JPS5845932B2 - Manufacturing method for glass fiber reinforced cement products - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention manufactures glass fiber reinforced cement products in which glass fibers are mixed in cement mortar so that a cement product with superior mechanical strength can be obtained despite its wall thickness. Specifically, after clamping the cement mortar containing glass fibers supplied in a formwork that has a pressure-resistant structure and has a filter for dehydrating excess water on at least one of its inner surfaces, the cement mortar is By applying pressure, the excess water in the cement mortar is passed through the filter and dehydrated until the cement mortar can maintain its predetermined shape. After that, it is demolded and cured to form a glass fiber-reinforced cement product. Relating to a method of manufacturing.

When implementing this type of method, the most important point in terms of product finish, and which has been considered a problem in the past, is the performance of the filter.

In other words, this filter must (a) be superior in its ability to filter and dehydrate excess water, ←) be superior in its ability to efficiently capture fine cement particles, and (iii) be uncured during demolding. Excellent interfacial releasability with existing cement mortar.

is required.

Among these, the one that causes the most problems in terms of product finish is ←
Regarding the interfacial releasability mentioned in →, it would be no exaggeration to say that there are no existing filters that have sufficient performance in (a) and (b) above and also excel in this aspect. Not.

Therefore, when the filter is peeled off from the uncured cement mortar during demolding, a portion of the cement mortar adheres to the contact surface of the filter with the cement mortar and is removed together with the filter, resulting in the cement mortar surface being unduly damaged. It was inevitable that the surface would be roughened and the surface finish would deteriorate.

In view of the above circumstances, it is an object of the present invention to propose a method for manufacturing glass fiber reinforced cement products that can produce products with a very good surface finish, and is an object of the present invention. This method is characterized in that a release agent made of fine particles is sprayed on the filter surface that comes into contact with the poured cement mortar.

In other words, when using the method of the present invention, (A) and (RO) of the above-mentioned (A), (B), (/→) are required for the finished product when implementing this type of manufacturing method. ), the interface can be improved by spraying a release agent consisting of fine particles alone or in the form of a slurry on the surface of the filter that is in contact with the cement and mortar. By improving the releasability, it is possible to prevent deterioration of the surface finish caused by part of the cement mortar remaining attached to the filter surface being peeled off from the cement mortar surface when the filter is removed.

In addition, the manufacturing cost is low because we use a release agent made of fine particles that are easily available, such as sand, plastic particles, and organic particles, and the economic burden is extremely small even if it is consumed once. It has now become possible to suppress the increase in surface finish as much as possible and produce products with a good surface finish at a relatively low cost.

Examples of the method of the present invention will be described in detail below based on the drawings.

As shown in Fig. 1, one bottom formwork has a collective drainage chamber 1a and a drainage hole 1b at the bottom, a side formwork 1B and a drainage hole 1c.
5 to 100Av/cf1 with the upper formwork 1c having
．． Of the formwork 1 configured to withstand a pressure of preferably 10 to 60 kg/crrt, except for the upper formwork 1c (formworks IA and IB are assembled, excess water is dewatered while covering the entire inner surface of the formwork). Filter 2 (this can be made of any material other than the above-mentioned materials, such as paper, felt, canvas, sintered body, etc., as long as it can effectively filter cement particles while only allowing water to pass through). It's okay.

).

The convection pouring cement mortar contact surface of the filter 2 contains fine particles having an average particle size within the range of 44μ to 300μ, such as sand, metal particles, plastic particles, organic particles, etc. For example, JIS G 5901 (mold A release agent made into a slurry by mixing and dispersing silica sand with a particle size of No. 150 as specified in the Japanese silica sand in water to a concentration of 10 to 50 by weight is sprayed and applied at a rate of 50 to 200 gr (particles) per surface area. I have to wear it.

In this state, pour a predetermined amount of cement mortar C mixed with glass fibers in advance, or simultaneously spray cement mortar C and glass fibers, and cover the entire other surface of the cement mortar C on the lower surface. A filter 2 coated with a release agent in the same manner as described above, and an elastic membrane 3 whose shape is maintained approximately along the desired inner surface of the cement product by means of a perforated iron plate 4, for example, the thickness is in the range of 1 to 577 mm. The mold is clamped by pressing the upper formwork 1C with the rubber membrane attached to it in contact with one side of the poured or sprayed cement mortar C. During this mold clamping, the upper mold A mechanical strain force of 1 kg 10A or less is applied to the frame 1C, and further, preferably, the entire formwork 1 is subjected to vibration at a frequency of about 2 x 103 to 30 x 10'' per minute and a swing width of 0.1 to 2.
．． By applying mechanical vibrations of about 5 mm for 5 to 30 seconds, the fluidity of the cement mortar C is increased, and the cement mortar C is made to flow evenly throughout the formwork 1, and at the same time defoaming is performed.

