WO2015126059A1

WO2015126059A1 - Hybrid concrete composition and method for preparing same

Info

Publication number: WO2015126059A1
Application number: PCT/KR2015/000272
Authority: WO
Inventors: 윤경구
Original assignee: 강원대학교산학협력단
Priority date: 2014-02-20
Filing date: 2015-01-12
Publication date: 2015-08-27
Also published as: KR20150098444A; KR101578144B1

Abstract

The present invention relates to a hybrid concrete composition and a method for preparing the same, the hybrid concrete composition being prepared by mixing 5-10 parts by weight of silica fume for enhancing the high strength and high durability of concrete and mixing 3-9 parts by weight of latex for suppressing the occurrence of cracking due to film shape and an aggregation effect, on the basis of 100 parts by weight of cement that forms typical concrete having slumps of about 40-120 mm, thereby maintaining similar performance compared to conventional latex modified concrete. Accordingly, the present invention is capable of significantly reducing the mixing amount of latex compared to the amount of latex used in forming conventional latex modified concrete, thereby improving economic efficiency.

Description

Hybrid concrete composition and preparation method thereof

The present invention relates to a hybrid concrete composition, and more particularly, to a hybrid concrete composition and a method for manufacturing the same, incorporating organic latex and inorganic silica fume to maintain high strength and high durability.

Recently, due to the problem of frequent damage to the concrete pavement has been increasing the application of cross-linked pavement of the concrete-based excellent durability, among which high-performance concrete incorporating latex modified concrete and silica fume has been used.

The latex modified concrete (Latex Modified Concrete) is a concrete made by mixing a certain amount of latex in ordinary concrete, it prevents salt and moisture penetration due to low permeability to protect the concrete slab from reinforcing corrosion, etc., not only to improve durability but also high strength Due to the high density, it is easy to maintain and increase common training.

When the latex is added to Portland cement, the fluidity increases even at a lower unit quantity than ordinary concrete, and the cement hydrate and the aggregate are interconnected to increase adhesion by forming a film film by filling the micropores inside the concrete.

When the Portland cement is dried, the cement hydrate shrinks to cause microcracks in the cement hydrate, and the propagation of the microcracks decreases the tensile force of the concrete and increases the penetration of chlorides or harmful chemicals. However, latex-modified concrete is filled with latex particles around the aggregate and aggregates in the form of a film covering the cement hydrate, thereby filling the microcracking voids in the cement hydrate and inhibiting the propagation of the microcracks. The permeability resistance is increased while increasing the bond strength.

The latex is generally mixed about 15% of the weight of cement based on solid content, which is a factor of increasing about 4 times based on the cost of concrete materials only. Furthermore, the price of petroleum is soaring and the latex value of chemicals soars to 1,800 won / When reaching 1 kg, the production of 1 ㎥ of concrete, the latex value only 230,400 won / ㎥ occurs because the production cost is increased, there was a problem that the economic efficiency is lowered.

In addition, latex-modified concrete is produced and supplied by using mobile mixers due to its mixing properties, and production costs are further increased due to the operation of mobile mixers, transportation of materials, and operation of materials supply equipment. There was a problem of falling economic efficiency.

Silica Fume mixed in the latex modified concrete is an ultra-fine particle industrial by-product generated when manufacturing silicon (Si), pelosilicon (FeSi), silicon products, etc., which is 7-10% by weight of cement. When mixed, the powder of silica fume, which is about 1/80 of the cement powder, causes the microfiller effect to fill the pores of the cement particles, making the interior more compact by the pozzolanic reaction, which increases strength, decreases permeability, and enhances durability. However, it is used with high fluidizing agent because of its high specific surface area and poor workability.When blending in a site batcher plant, it is mixed with other concrete materials or mixed with concrete (leather concrete). Silica fume is not evenly dispersed, causing many problems.

[Preceding technical literature]

Republic of Korea Patent Publication No. 10-2006-0070618

Republic of Korea Patent Publication No. 10-0755272

In view of the above-described conventional problems, an object of the present invention is to mix 5-10 parts by weight of silica fume on the basis of 100 parts by weight of cement for forming ordinary concrete of about 40 to 120 mm of slump, It is to provide a hybrid concrete composition and a method of manufacturing the same by mixing 3 to 9 parts by weight to produce a hybrid concrete similar in performance to conventional latex modified concrete.

