hours, which is the same as that of ordinary cement, it did not harden rapidly even when heated.

In addition, even if it is heated and rapidly hardened by any heating means such as atmospheric temperature, heat conduction temperature, far infrared rays, and ultrasonic vibration at normal pressure, it will be hardened from 1001<g/ci to 350kg/ci within about 30 minutes.
No demolding strength of cyyt was generated.

Furthermore, there has been no method of laminating thermocera cement hydrates of the same or different types with different types of hydrates or molded building materials, etc., and rapidly hardening and molding them by heating.

However, the method of the present invention has made it possible for the first time to heat a single-layer or multi-layer structure to rapidly harden it, quickly remove it from the mold, and mass-produce it.

In terms of time, since it is possible to demold the mold after 10 to 30 minutes of heating, a continuous production line can be used.

Furthermore, when performing factory production, unless the time for each process is constant, it is not possible to set up a continuous or semi-continuous mass production line.

There is a rapid-hardening cement that hardens rapidly at room temperature at any time.

This has the advantage that the pot life can be adjusted according to the temperature, but has the disadvantage that the rapid hardening conditions set as specific conditions change according to changes in the temperature from morning to afternoon.

Therefore, in Japan, where the temperature fluctuates throughout the four seasons, it is difficult to apply a production line that is established in a fixed process time, and it is preferable that the molding process continues for a long time without condensation and hardening even if the temperature changes. There was a desire for thermoset cement, which has properties similar to thermosetting synthetic resins, but when heated and the hydrate reaches a certain temperature, it rapidly hardens and develops demolding strength. .

The rapid hardening controlled cement, which can be rapidly set at room temperature at any time, proposed by the present inventor in Japanese Patent Publication No. 48-40444, and the jet cement by Onodesha, have a regulating effect mainly using a setting regulator (called a chelating agent) consisting of an organic compound. However, in the absence of a chelating agent, it has a pot life of only around 15 minutes at room temperature, and if the pot life is extended, curing will be slow and it will not harden rapidly, so it cannot be used as a rapid hardening cement.

Also, even if you add a chelating agent to adjust the pot life to 1 hour at room temperature, the pot life will be shortened to around 20 minutes at temperatures above 30 degrees Celsius in the summer, so it will harden naturally after 20 minutes after heating, but in the summer If the pot life is adjusted to 1 hour at 30°C or higher, the hydrate will not harden rapidly even if the temperature reaches 80°C within 20 minutes of heating.

Therefore, Japanese Patent Application No. 47-5561 (Special Publication No. 53-2496)
As proposed in No. 8), it is necessary to extend the pot life by maintaining the hydrated rapidly hardening cement at a temperature of 15° C. or lower to extend the pot life and rapidly harden it by heating.

This is the first proposal in the art for a phasic method in which a rapidly hardening hydraulic bonding material such as that of the present invention is heated and rapidly hardened at any time during its pot life.

The method according to the present invention is to keep a hydrate mainly composed of thermoset cement, which has a pot life sufficient for molding operations, at natural temperature and heat it at any time before it begins to set. The process consists of rapidly hardening this by raising the temperature to 60° C. or higher to develop demolding strength.

Thermoset cement as referred to in the present invention has a pot life sufficient to perform molding operations at ambient temperature, but it can be heated at any time before it starts setting and hardening to form hydrates. A hydraulic bonding material that rapidly hardens and develops demolding strength when heated above a certain temperature.

Such thermoset cement has a long and stable pot life in all seasons including summer.

More specifically, thermoset cement has Ca
O・Al2O3 hydraulic compound alone or together with CaO
・Cement containing either a mixture with a 5102 hydraulic compound and a hydrofluoric acid by-product anhydrite containing hydrofluoric acid or calcium fluoride, or a phosphoric acid by-product anhydrite containing phosphoric acid or calcium phosphate and hydrofluoric acid or calcium fluoride , or a cement in which an organic compound having a setting adjustment effect is further added to such cement, and if heated at any time before the start of setting, it will harden rapidly when the temperature of the formed hydrate reaches 60°C or higher. It is a hydraulic bonding material that hardens rapidly when heated to generate demolding strength.

