JPH0216275B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Application Field] The present invention relates to a surface material interposed between a boat or panel and a cement concrete surface, which is used for the outer wall, inner wall, partition wall, etc. of a building during residential construction using the cement concrete pouring method. More specifically, it relates to a surface material that can firmly adhere to a cement concrete surface. [Conventional techniques and their problems] In recent years, from the standpoint of energy consumption or livability, emphasis has been placed on heat insulation construction and soundproof construction when constructing houses using the cement concrete pouring method. In such insulation and sound construction,
Panels and boards (hereinafter collectively referred to as boards) made of inorganic materials such as rock wool, slag wool, and glass fiber, or organic materials such as expanded polystyrene, expanded polyethylene, and expanded polyurethane are bonded to the cement concrete surface. The method is commonly used. A surface material laminated with a polyethylene film is attached to the surface of these boards for adhesion between the board surface and the cement concrete surface and for waterproofing. The characteristics required of the surface material for adhering the board surface and cement concrete surface are (1) strong adhesion to the cement concrete surface, (2) good dimensional stability, 3) It is waterproof. In particular, since the cement concrete and the facing material need to be integrated after construction, the selection of the facing material is very important. Conventionally, asbestos sheets or sheets mainly made of inorganic fibers coated with adhesive have been used as surface materials for boards. However, asbestos does not necessarily have sufficient adhesion to cement concrete, and furthermore, it is harmful to health because it causes respiratory diseases. In particular, there is a risk of inhaling asbestos fiber powder during the manufacture and construction of board products, which is unfavorable in terms of the working environment. In addition, asbestos is produced only in limited areas, making it unstable in price and difficult to obtain.
Further, a sheet mainly made of inorganic fibers coated with an adhesive has the disadvantage of poor flexibility and poor adhesion to cement concrete. [Purpose of the Invention] Therefore, the present inventors conducted various studies to develop new and improved facing materials in place of the conventional facing materials as described above, and based on the experimental results described below, It has been possible to develop a face material made of the inorganic sheet of the present invention, which has good adhesion to the inorganic sheet and can provide high adhesive strength. [Means for Solving the Problems] Experimental examples conducted by the present inventors and the results obtained will be explained below. Pulverized limestone powder (average particle size 15μm)
and beaten cellulose pulp in a predetermined amount, suspended in water, added a small amount of polyvinyl alcohol and a sizing agent, and then made into paper by hand.
Sheets with a thickness of 0.2 mm were obtained with varying amounts of limestone powder. After laminating polyethylene with a thickness of 30 μm on one side of this sheet, hard polyurethane was poured onto the laminated surface to a thickness of about 20 mm, heated to foam, and then solidified. In this way, a rigid foamed polyurethane board was produced using an inorganic sheet as a face material in which limestone powder was uniformly fixed and supported on cellulose pulp. Next, this board was cut into a disk shape with a diameter of 50 mm, and the inner diameter was 50 mm and the height was cut with the inorganic sheet facing upward.
Place it on the bottom of a 100mm metal cylindrical formwork. Cement mortar, which had been mixed and prepared in advance, was poured into this mold and solidified, thereby producing a cylindrical test piece in which the board and cement mortar were joined via an inorganic sheet facing material. From pouring cement mortar to demolding, the temperature is 20℃±1℃ and the humidity is 80%.
The test specimen was left standing in a constant temperature and humidity chamber for 24 hours, and the test specimen was cured at a temperature of 20°C and 1°C, and a humidity of 80%. In addition, the cement mortar composition is ordinary Portland cement.
520 parts by weight of standard sand, 1040 parts by weight of standard sand, and 338 parts by weight of water, and the mortar was mixed in accordance with JIS R5201. An adhesive strength test of the test piece prepared above was conducted using an Instron type automatic testing machine, and a 90 degree tensile load of 10 mm/min was applied to the test piece to peel the board from the cement mortar surface. The load was measured. The graph in the attached drawing shows the measurement results, and shows the relationship between the limestone powder content in the inorganic sheet of the face material and the inorganic sheet-cement mortar bond strength (28-day strength).
