KR101276166B1 - Autoclaved light weight concrete composition including the thermosetting resin - Google Patents

Abstract

The present invention relates to a lightweight foamed concrete composition containing a thermosetting resin, and more particularly, to a lightweight foamed concrete composition in which a thermosetting resin is mixed with a mixture of silica sand, quicklime and cement to improve physical properties such as strength of a product. According to the present invention, the thermosetting resin is included in an amount of 1.5 to 2.5% by weight based on the total weight of the composition obtained by mixing 0.04 to 0.05 parts by weight of aluminum powder and 6 to 7 parts by weight of distilled water with respect to 100 parts by weight of the cement mixture including cement, silica sand and quicklime. A lightweight foamed concrete composition containing a thermosetting resin added is disclosed.

Description

Light-weight foamed concrete composition containing thermosetting resin {Autoclaved light weight concrete composition including the thermosetting resin}

The present invention relates to a lightweight foamed concrete composition containing a thermosetting resin, and more particularly, to a lightweight foamed concrete composition in which a thermosetting resin is mixed with a mixture of silica sand, quicklime, and cement to improve physical properties such as strength of a product.

ALC (auto clave light weight concrete) is an industrialized product that makes blocks or panels. It is lightweight, porous, and hygroscopic. It has excellent insulation, scratches, and sound insulation, but is limited to use as a structural material. It is applied to exterior walls.

ALC (auto clave light weight concrete) is a kind of foam concrete that is light weight by dispersing countless bubbles in concrete by foaming agent independently. It is produced in the form of panel reinforced with reinforcement of blocks. It has excellent performance in phosphor light weight, heat insulation, fire resistance and workability.

ALC forms a slurry by mixing lime, siliceous raw material, foaming agent, and admixture with water as the main raw materials, and then forms structurally stable Tobermorite crystals through a steam wild process in an autoclave of high temperature and high pressure. It is manufactured by the process of forming.

In this process, the combination ratio of siliceous material and calcareous material is different for each ALC manufacturer, but there is no significant difference in physical and chemical properties of the material and product. Rather, the formulation of a suitable raw material for each manufacturing process is adopted. to be.

The present invention is applied to a thermosetting resin (Thermosetting Resin) to the ALC material in order to supplement the problems appearing when applying a high-strength concrete raw material to the ALC material lightweight containing a thermosetting resin that can secure the same or more properties than the conventional ALC It is a problem to provide a foamed concrete composition.

The lightweight foamed concrete composition containing the thermosetting resin of the present invention solved the above problems is 18 to 20 parts by weight of cement, 100 to 20 parts by weight of silica sand composed of sand slurries and return slury, lime 8 It is added to include 1.5 to 2.5% by weight of the thermosetting resin to the total weight of the composition of 0.04 to 0.05 parts by weight of aluminum powder, 6 to 7 parts by weight of distilled water with respect to 100 parts by weight of the cement mixture comprising 9 parts by weight. It is done.

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Here, the silica sand is characterized in that the sand slurry: the return slurry has a weight ratio of 1: 0.5 ~ 0.6.

Here, 20% NH 4 CL aqueous solution is added to the composition, characterized in that 2% by weight is further added relative to the amount of the thermosetting resin.

Here, the thermosetting resin is characterized in that the melamine resin or urea resin.

The lightweight foamed concrete composition containing the thermosetting resin according to the present invention has a thermosetting resin is bonded between Tobermorite in the same crystal phase to bring a crosslinking role to increase the strength of the molded body, lower the thermal conductivity to give a thermal insulation effect Has an excellent effect. In other words, by mixing the thermosetting resin in the ALC material, various physical properties of the lightweight foam concrete have the same or more enhancement effect than the conventional one.

1 is a photograph observing the state change after heating the molded body according to the content of the thermosetting resin of the composition according to the present invention.
Figure 2 is a graph showing the results of measuring the compressive strength and flexural strength according to the content of the thermosetting resin of the composition according to the present invention.
Figure 3 is a photograph comparing the microstructure of the molded article without the thermosetting resin added and the molded article according to the present invention.
Figure 4 is a XRD measurement graph according to the content of the thermosetting resin according to the present invention.
Figure 5 is a graph showing the expected result of the compressive strength by specific gravity of the composition according to the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS The present invention will be described in more detail with reference to the accompanying drawings.