In addition, the pressing speed of the upper formwork 1C is preferably within the range of 10 to 300 mm per minute, for example, 10100 r per minute.

Then, the upper formwork 1C is locked to the side formwork 1B by tightening the ports 5, and the assembled state as shown in FIG. 2 is obtained.

In this state, pressurized fluid is introduced into the back space of the elastic membrane body 3 within the formwork 1 through the hole 1d formed in the upper formwork 1C.
Preferably, a pressurized incompressible fluid, for example water, is introduced and the fluid pressure is applied to the elastic membrane 3 from the direction of the arrow to pressurize the cement mortar C and mold it. The cement mortar C is pressed against the frame surface, and the excess water in the cement mortar C is passed through the filters 2, 2 and the drainage holes 1b, lc, so that the moisture content of the cement mortar C is reduced to 10 to 15 (initial moisture content 15 to 25). It is dehydrated until it loses its fluidity and becomes able to self-retain a predetermined shape.

It is desirable to force drainage using a vacuum.

The maximum pressure in this case is 10 to 60 kg/crrt
For example, the rate of increase in pressure is within the range of 10 to 50 kg/ctA, preferably about 30 kglca per minute, and the rate of increase in pressure is preferably within the range of 30 kglca per minute. The time is within the range of 1 to 10 minutes, for example, approximately 3 minutes is appropriate.

Thereafter, by discharging the pressurized fluid, a negative pressure is generated at the contact surface between the uncured cement mortar C and the elastic membrane 3, and at this time, air, preferably air, is further discharged from the drainage hole 10 etc. If pressurized gas is introduced, a clearance corresponding to the dewatered volume will be formed between both C and 3, and at this time, at the interface between the filter 2 and the unhardened cement mortar C, Because of the presence of the remover, it is possible to easily remove only the filter 2 without adhering part of the cement mortar to the surface of the filter 2 (the adhesive force between the filter and the remover is relatively small, so
The filter is removed while the removal agent remains attached to the mortar surface.

) Therefore, the mold is removed without damaging the surface of the cement mortar C, or with very little damage, and the cement mortar C, which is in a self-retaining state, is allowed to cure and harden as it is.

The release agent) is attached to the surface of the hardened cement product in an embedded state, so it does not damage the appearance of the product.

After the demolding is completed, remove the mold plate and filter 2.
The elastic membrane body 3 can be cleaned by simple means such as washing with water and can be used repeatedly.

In addition, in view of the need for the above-mentioned example to be particularly effective in manufacturing three-dimensional products, the cement mortar poured into the formwork was stably spread throughout the interior. Flowable mix, i.e. aggregate/cement ratio (-8/
C) is 0.3 to 1.5, preferably 0.6 to 1.0,
Water/cement ratio (W/C) is 0.3 to 1.0, preferably 0.45 to 0.55 for premix, 0.35 to 0.145 for spray, and alkali-resistant glass fiber length is 10. It is desirable that the glass fiber content in the reinforcing cement product is 1% to 10%, preferably 2% to 5%, and even better fluidity can be obtained. Therefore, the ratio of fluidity imparting agent (thickener) such as methylcellulose to cement is 0.0005~
It is good to add about 0.02, preferably o, ooi to 0.004.

Further, the elastic membrane body may be in the form of a bag, and the elastic membrane body may be provided along the side formwork 1B and the bottom formwork 1, and a pressurized fluid for applying fluid pressure thereto may be provided. , it may be introduced from between the contact surfaces of the upper formwork and side formwork; in this case,
There is no need to use perforated iron plates for formwork.

Furthermore, as a pressurizing means for dewatering, mechanical press pressure may of course be used instead of the fluid pressure applied through the elastic membrane as in the above embodiment.

[Brief explanation of the drawing]

The drawings show an embodiment of the method for manufacturing a glass fiber reinforced cement product according to the present invention, and FIGS. 1 and 2 are longitudinal cross-sectional views for explaining the working procedure. 1...Formwork, 2...Filter, C.
...Cement mortar.

Claims (1)

[Claims] 1 After clamping the glass fiber-containing cement mortar C supplied in a formwork 1 which has a pressure-resistant structure and has a filter 2 for removing excess water on at least one of its inner surfaces, the cement mortar C is pressurized. By this,
The surplus water in this cement mortar C is filtered through the filter 2.
In a method for manufacturing a glass fiber reinforced cement product by dehydrating the cement mortar C until it can self-retain a predetermined shape through the filter, followed by demolding and curing, the filter is in contact with the poured cement mortar C. A method for producing a glass fiber-reinforced cement product, which comprises spraying a release agent made of fine particles on two surfaces.