In addition, another object of the present invention is to provide a hybrid concrete composition and a method for manufacturing the same that can significantly improve the economics by significantly reducing the construction cost by significantly reducing the amount of latex mixed than when forming a conventional latex modified concrete. .

The hybrid concrete composition of the present invention,

Ordinary concrete formed by mixing water, cement, and aggregate so as to have a slump of 40 to 120 mm;

Silica fume to be mixed in 5 to 10 parts by weight based on 100 parts by weight of the cement to form the ordinary concrete in the normal concrete;

The silica fume is mixed with 3 to 9 parts by weight based on 100 parts by weight of the cement to form a normal concrete mixed concrete mixed with latex to suppress the occurrence of cracks.

According to the present invention, by mixing 5 to 10 parts by weight of silica fume based on 100 parts by weight of cement to form a normal concrete of about 40 to 120mm slump to improve the high strength and high durability of the concrete, and 3 to 9 parts by weight of latex By mixing and suppressing the occurrence of cracks by the shape of the film and the cohesive effect can maintain the performance similar to the conventional latex modified concrete, users can improve the reliability of the product.

In addition, according to the present invention, it is possible to significantly reduce the cost of construction by significantly reducing the amount of latex mixed than when forming a conventional latex modified concrete can have the advantage of improving the economics.

1 is a flow chart of the present invention

2 is a view for forming the ordinary concrete of the present invention

3 to 4 is a view showing a first embodiment of the mixing portion of the present invention

5 is a view showing a second embodiment of the mixing unit of the present invention;

6 is a shortening process diagram of the present invention hybrid concrete

7 is a view showing the result of measuring the air volume of the present invention hybrid concrete

8 to 10 is a slump photograph of ordinary concrete and mixed concrete and hybrid concrete of the present invention

11 is a view showing a change in compressive strength of the present invention hybrid concrete

12 is a view showing the change in flexural strength of the present invention hybrid concrete

13 is a view showing the penetration resistance of the present invention hybrid concrete

* Description of the symbols for the main parts of the drawings *

10: Batcher Plant 40: Ready Concrete Truck

60,60 ': mixing part

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings. 1 is a flow chart of the present invention.

Hybrid concrete composition of the present invention, the concrete is formed by mixing water, cement, aggregate so that the slump 40 ~ 120mm;

The silica fume is mixed with 3 to 9 parts by weight based on 100 parts by weight of the cement to form the ordinary concrete mixed with the mixed concrete is configured to include a latex to suppress the occurrence of cracks.

The following describes the hybrid concrete manufacturing process of the present invention configured as described above.

First, as shown in Figure 2, by mixing and mixing the water, cement, aggregate supplied from the batcher plant 10, respectively, to form a slump 40 ~ 120mm ordinary concrete, the cement is produced by the domestic S company As portland cement, a specific gravity of 3.15 and a powder degree of 3,400 cm 2 / g were used.

The aggregate is a coarse aggregate of 13 mm or more and a fine aggregate of 13 mm or less, and the specific gravity of the coarse aggregate is 2.61, the granulation rate is 6.23, and the specific gravity of the fine aggregate is 2.60, and the granulation rate is 3.02.

When the ordinary concrete is transferred to the construction site by the ready-mixed concrete truck 40, silica fume is mixed into the normal concrete of the ready-mixed concrete truck 40, wherein the silica fume is based on 100 parts by weight of the cement forming the normal concrete. 5 to 10 parts by weight is mixed, and as shown in FIGS. 3 to 5, the mixing parts 60 and 60 'are mixed to form mixed concrete.

Table 1

division		Test result
Physical properties	Density (kg / ㎥)	130 ~ 350 kg / ㎥
	importance	2.2 ± 0.2 (20 ℃)
	Ignition loss (%)	3.45% or less
	Powder level (㎠ / g)	About 150,000 ~ 300,000 cm2 / g
	Constellation	90% or more spherical
	Particle size (㎛)	1 μm
	Unit weight (kg / ㎥)	250 ~ 300 kg / ㎥
	chief ingredient	Silicon (85% or more of Si component)
Chemistry	SiO2 (%)	85-95
	Al2O3 (%)	1.5 or less
	Fe2O3 (%)	3.0 or less
	CaO (%)	0.7 or less
	MgO (%)	2.0 or less
	SO3 (%)	0.2 or less
	1 g.loss (%)	3 or less

Table 1 shows the physical and chemical properties of the silica fume. When the silica fume is mixed in ordinary concrete with 85% or more silicon component, the silica fume may be filled between cement particles to enhance the high strength and high durability of concrete. .

