KR101281986B1 - A Eco Friendly Loess Mortar - Google Patents

Abstract

The present invention relates to environmentally friendly mortar, and more specifically, it relates to the use of yellow clay as a substitute for cement, which is environmentally friendly, Resistance and tensile resistance of the mortar.

Description

{Eco Friendly Loess Mortar}

The present invention relates to environmentally friendly mortar, and more specifically, it relates to the use of yellow clay as a substitute for cement, which is environmentally friendly, Resistance and tensile resistance of the mortar.

Recently, yellow loose binders used as part of low carbon eco-friendly materials have been studied and used as substitutes for part or all of cement. Various studies have been conducted to achieve similar levels of performance of general cement in order to achieve eco-friendly effects by replacing cement with ocher.

However, conventional mortar (concrete) using yellow clay has lower compressive strength, higher drying shrinkage, lower work performance at the time of construction, lower freeze-thaw resistance and lower tensile resistance than general cement concrete. Especially, the deformation due to high shrinkage and the low tensile resistance cause cracks in the inside and outside, which may cause durability degradation. In order to control such deformation due to high shrinkage and low tensile strength, many techniques have been proposed to improve the resistance to cracking by using yellow clay as a binder and reinforcing organic fibers or steel fibers.

The technique of adding and reinforcing the fibers is effective in improving the bending strength and tensile strength by the strong elasticity of the fiber itself, and particularly improving the crack resistance by controlling the drying shrinkage.

However, most of the organic fiber composites consist of organic compounds. In particular, toxic gas generated from organic compounds in the case of fire is causing the problem of harmfulness. In the case of steel fiber, corrosion occurs and the corrosion .

Accordingly, in order to solve the above-mentioned problems, the present invention provides a yellow mortar which is environmentally friendly and can improve tensile resistance and crack resistance by adding lignocellulosic fibers, which are inorganic fibers, to yellow loam.

The mortar of the present invention comprises yellow soil as a binding material, and the lyocell fiber is reinforced with 0.6 to 2.4 kg / m3.

Also, the environmentally friendly yellow mortar satisfies f _{sp -v /} f _{sp -n} > 1.4, f _{sp -v} corresponds to the tensile strength value at the time of splitting in the yellow mortar specimen containing the lyocell fiber, and f _{sp- n} is characterized by a tensile strength value at the time of splitting in a yellow mortar specimen not containing a lyocell fiber.

Further, the eco-friendly yellow mortar has the following formula: f _{r -v /} f _{r -n} > 1.2, f _{r -v} corresponds to the flexural strength value at the time of fracture in the yellow mortar specimen including the lyocell fiber, f _{r -n} corresponds to the flexural strength value at the fracture at the loam mortar specimen without the lyocell fiber .

On the other hand, the eco-friendly mortar is characterized in that the initial crack occurs in excess of 1.5 days.

Wherein the initial crack and the crack width include a circular inner mold, a circular outer mold spaced apart from the outer periphery of the inner mold by a predetermined distance, a silicone seal sealing the inner mold and the upper surface opened by the outer mold, And is measured by a ring-shaped constrained drying shrinkage measuring apparatus constituted by at least one strain gauge attached to the mold.

In addition, the yellow soil mortar is environmentally _{friendly, 0.25 <P sca -v / P} sca -n < 0.7, and satisfies, P _sca-v is to the value in the crack area in the yellow soil mortar that contains lyocell fiber, P _{sca - n} corresponds to the crack area value in the yellow mud mortar containing no lyocell fiber.

Here, the crack area is measured as a crack area derived from a plate-shaped constrained drying shrinkage measuring device comprising a housing having an opened upper surface and one or more crack inducing parts protruding in one direction from the lower surface of the housing.

The mortar of the present invention has an advantage of improving the crack resistance by adding the lyocell fiber while using the loess as a binder.

In addition, the mortar of the present invention has an advantage of improving the tensile resistance by adding lyocell fibers while using loess as a binder.