The above cement may contain gypsum hemihydrate and gypsum trihydrate (regardless of whether it is by-product gypsum), lime (quicklime, slaked lime, dolomite, dolomite plaster, calcined products of these, etc.), and water. Glass or synthetic resin may also be added.

Examples of the setting regulator include citric acid or a compound thereof, ketocarboxylic acid, ascorbic acid, 2-ketogluconic acid, ketogel tar acid, and the like.

The compositions of the hydrofluoric acid by-product gypsum and the phosphoric acid by-product gypsum used in the present invention are as follows.

Composition of hydrofluoric acid by-product gypsum (Nitto Fluorine's hydrofluoric acid by-product gypsum)
Content (wt, %) CaO38.2 80354.6 Sin21.5 Fe2034.2 CaF2 Rice 1.2 99.7 Rice Fluorine exists in the form of HF in gypsum.

Phosphoric acid by-product gypsum (by-product gypsum manufactured by Ueno) Composition Content (wt, %) CaO39,3 SO:356.2 Sin20.7 F e 203 0.5 CaF rice 10.3 P2O2-*-21,4 A.I.

031.299.6 Rice 1 Some fluorine exists in the HFO form in gypsum.

Rice 2 Exists in gypsum in the form of phosphoric acid or calcium phosphate.

Thermoset cement is roughly divided into two types. 3 One type is a mixture of CaO・A1゜03 hydraulic compound (hereinafter referred to as alumina cement) and one or more of the above gypsums in an arbitrary ratio. or an inorganic compound such as CaO.5i02 hydraulic system (hereinafter referred to as Portland cement) or lime which becomes basic when hydrated into a secondary mixture.
It is a hydraulic bonding material that does not contain more than 30% of a basic component containing an organic compound such as an amine compound that becomes strongly alkaline when hydrated.

The other type has Portland cement as its main component, with 10 to 40 parts of alumina cement (practically 15 to 25 parts).
This is a hydraulic bonding material containing 5 to 30 parts of the above-mentioned gypsum and a setting regulator.

However, the pot life was much shorter than when using by-product gypsum.

Further, a hydraulic joint is obtained by optionally adding one or more selected from lime, water glass, an organic compound having a setting control effect, a synthetic resin, etc. to the above two types of joint materials, as necessary. The material also belongs to thermoset cement.

The conditions are satisfied if the material is heated at any time before the start of solidification to rapidly harden it.

Even if it is a rapidly hardening cement whose pot life can be adjusted without heating, it is within the scope of the present invention if it has a sufficient pot life and is rapidly hardened by heating at any time during the pot life. .

However, these so-called room-temperature-curing rapid hardening cements cannot be unconditionally used in the present invention because they harden rapidly by heating only when the pot life is adjusted to within one hour at room temperature.

However, even if the pot life is adjusted to, for example, 2 hours, left to stand for 1.5 hours, and then rapidly hardened by heating, it is within the scope of the present invention to rapidly harden by heating at any time before the start of setting. Changes in temperature will cause variations in curing time.

Even if the amounts of alumina and SO3 components in cement are the same, the properties of the alumina and SO2 components are completely different depending on the type, so the action and effect cannot be limited by the ratio of the components contained.

It is known that the coexistence of small amounts of fluoride and phosphoric acid components in the alumina component and SO3 component prolongs the setting time, but the coexistence of these components does not interfere with thermosetting, so it is not a problem.

Also, depending on the firing temperature and powderiness, it may be unsuitable for room temperature curing but effective for thermosetting.

It is also possible to use the thermoset cement of the present invention as the main material and to improve it by using thermosetting resins, thermoplastic resins, and organic compounds, and it is also within the scope of the present invention to rapidly harden by heating using such materials.

In the method according to the present invention, the thermoset cement as described above is kept at natural temperature for an arbitrary period of time before its scheduled setting start time, and is heated at an arbitrary time to a temperature of 60°C or higher. Let the temperature rise.

If heating is continued for a certain period of time, thermoset cement will rapidly harden and develop high strength, easily achieving demolding strength.

On the other hand, if it is not heated to 60°C, it will coagulate but not harden.

There are no particular limitations on the heating mode, but when thermocement hydrate is cast into a mold and heat-cured, the cast hydrate shrinks or expands when it is heated and cured. Conversely, it is desirable to use a surface forming material in the formwork that does not expand or contract when heated.

