JP3536953B2 - Testing method for consistency of high fluidity concrete - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for testing the consistency of high-fluidity concrete, and more specifically, to evaluate the material separation resistance and gap permeability in addition to the freshness of high-fluidity concrete. It relates to the test method.

[0002]

2. Description of the Related Art The most commonly used evaluation test method for measuring the consistency of high fluidity concrete (deformation of fresh concrete, which is mainly determined by the amount of water, or the limit of fluidity) is as follows.
It is a slump flow test. The slump flow test,
It is performed in accordance with JISA1101.
As shown in (a), a sample is divided into three layers and packed into a slump cone b on a bottom plate a having a size of 80 cm square or more. Measure the flow time. In the case of ordinary high-fluidity concrete, it takes about 3 to 10 seconds.

[0003] After pulling up the slump cone, FIG.
When the concrete c spreads on the bottom plate as shown in (1), the longest part of the concrete spread and the spread in the direction perpendicular to the longest part of the concrete are measured, and these are averaged to obtain a slump flow. In the figure, d is a coarse aggregate. FIG. 2 shows an L-flow test apparatus. The test apparatus is formed in an L-shape, and a vertical portion e is filled with a sample by striking two layers five times each. After that, when the concrete h is drawn by pulling out the partition plate g for partitioning the vertical part e and the horizontal part f in the direction of the arrow, the transit time of the tip part at 5 cm and 10 cm from the opening is determined by an ultrasonic sensor, Also, when the flow stops, the amount of settlement of the vertical portion and the amount of movement to the tip are measured, and the L slump values Ls and L
The L flow time as the flow value Lf is converted into an L flow speed by each moving distance.

[0004] Reinforcing flow test is as shown in FIG. 3, the L flow high fluidity concrete in the test device has Haisuji in three dimensions 7cm interval rebar i of D ₁₃ at a portion flowing rebar amount of high fluidity concrete This is a test for evaluating the filling property of high fluidity concrete by arranging it in a horizontal portion f where the fluid flows. FIG. 4 shows a V funnel test, in which a concrete of about 10 liters is packed in a single layer without hitting or hitting the funnel j, and a discharge port k having a narrowed lower section of the funnel.
Is released and the concrete flow time is measured.

FIG. 5 shows a ring penetration test, in which a ring m made of round steel and a supporting rod n are suspended via a weight o, and penetrated into a sample concrete q in a cylinder p by its own weight. Evaluate the consistency of the concrete sample. FIG. 6 shows a cylinder penetration test, in which a cylindrical penetration meter t provided with an opening s for mortar circulation on the side surface of a hollow cylinder r with a closed bottom is inserted into concrete, and the opening s
The consistency of concrete is evaluated based on the amount of mortar that has flowed in.

[0006] In addition to the above, various test methods have been proposed. However, despite the importance of material separation resistance and gap permeability in high fluidity concrete, they have not yet been standardized.

[0007]

A number of test methods have been proposed for evaluating the filling properties of high-fluidity concrete, such as the material separation resistance and the gap-passing property of the concrete. Even in such cases, special test equipment was required, the test method was troublesome, and many were unsuitable at construction sites.

[0008] The present invention has been proposed in view of such circumstances, and it is an object of the present invention to provide a method which is not so different from the conventional slump flow test in the material separation resistance and gap permeability of high fluidity concrete. Another object of the present invention is to provide a method for testing the consistency of high fluidity concrete, which can be quantitatively evaluated by the method described above.

[0009]

To achieve the object of the SUMMARY OF THE INVENTION According to the high-flowing consistency testing method of the concrete according to the invention of claim 1, performed slump flow test of the high-flow concrete (i), ( B) Slump cone
To so that given a mechanical resistance at the time of spread of the co <br/> Nkurito by a vertical leg that is arrayed at equal intervals in the circumferential direction on the outside of
Barrier slump flow test of the high fluidity concrete
And the spread of the concrete and the inside and outside surrounded by the vertical leg pieces in the above-mentioned (b) barrier slump flow test when compared with the above-mentioned (a) slump flow test.
From the amount of coarse aggregate in the concrete on the side
This is to evaluate the separation resistance of the sheet .

Further, according to the high flowing consistency testing method of the concrete according to the invention of claim 2, subjected to slump flow test of the high-flow concrete (A), this and
Mushroom slump flow FL and 50cm flow time FT
₅₀ is measured, said disposed at a predetermined position of the barrier formed by arrayed vertical leg for each circumferentially equal division position of (b) band ring
Performs barrier slump flow test of the high fluidity concrete, the slump flow BL in this case, 50 cm to measure the flow time BT ₅₀ and the inner and outer coarse aggregate amount B _n of the barrier, the slump flow test of the (a) of (b) barrier slump using measurements of flow test is to evaluate the consistency of the high fluidity concrete.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described with reference to the drawings showing the most preferred embodiments of the present invention. FIG. 7 shows a test jig (hereinafter, referred to as a barrier) used in the consistency test method for high-fluidity concrete according to the present invention. The circle in the band 1 having a wall thickness of 2 to 5 mm, an inner diameter of 290 mm, and an outer diameter of 300 is shown. Vertical leg pieces 2 made of round steel are provided at positions divided into 16 equal parts and are welded. The barrier can be manufactured by changing the number of round bars.

Next, the test method of the present invention will be described. The terms used in this test are defined as follows.

[0013]

(Equation 1)

[0014] BL: Slump flow value with barrier (cm) FL: Slump flow value without barrier (cm)

[0015]

(Equation 2)

[0016] G _i: Barrier internal coarse aggregate weight ratio G _o: Barrier external coarse aggregate weight ratio 50cm flow time difference = BT ₅₀ -FT ₅₀ BT _50: barrier to 50cm flow time decor (seconds) FT _50: a barrier Table 1 shows the relationship between the quality of the high fluidity concrete and the evaluation items.