Further, the present invention has an advantage of being environmentally friendly by using yellow clay as a binder and adding an inorganic material, lyocell fiber, for improving crack resistance and tensile resistance.

1 is a graph showing the relationship between the amount of added lyocell fibers and the rate of increase in tensile strength,
2 is a graph showing the relationship between the addition amount of the lyocell fibers and the bending strength increase rate,
3 is a graph showing the relationship between the added amount of lyocell fiber and initial crack,
4A and 4B are schematic views showing a ring-shaped constrained drying shrinkage measuring apparatus,
5 is a graph showing the relationship between the added amount of lyocell fiber and the crack area,
6A and 6B are schematic views showing a plate constrained drying shrinkage measuring apparatus.

Hereinafter, specific embodiments of the mortar of the present invention will be described with reference to the drawings.

The mortar of the present invention contains loess as a binder and a technique for improving the crack resistance and tensile resistance by adding lyocell fiber which is an inorganic material in order to improve crack resistance and tensile resistance which are disadvantages of such loess present.

More specifically, the mortar of the present invention comprises loess as a binder, and part or all of the loess mortar contains loess as a cement substitute.

In the present invention, the yellow loess that is included as a binder in the present invention is generally composed of at least one selected from the group consisting of SiO ₂ , Al ₂ O ₃ , CaO, K ₂ O, MgO, Na ₂ O) are uniformly distributed, and it is known that they are environment-friendly materials such as absorption power, self-tacking power, and far-infrared radiation. When using this environmentally friendly loess as a binder, the adhesive strength is lower than that of the cement, as described above, and the resistance to drying is low, and the drying shrinkage is higher than that of the cement.

In order to solve such problems, the lyocell fiber is added in the present invention, and the lyocell fiber is an environmentally friendly material that can be naturally incinerated as a cellulosic material which is an inorganic material. In addition, since the lyocell fiber has hydrophilicity, when the loess is used as cement as the binder, the adhesion of the cement paste to the cement paste by the hydrogen bonding can be enhanced, and the durability of the structure formed by the cement mortar is complemented.

In the present invention, the added amount of the lyocell fiber is limited to 0.6 to 2.4 kg / m3. When the addition amount of the lyocell fiber is less than 0.6 kg / m 3, the tensile strength performance, that is, the tensile strength and the bending strength are lowered, and the crack resistance is not improved by the trace amount, Lt; 3 &gt;, the dispersibility is not smooth and the workability is lowered, and the tensile resistance performance is decreased due to interlaminar aggregation or the like, and the partial crack resistance is deteriorated due to the distribution of non-uniform fibers on the crack surface.

On the other hand, in the case of the mortar of the present invention, it is appropriate to limit the tensile strength of fullerene mortar so that the value of f _{sp-v /} f _sp-n exceeds 1.4 as shown in FIG. f _{sp -v} corresponds to the tensile strength at the time of splitting at the loam mortar specimen containing the lyocell fiber and f _{sp -n} corresponds to the tensile strength at the splitting at the loam mortar specimen without lyocell fiber .

As shown in Fig. 1, this limitation shows that the addition amount of the lyocell fiber exhibits the most excellent tensile strength at 0.6 kg / m &lt; 3 &gt;, and addition of more than 2.4 kg / m &lt; It is economical and may cause problems such as a decrease in dispersion due to excessive addition. As a result, it can be seen that the optimum amount of addition in terms of tensile strength is 0.6 to 2.4 kg / m 3, It can be seen that the strength appears.

On the other hand, in the case of the mortar of the present invention, it is proper to limit the value of f _{rv /} f _rn to more than 1.2 in the bending strength as shown in Fig. f _{r -v} corresponds to the flexural strength value at the time of destruction of the yellow mortar specimen including the lyocell fiber, and f _{r -n} corresponds to the flexural strength value at the destruction at the yellow mortar specimen without the lyocell fiber.