The mixing unit 60, while the shaft 61 is rotated by the power of the motor inside the ready-mixed truck 40, while the mixing member 62 is radially connected to the shaft 61 at least one stage while rotating. Usually, concrete and silica fume are mixed to form mixed concrete.

In addition, the mixing unit 60 ′ is supplied with ordinary concrete from the ready-mixed concrete truck 40 to the hopper 63 and moved to the mixer unit 65 by the stirring rotating member 64, and mixed into the ordinary concrete. Silica fume can be mixed to form mixed concrete.

The latex is mixed into the mixed concrete formed by the above process, and the latex is mixed into 3 to 9 parts by weight based on 100 parts by weight of the cement for forming the ordinary concrete, and mixed with the mixing parts 60 and 60 '. To form concrete.

TABLE 2

Item	unit	Result	Test Methods
All solids	%	46.9	KS M 6516: 2011
Latex Viscosity ((25 ± 1) ℃)	mPa.s	56	KS M 6516: 2011
PH ((25 ± 1) ℃)	-	10.5	KS M 6516: 2011
Coagulation powder	%	0.02	KS M 6516: 2011
Freeze-year degree ((-10 ± 1) ℃)	%	0.02	KS M 6403: 2008 (*)
Surface Tension ((23 ± 2) ℃)	mN / m	32.0	KS M 1071-4: 2007 (ring method)

Table 2 shows the physical properties of the latex, since the latex contains a defoaming agent, the bubbles are considerably reduced, and care must be taken because long-term exposure to the air may cause a latex protective film film due to moisture evaporation, resulting in slump loss.

Since the mixing parts 60 and 60 'forming the hybrid concrete are the same as those of the mixing parts 60 and 60' forming the mixed concrete, description thereof is omitted and alumina is used to shorten the curing time of the concrete in the hybrid concrete. The mixed material formed by mixing any one or more of the ultra fast clinker powder, the amorphous alumina super fast clinker powder, and the Awin super fast clinker powder is further mixed and mixed into the mixing unit 60 (60 '). It can be mixed with 5 to 45 parts by weight based on 100 parts by weight of cement to form concrete.

Here, it was described that the silica fume, latex, and mixed materials are added to the ordinary concrete in order to mix, but after changing the order of silica fume, latex and mixed materials in any of the composition of silica fume, latex and the mixed material. The mixture may be mixed or silica fume, latex, or mixed materials may be added together and mixed at once.

When the amount of the mixed material is mixed in 5 to 15 parts by weight based on 100 parts by weight of cement to form the normal concrete, the crude steel concrete can be prepared, the amount of the mixed material based on 100 parts by weight of cement to form the normal concrete When mixed to 15 to 25 parts by weight, can be prepared super-tough steel concrete, when the mixed material is mixed with 25 to 40 parts by weight based on 100 parts by weight of cement to form a normal concrete, super-speed concrete is prepared You can do it.

As shown in FIG. 6, the hybrid concrete may be shorted through a shorting guide member 70 mounted on the ready-mixed truck 40 and a concrete pump car (not shown) to form a structure.

The shorting with the shorting guide member 70 is because the slump can be reduced while dissipating the bubbles contained in the hybrid concrete.

Example

1) Slump and air volume measurement

The hybrid concrete of the present invention, as shown in Table 3, the unit binder was 390 (kg / ㎥), the aggregate aggregate 56%, W / B was 39% to secure the fluidity. As for the aggregate aggregate rate of 56%, 13mm crushed aggregate was used, and latex having 46.9% solids was used.

Mixing and mixing the aggregate, cement, and water to form a slump 40 ~ 120mm of ordinary concrete, based on 100 parts by weight of cement to form a normal concrete in the normal

concrete latex

3, 5, 7 parts by weight and silica fume 6, The compounding table mix | blended while changing the amount of 7, 8 weight part mixture is shown.

Here, if the silica fume is less than 5 parts by weight, the filling effect is small and does not exhibit high strength and high durability. If the silica fume is more than 10 parts by weight, it is because the small voids in the concrete are all filled and remain uneconomical. This is because the filling effect and the coagulation effect of the pores are low, so that the ability to suppress cracking is lowered.