If the surface forming material expands due to heating, or if the hydrate cures and contracts due to heating, the surface layer of the hydrate will necessarily be destroyed during curing and will not become dense.

There is a well-known method of molding a luminous surface layer by casting alumina cement hydrate at room temperature using glass or hard or semi-hard synthetic resin as a base plate, but if this is heated and hardened, Since the hard synthetic resin expands and the cured hydrate body contracts, the expansion and contraction of the seki plate and the molded body are reversed, and the surface layer is destroyed, resulting in no gloss.

Normally, hydrates harden and shrink when heated, but in this case, if plastics, stretched films, sheets, etc. mixed with plasticizers, which have the property of shrinking when heated, are used for the support plate,
Even when heated, both the plate and the cured product become shrinkable, resulting in a dense surface layer.

If metal or glass is used as the plate, it expands when heated, so thermoset cement must be used, as it expands when hardened.

By applying strong pressure and tightening to suppress the strain caused by expansion and contraction,
There is also a method of heating and curing molding, but the molding cycle is slow, the defective rate is high, and productivity is low.

The purpose of applying strong pressure is to suppress the expansion and contraction strain caused by heating of the plate and the hardened material, and although it is theoretically possible, it is extremely difficult in practice.

The method of the present invention enables high-cycle mass production with simple equipment without pressing under normal pressure.

It goes without saying that clamping to a low pressure is within the scope of the present invention as long as the principles of the present invention are used.

The present invention can also be used to form thermoset cement moldings with multiple stations.

When the structure according to the present invention as described above is used as a surface layer and a backing layer is further provided to form a plurality of structures, it is necessary to reduce the hydration water in the backing layer until the surface layer is cured by heating. It is desirable that the backing layer be molded in such a way that it retains water and maintains a moist state.

The backing layer can be made of thermoset cement with the same or different composition as the surface layer, a hydrate of a room-temperature curing hydraulic binder, or already molded building materials.

The hydrate of the surface layer treated and shaped according to the present invention is
It absorbs and dehydrates excess water and retains only hydration water close to the theoretical value.

When the backing layer is heated, if the surface layer is also heated and the hydration water retained therein is reduced, curing will be poor and a dense surface layer will not be obtained.

If the front and back layers are made of thermoset cement hydrate with the same compounding material, if the water ratio of the backing layer is high, it will not dry before the surface layer hardens, and for example, the surface layer will be
Even if thermoset cement hydrates with different curing temperatures are used, such as starting hardening at 0°C and thermosetting the backing layer at 80°C, the cement remains moist until the surface layer hardens, making it effective. be.

In addition, even hydrates like calcined gypsum that harden rapidly at room temperature have good water retention properties, so if they contain excess water, they retain water and maintain a moist state even when heated. It can be used as a backing layer.

In addition, molded building materials that contain water and retain moisture, such as gypsum board, silica board, asbestos pulp board, and foamed concrete, can be used by impregnating them with water and keeping them moist until the surface layer hardens. You can also do it.

Although slow-setting cement cannot be removed from the mold early, there is no problem in using it.

However, cement that hardens rapidly in a short period of time is not suitable because it hardens rapidly, generates heat, dries, and dehydrates the surface layer.

Furthermore, when thermoset cement hydrate is heat-cured and molded, especially when molding a multi-layer structure consisting of a surface layer and a backing layer, it is necessary to close it almost completely, but avoid completely sealing it. It is desirable to carry out heat curing.

In order to thermally cure thermoset cement hydrate, it is necessary to raise the temperature of the hydrate uniformly and rapidly so that it begins to harden, and it is also necessary to prevent water shortage, so the hydrate must be closed. However, since air bubbles will diffuse if the container is sealed, it is desirable not to seal the container tightly.

When a thermoset cement hydrate is molded with the required water retention amount as in the present invention and hardens rapidly when heated, lack of water causes poor hardening.

It is known that when cement is heated to accelerate its hardening, it is covered with a sheet to keep it warm, but even if it is not covered, it will not harden and cause poor hardening.

It is sufficient to replenish the water by sprinkling water.

