JPS5844623B2 - Glass Senikiyouka Cement Seihin - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to glass fiber reinforced cement products that have high strength over long periods of time.

Conventionally, various methods of reinforcing cement matrices with glass fibers have been attempted, but cement matrices such as Portland cement and alumina cement are strongly alkaline (PH = 12 or higher), and they cannot be used under such strong alkaline conditions. However, it was considered undesirable to use glass fiber as a reinforcing material because of the severe deterioration of glass fiber.

In particular, FRP (glass fiber reinforced plastics)
E-glass fiber, which is widely used in the industry, suffers from severe deterioration, and E-glass fiber-reinforced cement products are impractical because their strength decreases in a short period of time.

Recently, attempts have been made to reinforce the cement matrix with alkali-resistant glass fibers containing ZrO2 or TiO2 as glass components, but even in this case, the long-term strength (150 days or more) tends to decrease.

The present inventors conducted various studies regarding the alkali deterioration rate of glass fibers and the strength of glass fiber reinforced cement products, and as a result, the following facts became clear.

(-'0 As the cement matrix hardens, its strong alkalinity tends to become slightly weak (PH=
10-11).

(b) When curing at room temperature, if the strong alkalinity of the cement matrix is made weakly alkaline to pH=10 to 11 in 2 to 3 days, the glass fiber reinforced cement product will hardly lose its strength over a long period of time.

←→ During high-temperature curing at 50℃ or higher, the strong alkalinity of the cement matrix can be reduced to PH=10~ within about 20 hours.
When alkalized to 11, the glass fiber reinforced cement product hardly loses its strength over a long period of time.

In view of the above facts, the present inventors have determined that the strong alkalinity of the cement matrix can be increased by 50% in 2 to 3 days when cured at room temperature.
In case of high temperature curing above ℃, pH = 10 within about 20 hours.
Various additives were added to make it weakly alkaline in the range of ~11L.
・As a result of our investigation, we found that the above-mentioned weak alkalization can be achieved by incorporating at least one or two selected from volcanic ash-denatured non-grade aluminosilicate, acid-treated clay, or amorphous silica gel into the cement matrix. I discovered something.

In addition, various pozzolans other than the above four types are known to cause a weak alkalization reaction (pozzolanic reaction) in the cement matrix and are effective in improving long-term strength, such as bentonite, kaolin, and white carbon. , fly ash, glass powder, perlite, quartz powder, etc., were found to be unable to make the cement matrix weakly alkaline in a short period of time as described above.

In addition, by incorporating at least one type selected from volcanic ash-denatured non-quality aluminosilicate, acid-treated clay, and amorphous silica gel into the cement matrix,
It has been discovered that E-glass fiber whose surface has been treated with an alkali-resistant synthetic resin, which has been considered unsuitable as a reinforcing material for cement matrices, can be used as a reinforcing material.

The cement matrix used in the glass fiber reinforced cement product of the present invention is mainly composed of hydraulic cement such as Portland cement and alumina cement with a high alkali content, and various cements may be mixed with these cements as necessary. Blend materials (organic polymers, fillers, curing accelerators, water reducing agents, foaming agents, expansion materials, etc.).

The amount of at least one selected from volcanic ash modified non-grade aluminosilicate, acid-treated clay, and silica gel as a weak alkalizing agent for the cement matrix varies depending on the cement matrix system used.

For example, for a cement matrix whose main component is portland cement, **10 to 60 parts by weight per 100 parts by weight of the cement matrix, and for a cement matrix whose main component is alumina cement, 5 to 20 parts by weight per 100 parts by weight of the cement matrix. It is preferable to mix 1 part.

Examples of the volcanic ash-denatured non-grade aluminone licade used as the weak alkalizing agent of the present invention include Mokagami and Kanumagami.

The reason why it is possible to slightly alkalize in a short time by blending these volcanic ash modified non-grade aluminosilicates is that these aluminosilicates are very active and harden by hydration of Neelite, Beelite, etc., which are hardening components in the cement matrix. This is thought to be due to the reaction in a short period of time with the calcium hydroxide produced by the process, forming a type of calcium silicate gel.

The same can be said of the weak alkalizing effect of silica gel or acid-treated clay.

Particularly desirable acid-treated clays have a total content of alkali metals and alkaline earth metals of less than 5% by weight.

As the glass fiber used in the glass fiber reinforced cement product of the present invention, E glass fiber is used.

The blending amount of the above E glass fiber is cement matrix 1
It is desirable that the amount is 30 parts by weight or less.

This is because even if more than 30 parts by weight is blended, the contribution to the reinforcing effect will be small, making it difficult to mix with the cement paste.