TABLE 3

	W / B (%)	Binder	S / a (%)	Unit Weight (kg / ㎥)						SP (%)
	W / B (%)	Binder	S / a (%)	W	C	SF	Latex	S	G	SP (%)
SF6LA3	39	390	56	138.9	367	23.4	24.9	976	755	0.65
SF6LA5				130	367	23.4	41.6	964	746
SF6LA7				121.2	367	23.4	58.2	953	737
SF7LA3				138.9	363	27.3	24.9	975	754
SF7LA5				130	363	27.3	41.6	964	745
SF7LA7				121.2	363	27.3	58.2	952	737
SF8LA3				138.9	359	31.2	24.9	974	754
SF8LA5				130	359	31.2	41.6	963	745
SF8LA7				130	359	31.2	58.2	952	736

The air amount and the slump change of the hybrid concrete according to the mixing amount of the

latex

3, 5, 7 parts by weight and

silica fume

6, 7, 8 parts by weight was measured immediately after mixing, and the air amount measurement result according to the mixing of latex and silica fume is shown in FIG. 7. Shown.

8 to 10, the slump of the hybrid concrete can be seen that the slump of the normal concrete, mixed concrete and hybrid concrete is different, by using a high performance fluidizing agent in the hybrid concrete of the target slump value of 100 ~ 180mm The change in air volume due to the mixing of latex and silica fume does not show a big difference in this experiment, and satisfies all of the range of 3 ~ 9%, the air volume standard range proposed by Korea Expressway Corporation.

2) Compressive strength measurement

Compressive strength of the hybrid concrete was measured at 28 days, 56 days, the results are shown in FIG.

As a result of the measurement, as the silica fume increased, the compressive strength increased significantly, and the compressive strength decreased with the mixing of latex. Due to the high specific surface area of silica fume, it is believed that the compressive strength is increased by filling the cement particles with the added amount. It can be seen that in the formulation in which 6 parts by weight of silica fume is added, it is close to 27 MPa, which is the reference compressive strength of the crosslinking packaging, and higher than 27 MPa, which is the reference compressive strength of the crosslinking packaging, when incorporating 7 parts by weight or more.

The latex contained in the hybrid concrete forms a film film around the aggregate, and shows a tendency not to change because it is destroyed in the film film when broken, and latex does not contribute to the compressive strength by forming a soft film film inside the concrete. It can be seen that.

3) Bending Strength Measurement

The flexural strength of the hybrid concrete measured tensile strength at age 28, and the results are shown in FIG.

As a result, the flexural strength increased with increasing silica fume, and the flexural strength tended to increase slightly with latex incorporation. In addition to the filling effect due to the mixing of silica fume, it is considered that the flexural strength is increased because latex forms a film film on the material inside the hybrid concrete to increase the adhesion between the materials, and the strength exceeds the road paving standard of 4.5Mpa. It can be seen that it satisfies the requirements.

4) Chlorine Ion Penetration Resistance Measurement

The chlorine ion penetration resistance test of the hybrid concrete was measured based on the age of 28 days, and the chlorine ion permeation resistance results of the age 28 day hybrid concrete according to the mixing of latex and silica fume are shown in FIG. 13.

As silica fume increases, latex increases, and chlorine ion permeation resistance tends to increase significantly. In addition, silica fume of an inorganic material having a high specific surface area and latex, an organic material, are filled with cement particles to increase resistance.

Based on the classification given in KS F 2711, except for one variable of S6L7, it is very low because it is less than 1000 coulombs.

5) Measurement result

Considering the above compressive strength, silica fume content exceeds 7 parts by weight and exceeds 30 MPa, higher than 27 MPa, which is Korea's road paving standard, and flexural strength is 5.0 MPa higher than 4.5 MPa, This is due to the excellent filling effect of silica fume and latex.

In addition, when analyzing the chlorine ion penetration resistance test results, it can be seen that the chlorine ion permeation rate is lowered to 400 ~ 500 Coulomb range while the silica fume incorporation rate exceeds 7 parts by weight.

Therefore, the compressive strength, flexural strength, chlorine ion penetration resistance test results are comprehensively analyzed, considering the requirements of the Korea Highway Corporation road pavement standard, and considering the economics, silica fume content 7 parts by weight, latex content 5 weight It can be seen that the addition of the optimum formulation, Table 4 shows the optimum mix of hybrid concrete.