The lightweight foamed concrete composition containing the thermosetting resin according to the present invention is added to the total weight of the composition by mixing 0.04 to 0.05 parts by weight of aluminum powder and 6 to 7 parts by weight of distilled water based on 100 parts by weight of the cement mixture including cement, silica sand and quicklime. It may be added so as to contain 1.5 to 2.5% by weight of the thermosetting resin.

The cement composition comprises 18 to 20 parts by weight of cement and 8 to 9 parts by weight of quicklime with respect to 100 parts by weight of silica sand, and the silica sand is composed of sand slurries and return slury. The sand slurry: the return slurry is preferably mixed so as to have a weight ratio of 1: 0.5 to 0.6.

According to the present invention, a 20% NH 4 Cl aqueous solution may be further added to the composition as a curing agent of the thermosetting resin by 2% by weight relative to the amount of the thermosetting resin added. By adding the aqueous solution it is possible to control the curing rate of the concrete during construction.

The thermosetting resin used in the present invention utilizes a property of increasing the degree of polymerization when the polymer of low molecular weight is heated and does not deform even when a large force is applied. That is, when heat is applied as a raw material of a liquid having a moderate viscosity in a low molecular weight mixture, cross-linking is formed, thereby forming a three-dimensional network structure. Therefore, even when a large stress is applied, it is not deformed, does not melt in the solvent, and does not melt even at elevated temperatures. Depending on the type of heat, some of them may recede or lose strength, but most of them will decompose or evaporate. In general, it has good heat resistance, solvent resistance, chemical resistance, mechanical properties, and electrical insulation, and it is possible to make a strong molding by adding a filler. It is also used in the manufacture of fiber reinforced plastics in combination with high strength fibers. Thermosetting resins are divided into condensation polymerization type and addition polymerization type, but phenol resin, urea resin, melamine resin may be exemplified in the condensation polymerization type, epoxy resin, polyester resin, etc. in the addition polymerization type, preferably melamine according to the present invention. It is recommended to use resin or urea resin.

In the present invention, by adjusting the blending amount of the melamine resin and urea resin in the ALC material as a thermosetting resin in the lightweight foamed concrete composition containing the thermosetting resin disclosed above, the ALC molded product was prepared, and then evaluated the basic properties and functionalities.

Basic measurement method is to cut the hydrothermally synthesized molded product into 160 (mm) size and dry it sufficiently until it becomes the quantity under dryer 100 condition.Measure specific gravity and bending strength, and cut it to 50 (mm) size. After drying under conditions, the compressive strength is measured. In addition, after cutting the molded body to the size of 200 (mm) and dried under the same conditions and measure the thermal conductivity. Observe the microstructure observation and XRD pattern according to the manufacturing conditions of the molded product.

end. Preparation of molded product and measurement of basic properties according to the content of thermosetting resin

In order to apply thermosetting resin to ALC material, it is assumed that silica, quicklime, and cement are 100% of the starting materials as powder raw materials, and the ratio of CaO / SiO ₂ which has a great influence on the strength of the product is currently applied. According to the standard formulation ratio was set.

Currently, the formulation used in the field uses sand slurry and return slurry, its solid content is calculated, and cement and small amount of quicklime are used. The blowing agent used aluminum powder 0.08% compared to the mixed powder, the mixing amount was fixed to 70% compared to the mixed powder (Raw Mix). To select the thermosetting resin and the content of the curing agent (20% NH ₄ Cl aqueous solution), control the content of the curing agent (0%, 2%, 4%, 6% compared to the thermosetting resin) as shown in Figure 1-23. After heating for 180-7 hours in an autoclave, the state change was examined. As shown in FIG. 1, when the thermosetting resin was heated, the urea resin was burned incompletely by burning in the autoclave. On the other hand, the melamine resin was found to be well preserved even when heated. In addition, when 2% of the curing agent was added to the melamine resin, it was confirmed that the state of the melamine resin hardened best after heating.