When thermoset cement is heated and hardened rapidly without being closed as in the present invention, firstly, it is exposed to high ambient temperature,
When a cast mold is placed, hardening begins from the surface in contact with the atmosphere, and the surface layer of hydrates is dehydrated, resulting in poor curing.Even if heating is done from the bottom of the mold, heat is generated due to vaporization. As a result of the dissipation, the temperature of the upper layer does not rise rapidly, resulting in water shortage and poor curing.

Unless the temperature of the cast hydrate rises uniformly and rapidly, the object of the present invention cannot be fully achieved.

Secondly, as mentioned above, since the hydrate is maintained at the required amount of water, it is obvious that if it is heated and the water evaporates, there will be a water shortage, resulting in poor curing.

Therefore, in the case of the present invention, it is highly desirable to close the cast hydrate.

However, hermetically sealing them also does not necessarily yield the desired results.

If it is sealed, the backing layer retains excess water, which heats up and forms bubbles, destroying some of them.

This is particularly noticeable in fibers and lightweight aggregates, which contain air bubbles.

When using a hydrate that hardens quickly at room temperature, such as plaster, for the backing layer, it has good water retention even if it is not closed, so hardening does not occur. Therefore, in such cases, heat forming without closure is particularly effective.

Even if a moist, water-containing molded building material is used for the backing layer, heat molding can be similarly performed without closure as long as it retains moisture.

However, it can be said that in these cases the molded building material itself is used to close the thermoset cement surface layer.

The expansion and contraction of the cured molded product that occurs when the hydrate of the surface layer treated and molded as described above and the hydrate or molded product used for the backing layer are simultaneously heated and cured or dried is treated as a molded product. The type of bonding material used for the shape, the water mixing ratio, water content ratio, aggregate ratio to the bonding material, the amount and type of reinforcing material, and the molded product are selected and used to form a hydrate, and heated at the same time. It is desirable to cure, dry and form into a dimensionally stable laminate.

Using thermoset cement, a structure having a beautiful surface layer that is dense, hard, and has little water permeability can also be molded by thermosetting according to the present invention.

In this case, for example, a hydrate is poured into a mold, the mold is pressurized to form floating ice, and the structure is formed by substantially completely removing excess water.

If the water-to-cement ratio of the hydrate constituting the surface layer is high, cracks will occur in the surface layer after heat curing and drying, or a large number of dehydration holes will be formed, and a dense surface layer will not be obtained.

Also, if the water-cement ratio is made small, high strength and hardness can be obtained, but many pores are created in the surface layer, so water permeability cannot be made too low, and the surface cannot be made beautiful.

Even if excess water is simply removed by applying pressure while applying vibration, dehydration holes remain and a dense surface layer cannot be obtained.

Further, even if vacuum dehydration is performed under pressure, the dehydration surface becomes clogged and dehydration cannot be completed almost completely, and if vacuum dehydration is performed sufficiently, dehydration holes remain.

Even when dehydrating in vacuum and then molding under pressure, it is impossible to remove only excess water from the hydrate, and excessive dehydration will result in poor curing due to heat curing.

Furthermore, even if vacuum kneading is carried out using the theoretical amount of water and cast molding is performed, it is not always possible to knead the mixture under conditions where there is no excess water due to differences in particle size, particle surface area, and solubility. It is impossible to prevent it from remaining.

In fact, with known techniques, it is nearly impossible to remove only excess water from a hydrate before hardening the hydrate.

If excessive water is absorbed, curing will be poor, and if excess water remains, pores will remain.

Thus, it has been extremely difficult to reduce the water permeability from the surface without causing poor curing.

A simple way to prove this is to mix pigments and check whether the color develops or maintains its color.
Unless the treatment of the present invention is carried out, color development will be maintained for a long time and bright colors will not develop.

In the present invention, the hydrate cast into a mold is pressurized to extrude excess water to the side to make it float, and by almost completely absorbing and dehydrating this excess water, the surface layer is formed after thermosetting molding. Do not leave any air bubbles or evaporation pores.

In the molding process of the present invention, the thermoset cement is heated to 60° C. or higher to rapidly harden it, so if there is excess water remaining in the cement, it evaporates during heating, and evaporation holes are formed in the cement after the cement hardens.