From this graph, it can be seen that as the limestone powder content in the sheet increases, the adhesive strength increases, and good adhesive strength between the inorganic sheet and cement mortar can be obtained in the range of 60 to 95% by weight without limestone powder. I understand. In addition, when examining the releasability of the inorganic sheet-cement mortar adhesion surface of test specimens, it was found that in the case of inorganic sheets containing 60 to 95% by weight of limestone powder, the sheets themselves were torn uniformly over the entire surface. , delamination occurred uniformly in a state where one half of the sheet thickness was adhered to the cement mortar surface and the other half was adhered to the board surface. On the other hand, those using inorganic sheets with a limestone powder content of less than 60% by weight do not exhibit uniform delamination as described above, and the entire thickness of the sheet partially adheres to the cement mortar surface or board surface. In addition, when an inorganic sheet with a limestone powder content of 45% by weight or less was used, the sheet peeled off from the cement mortar surface while the entire thickness of the sheet remained adhered to the board surface. From these results, the limestone powder content is 60
It was found that the ~95% by weight inorganic sheet had very good adhesion to cement mortar.
Furthermore, these phenomena were observed not only in sheets using limestone powder, but also in inorganic sheets using other inorganic powders such as blast furnace slag, which will be described later. The present invention was completed based on the above findings. In other words, the inorganic sheet for bonding cement to concrete of the present invention contains 60 to 95% by weight of an inorganic powder containing one or more of calcareous, magnetic, or silicic components that easily react with cement paste, and cellulose fibers as the main component. It is characterized by being made of a sheet-like material in which 5 to 40% by weight of a fibrous material is fixed and supported. [Function] The inorganic sheet of the present invention having the above-described structure is interposed between the board and the cement concrete surface as a face material of the board in the cement concrete pouring method. Thus, according to the inorganic sheet of the present invention, by using an inorganic powder that easily reacts with cement paste as the powder fixed and supported on the fibrous material mainly composed of cellulose fibers, it is stable at the interface with the cement paste in the cement concrete pouring method. Forms a chemically reactive layer that provides strong adhesion. In addition to the above-mentioned limestone, the inorganic powder used in the present invention includes dolomite, light calcium carbonate, light magnesium carbonate, hydroglossor (3CaO・Al ₂ O ₃・6H ₂ O), ettringite, blast furnace slag, and fly ash. Examples include powders such as , activated clay, and acid clay. In other words, natural or artificial inorganic powder containing one or more of calcareous, magnesic, or silicic components that easily react with cement paste can be used as the inorganic powder in the present invention. The inorganic sheet containing these inorganic powders forms a stable chemical reaction layer at the interface with the cement paste to obtain a strong adhesive state.
For example, when limestone is used as an aggregate in cement concrete, it is recognized that it has good adhesion to the cement, and when limestone is mixed in powder form, CaO・3Al ₂ O ₃ in the cement reacts with the limestone. It is known that calcium carboaluminate hydrate is produced and has a strength-enhancing effect. Blast furnace slag usually contains CaO38~42%, _SiO2 30~50%
%, Al ₂ O ₃ 13 to 19%, and MgO 3 to 6%. Because the mineral composition is glassy, it stores crystallization energy internally and has strong latent hydraulic properties. That is, when blast furnace slag comes into contact with water,
CaO・_SiO2 is eluted to form a dense hydration product, and the alkaline stimulant from the cement causes CaO−
Hydration products such as SiO ₂ -Al ₂ O ₃ ·n H ₂ O are formed and solidification progresses. In addition, fly ash and activated clay have porazon reactivity, in which the soluble silicates contained therein combine with Ca(OH) ₂ liberated in cement concrete. The fibrous materials used in the present invention are mainly cellulose fibers such as paper pulp, but may also include rayon fibers, synthetic fibers such as PVA, polyester, polyamide, polyolefin, vinyl fibers, and Mineral fibers such as rock wool and glass fibers can also be used as long as they are mainly blended with cellulose fibers. Cellulose fibers are not particularly limited, but in order to enhance the fixing effect of the inorganic powder to the fibers and increase the physical strength of the inorganic sheet, long-fiber natural cellulose pulp may be cationically