Table 4

	W / B (%)	Binder (kg / ㎥)	S / a (%)	Unit Weight (kg / ㎥)						SP (%)
	W / B (%)	Binder (kg / ㎥)	S / a (%)	W	C	SF	Latex	S	G
SF7LA5	39	390	56	130	363	27.3	41.6	964	745	0.65

SF7LA5: 7 parts by weight of silica fume, 5 parts by weight of latex

W / B: Water-Binder Ratio

Binder: The sum of cement and silica fume

S / a: fine aggregate to aggregate ratio

W: Quantity per unit volume

C: amount of cement per unit volume

SF: Silica fume amount per unit volume

Latex: amount of latex, including solids and water, per unit volume

S: fine aggregate amount per unit volume

G: Coarse aggregate amount per unit volume

SP: amount of fluidizing agent mixed with binder

The hybrid concrete formed by the optimal combination of silica fume and latex is usually used as a cross-linking, and requires the physical properties of Table 5, by mixing silica fume and latex, the strength and endurance characteristics are quite good, It can satisfy the air volume standard.

Table 5

Item	Test Methods	unit	standard
slump	KS F 2403	cm	10-18
Air volume	KS F 2409	%	3 ~ 9
28 days compressive strength	KS F 2405	MPa	27 or more
28 days flexural strength	KS F 2408	MPa	4.5 or more
28 days adhesion strength	Direct pull test	MPa	1.4 or higher
Special characteristics	ASTM C 1202	coulomb	1000 coulombs or less
Freeze thawing	KS F 2456	Durability index	80% or more
Surface peeling resistance	ASTM C 672	kg / ㎡	0.1 or less

In the present invention, the above embodiment is an example, and the present invention is not limited thereto. Anything that has substantially the same configuration as the technical idea described in the claims of the present invention and achieves the same effect will be included in the technical scope of the present invention.

Claims

Ordinary concrete formed by mixing water, cement, and aggregate so as to have a slump of 40 to 120 mm;

Silica fume to be mixed in 5 to 10 parts by weight based on 100 parts by weight of the cement to form the ordinary concrete in the normal concrete;

Hybrid concrete composition characterized in that it comprises a latex to mix the 3 to 9 parts by weight based on 100 parts by weight of cement to form the normal concrete in the mixed concrete mixed with silica fume.
The method according to claim 1,

Hybrid concrete composition characterized in that it further comprises a mixed material mixed in 5 to 45 parts by weight based on 100 parts by weight of cement to form a normal concrete to shorten the curing time of the concrete in the concrete.
The method according to claim 2, wherein the mixed material,

Hybrid concrete composition, characterized in that formed by mixing any one or more of the alumina-based ultra-fast clinker powder, amorphous alumina-based ultra-fast clinker powder, Awin-based ultra-fast clinker powder.
Mixing water, cement, and aggregate so as to have a slump of 40 to 120 mm to form ordinary concrete;

Mixing 5-10 parts by weight of silica fume based on 100 parts by weight of the cement for forming the ordinary concrete in the ordinary concrete, and then mixing the mixture with a mixing part to form a mixed concrete to promote high strength and high durability;

Hybrid concrete comprising the step of mixing 3 to 9 parts by weight of latex on the basis of 100 parts by weight of cement to form the ordinary concrete in the mixed concrete, and then mixing into the mixing part to form a hybrid concrete to suppress the occurrence of cracks Method for preparing the composition.
The method according to claim 4,

Hybrid concrete composition manufacturing method characterized in that it further comprises a mixed material mixed in 5 to 45 parts by weight based on 100 parts by weight of cement to form a normal concrete to shorten the curing time of the concrete in the concrete.
The method according to claim 5, wherein the mixed material,

Method for producing a hybrid concrete composition, characterized in that formed by mixing any one or more of alumina-based super fast clinker powder, amorphous alumina super fast clinker powder, Awin-based super fast clinker powder.
The method according to claim 4, The mixing unit,

A shaft rotating with power of a motor in a ready-mixed concrete truck into which the normal concrete and silica fume and mixed concrete and latex are introduced;

At least one stage radially formed on the shaft, and including a mixing member for mixing ordinary concrete, silica fume, mixed concrete, and latex while rotating in a rotational direction of the shaft.
The method according to claim 4, The mixing unit,

A hopper into which the ordinary concrete, silica fume, mixed concrete, and latex are introduced;

Hybrid concrete composition manufacturing method characterized in that it comprises a mixing member for mixing the normal concrete and silica fume and mixed concrete and latex introduced into the hopper by the rotation of the screw.