The method of the present invention allows the above-described molding to be carried out without such consequences.

To pressurize the hydrate and make the excess water float, pressurize with a shaping material so as not to destroy the surface of the hydrate. There are methods such as pressurizing a part of the water to spread it over the entire surface, or applying pressure and absorbing water using a shaping material whose surface material is a spongy body, a foamed product, a fiber material, or the like.

These methods are even more effective if they are carried out while applying vibration.

Although the embodiments of the present invention have been described above, focusing mainly on molding by mold casting, it is clear that the present invention can also be used for molding without using a mold, depending on the circumstances.

Next, an actual case is shown.

Actual case 1 A mixed cement consisting of 64 parts of Portland cement, 20 parts of alumina cement, 10 parts of anhydrite, 5 parts of gypsum hemihydrate, and 1 part of gypsum trihydrate has a pot life of only about 15 minutes at room temperature and requires a chelating agent to adjust. However, 64 parts of Portland cement,
A mixed cement consisting of 18 parts of alumina cement, 15 parts of anhydrite as a by-product of hydrofluoric acid, and 3 parts of gypsum as a by-product of phosphoric acid does not require a chelating agent and has a sufficient pot life. When the temperature reached 80°C, it hardened rapidly.

Actual flame example 2 Denki Kagaku Co., Ltd.'s alumina cement (Denka No. 1) and Nitto Fluoro's hydrofluoric acid byproduct gypsum were fired at 60°C to produce anhydrous gypsum (600°C).
The mixtures with free ratio of calcination) showed a pot life of 200 minutes or more at 20° C. under the condition of W/C=0.35.

The pot life was measured when the Vicat needle sank 2%.

2 (JX 2 Cl11x 8σ metal formwork, S/
After pouring various mixed cements adjusted to C=1, W, /C=0.45, put them in a moist curing box and adjust the thermostat to 80℃, heat for 30 minutes, then take it out and cast it for 15 minutes.
After cooling, the strength was immediately measured.

Typical results are shown in the table below. Actual Case 3 Tests were carried out using the same test method as Actual Case 2, with ordinary cement added and various types of gypsum, and the results are shown in the table below.

Alumina cement electrification No. 1 Ordinary cement indicated by the symbol 1 PC Nitto Fluorine by-product gypsum 600° calcined anhydrite C8 Ueno trihydrate gypsum 2C8 Example 4 Alumina cement in actual case 3 was mixed with ferrous oxide, ferric oxide, Asahi Glass Co., Ltd.'s alumina cement (trade name) Asahi Fuonche) (referred to as H2) contains titanium oxide as a component, and ordinary cement is replaced with Nippon Cement's early-strength Portland cement (product name) containing chromium oxide and manganese oxide.
When the product was replaced with Super Velo (trade name) (referred to as SVC), the pot life was extended and the initial strength was also good.

Actual case 5 In addition, Super Velo used in Actual Example 4 was 64%, Nippon Cement Co., Ltd.'s Alumina Cement No. 1 was 20%, anhydrite calcined at 600°C of the above-mentioned hydrofluoric acid by-product gypsum was 12%, and hemihydrate gypsum 4.
% compounded cement had a pot life of only 25 minutes at 20°C, but when the alumina cement was replaced with Asahi Fuonsh, the pot life was extended to 120 minutes at 35°C, and the 45-minute strength using the above method was 175 kg/ cI? It was L.

In this actual case, if alumina cement is 10% or more, 60
By raising the temperature of the hydrate between 100°C and 100°C, the hydrate could be cured and demolded in a short time.

Actual case 6 Ultra early strength cement manufactured by Nippon Cement 60 parts Alumina cement No. 2 manufactured by Nippon Cement 22 Anhydrous gypsum calcined at 600°C of fluorine by-product gypsum 8 Hemihydrate gypsum manufactured by Ueno gypsum
5 Sodium citrate (reagent)
■Slaked lime (reagent)
The pot life for the formulations of 501 or more was 4 hours or more.

One hour after mixing with standard mortar, it was heated with saturated steam at 70°C.

Immediately removed from the mold, compressive strength 30 minutes after stopping heating is 105
kg/crit and 410 kg/ff after 4 weeks
It became l.