In order to fix the amount of curing agent at 2% of the thermosetting resin and to find the optimum mixing ratio of the thermosetting resin to be applied to the ALC material, control the amount of the resin to the foreign powder compared to the mixed powder, manufacture the molded body, measure the specific gravity, the compressive strength, the bending strength, and then optimize the The compounding ratio of was derived. The maximum temperature and holding time for hydrothermal synthesis were fixed at 180 -7 hours, and the hydrothermally synthesized molded parts were wet-cut to the appropriate size and subjected to constant drying to measure properties and evaluated. The blending design of the basic raw material and the thermosetting resin is shown in Tables 1 and 2 below. The unit is [g].

The melamine resin and urea resin of Tables 1 and 2 were added to the amounts shown in Tables 1 and 2 to the total amount of cement, quicklime, sand slurry, return slurry, aluminum powder and distilled water.

cement quicklime Sand slurry (d = 1.58) Return slurry (d = 1.35) aluminum
powder Distilled water Melamine resin
(weight%) 1060 470 3541 1984 4.2 630 0 1060 470 3541 1984 4.2 630 2 1060 470 3541 1984 4.2 630 4

To the composition of Table 1, a 20% NH ₄ Cl aqueous solution was added as a curing agent to the melamine resin content (total amount of melamine resin [g] × 2%).

cement quicklime Sand slurry (d = 1.58) Return slurry (d = 1.35) Aluminum powder Distilled water Urea Resin
(weight%) 1060 470 3541 1984 4.2 630 0 1060 470 3541 1984 4.2 630 2 1060 470 3541 1984 4.2 630 4

To the composition of Table 1, 20% NH ₄ Cl aqueous solution was added to the amount of urea resin [g] × 2% as a curing agent relative to the urea resin content.

The hydrothermally synthesized molded body is cut to a size of 160 (mm) to measure the bending strength and dried sufficiently until it becomes a quantity under 100 conditions of a dryer. In addition, the molded body is cut to a size of 50 (mm), dried under the same conditions, and then measured for specific gravity and compressive strength. Specific gravity of the specimen was measured by the volume specific gravity including the open pore and the results are shown in Table 3. The unit is [g / cm 3].

Remarks Melamine resin Urea resin 0% 2% 4% 0% 2% 4% Weight ratio 0.48 0.47 0.46 0.48 0.47 0.46

When the melamine resin and the urea resin were added, the specific dry weight ranged from 0.46 g / cm ³ to 0.47 g / cm ³ , and the difference was not large. As in the previous experiments, the compressive strength tester was used for the test piece used to measure the dry weight, and the compressive strength was measured according to the content of the thermosetting resin, and the bending strength was measured for the test piece of 160 (mm). One result is shown in Table 4 and accompanying drawings. The unit is [MPa].

Remarks Melamine resin Urea resin 0% 2% 4% 0% 2% 4% Compressive strength 3.70 5.06 4.71 3.70 4.97 4.65 Flexural strength 1.48 2.89 2.48 1.48 2.75 2.34

The compressive strengths varying from 4.65 MPa to 5.06 MPa vary depending on the content of the thermosetting resin. The compressive strength of the thermosetting resin was about 26.88% when compared to the molded article without the thermosetting resin. It is believed that the thermosetting resin is bonded between Tobermorite during the hydrothermal synthesis of the ALC material, thereby acting as a crosslinking agent to absorb and disperse the load. This is well illustrated in the scanning electron micrograph of FIG. 3.

Referring to the microstructure photograph of FIG. 3, in the case of the molded article to which the thermosetting resin was not added, regular formation of Tobermorite was confirmed, but it was determined that the hexagonal plate shape was formed long to adversely affect the strength development. However, in the case of the molded article to which the thermosetting resin was added, the thermosetting resin was bonded between the Tobermorite in the pores, and when the thermosetting resin was loaded, it was considered to have exhibited elasticity and absorbed and dispersed the load. However, as shown in the compressive strength results table, an excessive amount of thermosetting resin (4%) was found to adversely affect the strength development.

Figure 4 is an analysis of the XRD Pattern according to the content of the thermosetting resin. The formation of Tobermorite and the presence of other crystal phases were investigated through XRD pattern analysis of the molded article without the thermosetting resin and the molded article containing the melamine resin and the 2% urea resin.