Also, as shown in FIG. 2, it can be seen that the addition amount of the lyocell fiber exhibits the best bending strength at 0.6 kg / m 3, and addition of more than 2.4 kg / m 3 is insufficient in the bending strength and is not economical , And a drop in dispersion due to excessive addition may occur. As a result, it can be seen that the optimum amount of addition is 0.6 to 2.4 kg / m &lt; 3 &gt; in terms of bending strength, and the best bending strength is obtained at an addition amount of 0.6 kg / Able to know.

As shown in FIG. 3, the mortar of the present invention has an initial crack of more than 1.5 days due to measurement of drying shrinkage in a state constrained by the ring-shaped constrained drying shrinkage measuring apparatus (10) And the addition of the amount of the lyocell fiber is limited to 0.6 to 2.4 kg / m &lt; 3 &gt; so that the initial cracking is delayed as compared with the ordinary ocher mortar without added lyocell fiber. .

As shown in FIG. 3, in the case of the yellow mortar specimen (HN) containing no lyocell fiber, the initial crack occurred at 1.5 days. The yellow mortar specimen (HL-0.6, HL -1.2, HL-2.4, 0.6, 1.2 and 2.4 indicate the addition rates of the lyocell fibers, respectively), it can be seen that the initial crack occurs at a point exceeding 1.5 days. It is seen that the initial crack is delayed to improve the crack resistance.

The ring-shaped constrained drying shrinkage measuring apparatus 10 is a device for measuring initial cracks and the like as described above. The ring-shaped constrained drying shrinkage measuring apparatus 10 according to the present invention includes a ring-shaped constrained drying shrinkage measuring apparatus 10 as shown in FIGS. 4A and 4B, A circular inner mold 12 is formed at an upper portion of the inner mold 12 and a circular outer mold 13 formed at the same height as the inner mold 12 while being spaced apart from the outer mold 12 A filling portion 14 is formed in which the outer periphery of the inner mold 12, the inner periphery of the outer mold 13 and the space formed by the receiving plate 11 are filled with the yellow mortar, A silicone seal 15 is formed to seal the inner mold 12 and the outer mold 13 in the state where the filling part 14 is filled with the mortar and the inner periphery of the inner mold 12, One or more strain gages 16 are formed.

That is, in the ring-shaped constrained drying shrinkage measuring apparatus 10, the drying shrinkage characteristics of the yellow mortar confined by the inner mold 12 can be known.

The ring type constrained drying and shrinkage measuring apparatus 10 is constructed such that the inner mold 12 and the outer mold 13 are first installed on the receiving plate 11 and the filling unit 14 is filled with the yellow mortar, And the upper end of the outer mold (13) is sealed with a silicone seal (15). In this way, the silicon seal 15 is used to measure the initial cracking time or the like due to drying shrinkage characteristics by causing drying shrinkage in one direction.

The present invention is characterized in that an initial crack is generated in excess of 1.5 days in the ring-shaped constrained drying shrinkage measuring apparatus (10) having the above-described structure.

5, the value of P _{sca- v /} P _{sca- n} is limited to 0.25 to 0.7. P _{sca- v} corresponds to the crack area value in the loam mortar containing lyocell fiber, and P _{sca- n} corresponds to the crack area value in the _loam mortar without lyocell fiber. In other words, it can be seen that the mortar containing the lyocell fiber reduces the crack area by 30 to 75% as compared with the mortar containing the lyocell fiber. The control of the crack area finally results in the control of the lyocell fiber in the mortar mortar The crack resistance is improved. That is to say, by using the loess as a binder, the addition amount of the lyocell fiber is limited to 0.6 to 2.4 kg / m &lt; 3 &gt; so that the crack area can be controlled to be smaller than that of the ordinary ocher mortar without the addition of the lyocell fiber, will be.