Actual case 7 Electrification No. 1 alumina cement 85%, ordinary cement 5%,
The cement mixed with 10% anhydrite calcined at 600°C of the hydrofluoric acid by-product anhydrite has a pot life of more than 200 minutes at 20°C, but this cement has S/C=1, W/C=
A 0.45 mm mortar was poured into an iron plate form, a thermocouple was inserted into the mortar as well as the form, and the temperature was observed while heating with an infrared lamp.

When the mortar temperature exceeded 60° C., there was a sudden rise in temperature, which is considered to be due to curing heat generation.

When the temperature reached 60° C., the heating was stopped, but after that, it still showed a rapid rise and hardened.

Actual case 8 90 parts of a mixed cement of 85 parts of alumina cement, 10 parts of the hydrofluoric acid vibro-calcined anhydride, 5 parts of Portland cement and 10 parts of green inorganic pigment were mixed at a water-cement ratio (W/c) = 0. 45, sand-cement ratio (S/C) =
Formwork with embossed 0.1% thick soft sheet mixed into the mortar of 1 as a side plate↓This is 1% of the above mortar.
It was cast to be thick.

Excess water was absorbed and dehydrated while applying pressure with a semi-hard sponge having an uneven surface.

After this, glass fibers were placed, and the mortar mixed above with W/C=0.6 was placed on the backing and cast to a thickness of 3%.

Gently shape it with a sponge while absorbing water, and then polish the top.
Cover it with a film made of divinyl vinyl and heat it in a steam curing chamber adjusted to have a thermostat at 70℃.
After 0 minutes, the mold was removed immediately.

There was no efflorescence at all and a beautiful color pattern was exhibited.

In addition, when the length change of 1 m was examined, the warpage was slight.

S/C=1, W/C= of the cement used in this actual case
0.45, the pot life of the mortar at room temperature is over 200 minutes, and the compressive strength after heating at 70℃ for 15 minutes is 3.
40 kg/ffl, 7 days later 560 kg/crj,
It became.

Example 9 The mortar used in Example 8 is embossed with 0.2%! It is poured to a thickness of 0.5% into a formwork made of leather and pounded with an uneven hard rubber to make the excess water float, then it is absorbed and dehydrated with a water absorbing mat, a glass cloak is placed on top of this, and it is further separated. A mixed cement consisting of 64 parts of alumina cement, 8 parts of hydrofluoric acid byproduct anhydrite, 8 parts of calcium sulfite, 2 parts of trihydrate, and 18 parts of Portland cement was prepared with W/C=0.7 and S/C=
The mortar was adjusted to No. 1 and poured into the backing layer.

A film was placed on top of this and heated with a far-infrared lamp.

When the temperature of the molded body reached approximately 70°C, the surface layer was already hardened and the backing layer showed rapid hardening.

When the mold was removed directly, the surface layer showed a beautiful colored uneven pattern.

Also, no warping occurred. The cement used for the backing layer has a pot life of 200 minutes or more at room temperature, and its S/C =
1. When thermally cured at 70°C ambient temperature for 30 minutes at W/C = 0.45, the strength was 180 kg 45 minutes after the start of heating.
/ffl reached 490ky/i after 7 days.

Example 10 After placing a glass mat on the molded surface layer of Example 9, 0.03 citric acid was mixed into the calcined gypsum to extend the pot life, pearlite was used as the aggregate, and W/C= 0.8, S/
The product was adjusted to C=0.5 and cast, and then the molded product was made into 9. Kaibara, and then a mat was added and cast.

Since gypsum has good water retention properties, it was heated at an ambient temperature of 80° C. without being closed.

After 30 minutes, the heating was stopped, taken out, cooled, and demolded.

The surface layer showed a beautiful pattern and was sufficiently hardened, and the plaster of the backing layer was hardened and still moist.

The calcined gypsum used for the backing layer hardens rapidly even at room temperature, but when alumina cement and trihydrate or anhydrite are combined and made into mortar with alkaline water, it does not harden rapidly at room temperature when heated.
Although the temperature varies depending on the formulation, it hardens quickly, so it could be used as a backing layer.

However, the pot life was much shorter than when using by-product gypsum.