modified to a low degree and then beaten. It is preferable to use the resulting cationically modified pulp. As can be seen from the above-mentioned experimental examples, good adhesive strength with cement concrete can be obtained when the content of the inorganic powder in the inorganic sheet is in the range of 60 to 95% by weight. If it is less than 60% by weight, the adhesive strength between the cement concrete and the sheet will be weak, and when the adhesive surface between the sheet and the cement concrete is peeled off, the sheet itself will not exhibit uniform delamination properties. On the other hand, when the amount exceeds 95% by weight, uniform delamination properties of the sheet itself are observed when the adhesive surface between the sheet and cement concrete is peeled off.
In addition, although the adhesiveness between the sheet and cement concrete is good, the lack of fibrous components in the sheet makes the sheet material weak, making it difficult to handle as a facing material and impractical. When manufacturing the inorganic sheet of the present invention,
A method can be adopted in which a fibrous material and an inorganic powder are mixed in a predetermined ratio to form an aqueous suspension, and this is then made into paper using a normal paper making method. The inorganic sheet thus obtained is paper-like in which fine inorganic particles that easily react with cement paste are uniformly adsorbed and supported in the fibrillar structure of cellulose fibers, and the thickness can be freely adjusted depending on the purpose of use. . As explained above, the present invention is an inorganic sheet in which inorganic powder, which easily reacts with cement paste and is generally available, is uniformly fixed and supported on cellulose fibers, and this is bonded to the cement concrete surface using the cement concrete pouring method. When used as a facing material for the surface of a cement board, a stable chemical reaction layer is formed at the interface with the cement paste, resulting in a strong adhesion, resulting in a strong bond with the cement concrete surface and a high adhesive strength. can be obtained. In addition, it can be manufactured using the normal wet papermaking method for papermaking, and by effectively utilizing the fibrillar structure of cellulose fibers, it is possible to fix and carry inorganic powder that easily reacts with cement paste. Good and easy to manufacture. [Examples] The present invention will be further explained below with reference to Examples. Blast furnace slag, fly ash, and activated clay were each pulverized into powders with an average particle size of 15 μm. These powders were mixed into beaten cellulose pulp (beaten to a water content of 200mlC.SF) and glass fiber (FCS31-33 manufactured by Nippon Electric Glass Co., Ltd., diameter 9.9μ,
3 mm in length) to make a water suspension, add a small amount of polyvinyl alcohol and a sizing agent, and then make paper by hand to a thickness of 0.2 mm.
Three types of inorganic sheets with an inorganic content of 75% by weight were prepared. The amount of glass fiber mixed was 15% by weight of the cellulose pulp. Next, a rigid polyurethane foam board using these inorganic sheets as the facing material was prepared in the same manner as in the experimental example described above, and a cylindrical test specimen was also created in which the board and cement mortar were bonded via the inorganic sheet facing material. . For each of the three types of test specimens obtained in this way, the inorganic sheet-cement mortar adhesive strength (7-day strength and 28-day strength
The results of measuring the daily intensity are shown in the table below. For comparison, a similar test specimen was prepared using an asbestos sheet (thickness: 0.23 mm), which has been conventionally used as a facing material, and the results of measuring the adhesive strength are also listed.

[Table] From the above table, it can be seen that the adhesive strength of the inorganic sheets of the present invention with cement mortar is higher than that of asbestos sheets, and the inorganic sheets of the present invention are firmly bonded to the cement mortar surface. Furthermore, as a result of examining the releasability of the adhesive surface between the inorganic sheet and the cement mortar, the sheets themselves were torn uniformly over the entire surface in both cases, indicating good interlayer releasability.

[Brief explanation of drawings]

The attached drawing is a graph showing the relationship between the limestone powder content and the sheet-cement mortar adhesive strength for an inorganic sheet using limestone powder as the inorganic powder.

Claims (1)

[Claims] 1. 60-95% by weight of an inorganic powder containing one or more of calcareous, magnesic, or silicic components that easily react with cement paste is fixed in 5-40% by weight of a fibrous material mainly composed of cellulose fibers. An inorganic sheet for bonding cement to concrete, characterized by being made of a supported sheet material.