In the test, after the high-fluidity concrete is kneaded by a mixer, all of the mixture is discharged to a kneading plate, and after sufficient stirring is completed, the amount of air and slump flow are measured as in the case of ordinary concrete. For the slump test, measure the 50 cm flow time. In addition to this measurement, a barrier flow test is performed by disposing the barrier 3 composed of the belt ring 1 and the vertical leg piece 2 made of round steel as described above outside the slump cone 4. In the figure, reference numeral 5 denotes a bottom plate of 80 cm square or more on which the slump cone 4 and the barrier are placed.

The test method conforms to JISA1101, and the barrier 3 is installed outside the slump cone 4 and the sample inside the slump cone 4 is packed in three layers.
Poke 0-5 times with a stick against each layer. The fixing projection provided on the bottom of the cone is removed in advance so as not to hit the barrier 3 when the cone 4 is pulled up. (See FIG. 8 (a).) The beginning of pulling up the cone 4 is set to 0, and a 50 cm flow time is measured.

When the concrete flowing on the bottom plate 5 comes to a standstill, the longest part of the spread of the concrete 6 and the spread in a direction orthogonal to the same part are measured, and these are averaged to obtain a slump flow. Further, the amount of coarse aggregate 7 in the concrete inside and outside of the expanded concrete is measured.
(See FIG. 8 (b).) According to the test method of the present invention, the barrier of the concrete 3 mechanically gives resistance to the spread of the concrete, and the spread of the concrete when compared with the normal slump flow test, In order to evaluate the separation resistance, in the case of high quality high fluidity concrete, the passage rate is close to 100%,
The 50 cm flow time hardly changes, and the degree of separation is close to 1.

Next, Table 1 shows the relationship between the quality of the high fluidity concrete and the evaluation items.

[0021]

[Table 1]

[0022]

According to the method for testing the consistency of high-fluidity concrete according to the present invention, as described above, the slump flow test of high-fluidity concrete is performed to provide mechanical resistance when the concrete spreads.
By evaluating the concrete spreading and separation resistance when compared to the normal slump flow test, it is possible to quantitatively evaluate the characteristics more than the conventional slump flow test without using special test equipment, A consistency test of high-fluidity concrete is easily performed at a construction site.

Further, according to the present invention, since the concrete flows in all directions from the center of the slump cone, there is less error and the reproducibility is reduced as compared with other test methods relating to the gap passing property in which the concrete flows only in one direction. Are better. Further, the material separation resistance of high-fluidity concrete can be quantitatively determined by the degree of separation (ratio of coarse and coarse aggregates).

The gap permeability of the high-fluidity concrete can be evaluated by the passage rate.
It can be evaluated by the cm flow time difference. Thus, the overall evaluation of the consistency of the high fluidity concrete is carried out using the above-mentioned degree of separation and passage rate. That is, unless both of them satisfy the predetermined numerical value at the same time, they cannot be said to be sound high-fluid concrete. According to experiments, in the high fluidity concrete having a target slump flow of about 60 to 70 cm, the barrier B shown in FIG. 8 has a degree of separation of 1.3 or less, preferably 1.2 or less, and a passing rate of 70% or more, preferably 80% or more.

[Brief description of the drawings]

FIGS. 1A and 1B show an outline of a slump test.
(A) is a perspective view showing a state in which the slump cone is filled with fresh concrete, and (B) is a perspective view showing a state in which the slump cone is pulled up.

FIG. 2 is a perspective view showing an L flow test apparatus.

FIG. 3 is a perspective view showing a bar arrangement L flow test device.

FIG. 4 is a perspective view of a V funnel test apparatus.

FIGS. 5A and 5B are perspective views of a ring penetration test device and a ring used in the device, respectively.

FIGS. 6A and 6B are a front view and a side view of a cylindrical intrusion meter, respectively.

FIGS. 7A and 7B are a plan view and a front view of a barrier, respectively.

8 (a) and (b) respectively show a barrier flow test state of the present invention, (a) shows a state in which a slump cone is filled with concrete in the barrier, and (b) shows a state where the cone is pulled up from the barrier It shows the state that it was turned on.

[Explanation of symbols]

1 belt 2 vertical leg pieces 3 barrier 4 Slump cone 5 Bottom plate 6 concrete 7 Coarse aggregate

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) G01N 11/00 B28C 7/00 G01N 33/38

Claims (2)

(57) [Claims] (1 ) A slump flow test of high fluidity concrete is performed. (B) A slump flow test is carried out at equal intervals around the outside of the slump cone.
The high fluidity concrete burrs by a vertical leg at the spread of the concrete in the so that given a mechanical resistance was
Performs A slump flow test, the when compared with slump flow test of the (b)
(B) The spread of the concrete in the barrier slump flow test and the inner and outer cores surrounded by the vertical leg pieces.
A method for testing the consistency of high fluidity concrete , comprising evaluating the separation resistance of the high fluidity concrete from the amount of coarse aggregate in concrete. Wherein (b) is performed slump flow test of the high fluidity concrete, the slump flow FL at this time, and 50cm to measure the flow time FT _50, (b) band vertical leg in the circumferential direction such division every position of the ring A barrier formed by arranging pieces is arranged at a predetermined position, and the high flow concrete is provided.
Performs barrier slump flow test of the over bets, barrier slump flow BL in this case, 50 cm to measure the flow time BT ₅₀ and the inner and outer coarse aggregate amount B _n of the barrier, the slump flow test of the (A) and (B) evaluate the consistency of the high flow concrete using measurements of slump flow test, consistency testing method of the high fluidity concrete, characterized in that.