Example 11 When molding under 80 actual case conditions, an iron plate was used as a surface plate, a mold was placed on top of it, a thermocouple was attached to the molded hydrate and the iron plate, and the iron plate was heated to adjust the temperature of the molded hydrate. Heating was stopped when the temperature reached 60°C.

After 6 minutes, it was observed that the mold hardened and developed demolding strength, so it was cooled and demolded immediately.

Example 12 62 parts of Portland cement, 20 parts of alumina cement, and 18 parts of the hydrofluoric acid by-product anhydrite were mixed to make cement, which was made into S/C=1, W/C-〇, 450 mortar, and stretched polypropylene. A resin film is poured into a formwork with a side plate to make it 1% thick, and then spread over the whole area while applying pressure with a protruding rod to make the excess water floating, and the second surplus water is poured into silica gel. Then, mortar of the same cement with S/C = 1 and W/C = 0.7 was cast to a thickness of 2%, and chemical fiber cloth was press-fitted on top of it while applying vibration. Then, I used a sponge to reshape it and absorb water.

This is covered with a film and heated with far infrared rays, and the molded product becomes 80%
Heating was continued until the temperature reached .degree. C., and 30 minutes after heating, the heating was stopped, cooled, and demolded.

After one day, the compact was subjected to a water permeability test using a cylinder water column, which is a known test method, but the water permeation amount was so small that it could not be measured.

The surface was smooth and had light heat.

I also tried using brass powder instead of sand for the surface layer, and the surface was made of metal, resulting in a beautiful and highly conductive surface layer.

Reference Example In Case 10, s without using glass fiber
/c=2. It was lined with mortar of W/C=0.45 and thermosetting molded in the same way, but it warped after 3 days.

Example 13 7% of a rust-colored pigment was added to a cement containing 90 parts of alumina cement, 5 parts of hydrofluoric acid by-product anhydrite, and 5 parts of Portland cement to give S/C=1 and W/C=0.45. The mold was poured to a thickness of 1% into a mold made of a sheet of POLJ4 vinyl with an uneven pattern similar to natural stone that had been adjusted to mortar, and the excess water was dehydrated while applying pressure in the same way as described above. Further, a glass mat was placed and lined with 3% thick mortar of S/C = 1.5 and W/C = 0.7 of mixed cement of 60 parts of alumina cement, 18 parts of anhydrite, and 22 parts of Portland cement. After that, water was absorbed and dehydrated, and 0.3 part of citric acid was added to jet cement manufactured by Onoda Cement Co., Ltd. to extend the pot life, and the mixture was made into a mixture of 1 part of cement: 2 parts of sand: 3 parts of gravel with W/C = 0. 6 concrete was mixed and cast to a thickness of 50 parts.

A sheet was placed on top and heated in a steam atmosphere temperature of 80°C.

The formwork was made of iron plates, which had good heat conductivity and hardened in about 30 minutes.

After 30 minutes of cooling, the mold was removed, resulting in a concrete plate with a beautiful surface layer.

Claims (1)

[Scope of Claims] I CaO・Al2O3 hydraulic component alone or a mixture of this and CaO-8IO2 hydraulic component, and hydrofluoric acid or a hydrofluoric acid by-product anhydrite containing calcium fluoride or phosphoric acid or Contains phosphoric acid byproduct anhydrite containing calcium phosphate and hydrofluoric acid or calcium fluoride, and can be rapidly hardened by heating to raise the temperature of the molded hydrate to 60 degrees Celsius or higher at any time before the start of setting. A hydraulic bonding material that hardens rapidly when heated to the point where it develops demolding hardness. 2 Ca0-Al□03 hydraulic component alone or a mixture of this and CaO・S J02 hydraulic component, and hydrofluoric acid by-product anhydrite or phosphoric acid or calcium phosphate containing hydrofluoric acid or calcium fluoride and phosphoric acid by-product anhydrite containing hydrofluoric acid or calcium fluoride, and further contains an organic compound having a setting adjustment effect, and heated to a temperature of 60 degrees Celsius at any time before the start of setting. A rapidly hardening hydraulic bonding material that hardens rapidly when heated to a temperature above 100°C and exhibits demolding hardness.