The present invention will be explained below with reference to Examples.

Example 1 Mokagami Na 20 pulverized to 200-400 meshes in 100 parts by weight of Portland paste with a water/cement ratio of 0.4.
After adding 15 parts by weight of E glass fiber to which 10.3% by weight of styrene-butadiene rubber was attached and 2 parts by weight of calcium chloride and kneading them well, they were placed between two iron plates with a load of 50? /crA, temperature 20℃, humidity 6
A glass fiber reinforced cement board is created by curing at 0%.

The relationship between the number of days for curing and strength of this board is shown in the table below.

From the table above, it can be seen that the matrix of the glass fiber reinforced cement board containing Mokagami becomes weakly alkaline to PH = 10 to 11 in 2 to 3 days, has high long-term strength (28 days or more), and hardly deteriorates.

The 7-day bending strength of the glass fiber-reinforced cement board made under the same conditions as in the above example without adding Mokagami was 138 kg/ca (matrix PH = 13.3).
The bending strength on the 28th day was very small at 72 kg/crA (matrix PH = 13.3), and the strength decreased significantly.

This is E
This indicates that the glass fiber is severely degraded.

**Example 2 Alumina cement paste 10 with a water/cement ratio of 0.4
0 parts by weight, 10 parts by weight of Kanuma soil crushed into 200-400 meshes, 10 parts by weight of E glass fiber to which 11.2% by weight of styrene-butadiene rubber was attached, 2 parts by weight of barium acetate, and 4 parts by weight of zinc sulfate. After kneading, add 5 parts by weight of β-hemihydrate gypsum, apply a scissor load of 50 ft/crA between two iron plates, and heat at 60°C and humidity 8.
A glass fiber reinforced cement board is created by curing at 0%.

The relationship between the number of days for curing and strength of this board is shown in the table below.

From the above table, it can be seen that the matrix of the glass fiber reinforced cement board containing Kanuma soil becomes weakly alkaline to pH=10 to 11 within 20 hours, and its long-term strength (28 days or more) is high (and hardly decreases).

The 150-day bending strength of a glass fiber reinforced cement board made under the same conditions as in the above example without adding Kanuma soil was 102 kg/c4 (matrix pH = 12.2).
And small.

Example 3 100 parts by weight of Voltland cement paste (phase) with a water/cement ratio of 0.4, 20 parts by weight of acid-treated white clay (Futatsukanite, a product of Nippon Kousaku Hakudo Co., Ltd.), and styrene-butadiene rubber. Add 10 parts by weight of E-glass fibers with 10.3% adhesion and cut to 137 ILm, and 300 parts by weight of 30 to 50 mesh river sand, mix well, and then apply a scissors load of 501/crlt between two iron plates. , temperature 20
A glass fiber-reinforced cement board was prepared by curing at 60% humidity.

The relationship between the number of days for curing and strength of this board is shown in the table below.

From the table above, the matrix of E glass fiber reinforced cement board mixed with acid-treated white clay has a pH of 10 to 10 in 2 to 3 days.
It can be seen that the strength becomes weakly alkaline up to 11, the long-term strength (28 days or more) is high, and there is almost no decline.

The bending strength of the E-glass fiber reinforced cement board made under the same conditions as in the above example without adding acid-treated clay was as high as 195 kg/cyst in 7 days, but it was 195 kg/cyst in 28 days.
85kg/crrt, 76ky/crA in 150 days
and rapidly declined.

Example 4 To 100 parts by weight of alumina cement paste with a water/cement ratio of 0.35, 50 parts by weight of styrene-butadiene rubber latex (40% solids), 10 parts by weight of silica gel with a mesh size of 200 to 400, Add 15 parts by weight of E-glass fibers to which 9.85% by weight of styrene-butadiene rubber has been added and cut into 6 pieces, 2 parts by weight of barium oxalate, 2 parts by weight of ammonium sulfate, and 10 parts by weight of β-hemihydrate and mix well. After that, the scissor load between the two iron plates is 50 y7=
is added and cured at a temperature of 20°C and a humidity of 60% to create an E-glass fiber reinforced cement board.

The relationship between the number of days for curing and strength of this board is shown in the table below.

From the above table, it can be seen that the matrix of the glass fiber reinforced polymer cement board containing silica gel becomes weakly alkaline to pH 10-11 in 2 days, has high long-term strength (28 days or more), and hardly deteriorates.

Claims (1)

[Claims] 1 The main components are (a) cement matrix and (b)
) E glass fiber, and (c) a glass fiber having high strength over a long period of time, characterized by consisting of at least one kind selected from volcanic ash-denatured non-grade aluminone licade, acid-treated clay, or silica gel. Reinforced cement products.