The crack area shown in FIG. 5 can be measured by the plate-type constrained drying shrinkage measuring apparatus 20 as shown in FIGS. 6A and 6B. The plate-shaped constrained shrinkage shrinkage measuring apparatus 20 has an upper surface opened And is constituted by a housing 21 and at least one crack inducing portion 22 which protrudes in one direction from the lower face of the housing 21 to induce cracks in the state where the ocher mortar is restrained to measure the crack area thereof.

The area of the crack can be calculated using the crack progression and CAD program, which is a well-known technique, and a description thereof will be omitted.

That is, the plate-shaped constrained drying and shrinkage measuring apparatus 20 is constructed such that the mortar is filled and cured in the housing 21 and the crack is induced in the crack inducing portion 22 during the filling and curing of the mortar, By calculating the area of the crack, the addition of the lyocell fiber makes it possible to judge the control ability of cracking in the mortar.

As shown in FIGS. 6A and 6B, the crack inducing portion 22 induces cracks in the crack inducing portion 22 to be guided to the upper surface of the Hwangto mortar test specimen such that the side end face has a triangular shape.

As a result, it was found that the area of cracks due to drying shrinkage of the yellow mortar was actually measured by the plate-type constrained drying and shrinkage measuring device 20. As a result, it was found that the crack area decreased as the addition rate of the lyocell fiber increased, It can be seen that the crack area is reduced by 75% when compared with the mortar without the lyocell fiber. In order to improve the crack resistance by reducing the crack area, the value of P _{sca -v /} P _{sca- n} is limited to 0.25 to 0.7 in the present invention.

In the above-mentioned experiments, the yellow mortar was blended with yellow loam as a binder, so that the W / B was 40% and the S / B was 2.5, and the target slump value was 200 ± 10 mm. The tensile strength, the bending strength, Used in experiments.

10: ring-shaped constrained drying shrinkage measuring device
11: Support plate 12: Inner mold
13: outer mold 14: filling part
15: silicon seal 16: strain gage
20: Plate type constraint drying shrinkage measuring device
21: housing 22:

Claims (7)

Environmentally friendly mortar containing loess as a binder and reinforced lyocell fibers of 0.6 to 2.4 kg / m3.
The method according to claim 1,
Eco-friendly yellow mud mortar,
satisfies _{f sp -v / f sp -n>} 1.4 and, _-v f _sp is the lyocell fiber is equivalent to the tensile strength by including splitting it occurs in the yellow soil mortar specimen, f _{sp -n} is a lyocell fiber And the tensile strength at the time of splitting at the Hwangto mortar specimen not included.
The method according to claim 1,
Eco-friendly Horto Mortar
f _{r -v /} f _{r -n} > 1.2, f _{r -v} corresponds to the flexural strength value at the time of fracture in the yellow mortar specimen including the lyocell fiber, f _{r -n} does not include the lyocell fiber Which is characterized by a bending strength value at the time of fracture in a non-yellowing mortar specimen.
delete The method according to claim 1,
Eco-friendly yellow mud mortar,
The initial crack is generated in excess of 1.5 days,
The initial crack,
A silicone seal for sealing a circular inner mold, a circular outer mold spaced a certain distance from the outer periphery of the inner mold, and an upper surface opened by the inner mold and the outer mold; Characterized in that it is measured by a ring-shaped constrained drying shrinkage measuring device composed of a strain gauge.
delete The method according to claim 1,
Eco-friendly yellow mud mortar,
_{0.25 <P sca-v / P} sca-n < satisfies 0.7, and, P _sca-v will for the crack area values in the yellow soil mortar that contains lyocell fiber, P _sca-n are not contain lyocell fiber And the crack area value in the non-mortar mortar,
The crack area is,
Wherein the cracked area is measured as a crack area derived from a plate-shaped constrained drying shrinkage measuring device comprising a housing having an opened upper surface and one or more crack inducing portions protruding in one direction from the lower surface of the housing.

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