As a result of measuring the formation of Tobermorite through XRD measurement, it was found that the same Tobermorite and Quartz were formed in all specimens. In other words, the thermosetting resin is bonded to Tobermorite in the same crystal phase, and the crosslinking role is considered to have the effect of enhancing the strength of the molded body.

I. Functional measurement and evaluation according to the content of thermosetting resin

The thermal insulation mechanism of the material can be explained mainly by the influence of phonons and photons,

As the conduction of phonons (energy particles that make up lattice waves, etc. inside solids) and photons (mainly negligible values that are very small compared to phonons, which are particles with a certain value of energy and momentum, usually considered in gases) This is known to be excellent. In particular, air exhibits lower thermal conductivity than solids due to its low heat capacity, and in the case of a gas having low thermal conductivity (for example, gas in pores), the thermal conductivity (K) has a difference in the concentration of gas molecules (C) and energy balance due to collision between molecules. It is proportional to the mean distance between collisions under the conditions established, that is, the mean free path L and the mean velocity V of the gas molecules. (K = (1/3) CVL) In the present invention, the experiment was carried out using a thermal conductivity tester (HC-074, EKO, Japan) to which the plate heat flow method was applied, and the test specimen was manufactured to a size of 200 (mm). , Thermal conductivity measurement results are shown in Table 5. According to the results, 0.118W / mK without thermosetting resin, 2% and 4% with urea resin, 0.105W / mK, 0.098W / mK and 4% with melamine resin were added, respectively. In all cases, 0.098 W / mK was observed, and it was found that the thermal conductivity was lowered when the thermosetting resin was added. This is determined that the thermosetting resin bonded to the ALC material exhibits the effect of absorbing heat and lowering the thermal conductivity, similar to the compressive strength.

Remarks Melamine resin Urea resin 0% 2% 4% 0% 2% 4% Thermal conductivity 0.118 0.098 0.098 0.118 0.105 0.098

The unit of Table 5 is [W / mK].

All. Comparison and Evaluation of High Strength Concrete Raw Material and Thermosetting Resin According to ALC Application

The results of the measurement of dry weight and compressive strength according to ALC application of high strength concrete raw material and thermosetting resin are shown in Table 6 below.

Dry weight (g / cm ³ ) Compressive strength (MPa) High strength concrete raw material 0.86 14.4 0.83 15.6 0.74 8.21 0.72 7.92 0.55 3.32 0.54 3.11 Thermosetting resin 0.52 3.18 0.48 4.00 0.47 5.06 0.46 4.71 0.47 4.97 0.46 4.65

Looking at the above experimental results, when the high-strength concrete raw material is applied to the ALC material, it can be seen that the strength increase and decrease rate is significantly different based on the specific gravity of about 0.70 g / cm ³ .

That is, specific gravity 0.70g / cm ³ when the production of ALC or more high-boiling material is applied to high-strength concrete material in the ALC materials can be produced molded products of good quality, but, on the contrary density 0.70g / cm ³ or less ALC low specific gravity of the material during manufacture, the The application of high strength concrete raw materials is inadequate. In addition, when the thermosetting resin is applied to the production of low specific gravity ALC materials of about 0.70 g / cm ³ or less, high-quality molded bodies can be produced. On the contrary, the application of the thermosetting resin when the high specific gravity materials of 0.70 g / cm ³ or more is manufactured. This means that it is inappropriate.

The expected degree of compressive strength by specific gravity is shown in FIG. 5.

Claims (5)

Aluminum powder 0.04 to 0.05 with respect to 100 parts by weight of the cement mixture including 18 to 20 parts by weight of cement and 8 to 9 parts by weight of quicklime, based on 100 parts by weight of silica sand consisting of sand slurries and return slury. Lightweight foamed concrete composition containing a thermosetting resin, characterized in that the addition of urea resin 1.5 to 2.5% by weight based on the total weight of the composition by mixing by weight, 6 to 7 parts by weight of distilled water.
delete The method of claim 1,
The silica sand is a light weight foam concrete composition containing a thermosetting resin, characterized in that the sand slurry: the return slurry has a weight ratio of 1: 0.5 ~ 0.6.
The method of claim 1,
Lightweight foamed concrete composition containing a thermosetting resin, characterized in that the 20% NH 4 CL aqueous solution is added to the composition 2% by weight relative to the addition amount of the thermosetting resin.
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